Assessment of China’s Green Public Procurement Policy on Forest Products How to effectively meet the globally increasing demands for forest products and meanwhile put forest resources and eco-environment under better protection for achieving the balance between protection and growth is a long-term challenge in face of the international community.China is the largest country in world forest products import/export.In such sense,the realistic state and future orientation of China’s forest product procurement policy will impose considerable impacts on and play a significant role in forestry industry development in China as well as the global sustainable forestry development.In view of the state and trend of forest product procurement by Chinese enterprises,the paper analyzed the problems and challenges facing China’s green procurement of forest product based on the results of field survey carried out for different types of forest product processors,including customers’ weak awareness of green consumption,deficient green procurement resources of forest products,high prices of green procured products,limited list of forest products under green procurement,lack of laws and regulations for green public procurement and lack of policy support and green market planning.At the same time,by comparing and learning the experiences and lessons of the UK,Japan,France, Netherland and other countries in green public procurement of forest products,the paper,in line with the national and forest conditions in China,proposed some policy recommendations,e.g. strengthening dissemination and education for raising the awareness of green consumption, updating laws and regulations for government green procurement,adopting marketing means to encourage green enterprises development,updating green product lists to incorporate more green procurement enterprises into government green procurement programs,establishing monitoring and execution mechanism for green procurement and enhancing the oversight of green procurement,with the aim to facilitate China’s green procu...Countermeasure Strategy for China’s Wood Enterprises to Meet Timber Legality Requirements As the global forest issues and illegal logging have increasingly aroused the concerns of the international community,the US Lacey Act Amendment and the EU Timber Regulation poses requirements for the legality of timber.The paper described the background of timber legality issue,analyzed the specific requirements of the US and the EU for timber legality,and pointed out their negative impacts on China’s wood enterprises.Based on the analyses,the authors came up with the approaches that China’ s wood enterprises could adopt to meet legality requirements,and proposed the specific suggestions on how enterprises respond to the requirements for legality with an eye for the difficulties that they are confronting with.
Comparative Studies on US Lacey Act Amendment and EU Timber Regulation The US and EU markets are the main destinations of Chinese forest products.Through analyzing the similarities and differences between the US Lacey Act Amendment and the EU Timber Regulation,the paper focused on how to realize better compatibility and practicality of Chinese timber legality verification scheme in terms of verification standard setting,verification procedures,pilot work of timber legality verification scheme,capacity-building trainings and studies on key problems.
Effects of Land Uses on Soil Organic Carbon and Carbon Pool Management Index Carbon management index（ICM） is used to evaluate the scientificity of soil management.Soil organic carbon（SOC） and readily oxidized carbon （ROC） contents under Leucaena leucocephala stand, Acacia glauca stand,Acacia auriculiformis stand, Azadirachta indica stand,wasteland and dry cropland were determined and their ICM were calculated.The results showed that the SOC and ROC contents under the 6 land use types were 4.22-5.92 g·kg-1 and 1.34-2.33 g·kg-1,respectively.No significant differences in SOC contents among these land uses were observed.The ROC contents under the 4 types of woodland,however,were significantly higher than these under dry cropland or wasteland（P<0.05）. The ROC were high significantly（P<0.001） correlated（R2 is 66.3%） with SOC.Compared with wasteland,the ICM ranged from 1.77 to 2.36 under these woodlands,and 0.99 under dry cropland.It is revealed that the litter quantity and land management under these land uses may be the key factors resulting in the variation of ROC.At ecological fragile region of Dry-hot Valley,closure management is useful to sequestrate C in woodland soils.However,the management systems for soil carbon pool under dry cropland are not in a sound way.
Study on Habitat Forest Type and Plant Diversity of Sichuan Snub-nosed Monkey in Shennongjia National Nature Reserve The experimental plots in representative areas of the Shennongjia Nature Reserve were established.The forest communities in Shennongjia were investigated by using TWINSPAN.The plant communities in these plots were investigated to discern the pattern of species diversity distribution along the altitudinal gradient.Theα-diversity andβ- diversity were calculated by using the data collected. Theα-diversity of the tree layer peaked in the evergreen broadleaved forest zone at low-elevation, theα-diversity of the shrub layer increased gradually at first and then decreased along the altitudinal gradient,while theα-diversity of the herb layer peaked in mid-altitude.Theβ-diversity peaked at mid-elevations where the composition of edificatory species changed.The transition zone was characterized by relatively high levels of species diversity and species turn-over rate.The overall species richness peaked in mid-altitude.The results of this research could provide a sound basis for reserve management and planning,as well as preservation of Sichuan snub-nosed monkey in this reserve.
A Preliminary Study on Colletorichum from Horned Gallnut A pathogenic fungus Colletorichum gloeosporioides(Penz.) Sacc isolated from horned gallnut,a Chinese gallnut from Yunnan Province,was reported for the first time.Its morphological and molecular biological characteristics were identified, and its damage status and mycelium characters on gall and mydium were described.The pathogenic fungi C.gloeosporioides Sacc belongs to Melanconiales(Deuteromycotina:Coelomycetes).
Study on Litter Water Interception Capacity of Phyllostachys edulis Plantations with Different Densities The litter amount and the water holding characteristic parameters,such as the maximum water holding capacity and rate,the water absorption rate and the modified interception amount of Phyllostachys edulis plantations with four densities were studied in Huangshan district.The results are as follows:The total amount,thickness and natural water content of litters under all the four stands tested were different.The total litter amount in different stands ranged between 3.98 t·ha-1 to 6.00 t·ha-1, which in the stand with the density of 3 000 stems·ha-1 was the most.The ratio of maximum water-holding capacity of litter in various stands ranged from 317.09%to 347.58%.The maximum water holding capacity of litter in the stand with the density of 3 000 stems·ha-1 was 20.70 t·ha-1. By analyzing,the relationship between the water holding capacity of litter and the immersion time followed the equation of:S = alnt + b（a is the coefficient;b is the constant term）.The relationship between the water absorption speed of the litter and the immerse time followed the equation of: V = ctd（c is the coefficient;d is the exponential term）.The litter water capacity increased rapidly within the first four hours,and then increased slowly.The results also showed that the hydrological character of litter was positively related to density in Ph.Edulis forest.Therefore, it is important to choose appropriate density for enhancing the eco-hydrological benefits of litter layer in Ph.edulis forest.
Relationship between Arthropods in Forest Litter and Forest Health As an important part in forest ecosystems, the arthropod communities in the forest litter are closely related to forest health.Based on the ecological function,community structure and biology of the arthropods,we discuss the theoretical basis for the selection of particular groups of arthropods as bio-indicators in this paper,and suggest that the evenness and richness of Collembola(Collembolan), Coleoptera(Beetle) and Hymenoptera(Ant) can serve as forest health indicators.In terms of the relationship between forest litter arthropods and forest health,we summarize the main groups of forest litter arthropods suitable as bio-indicators and their ecological functions in forest ecosystems,and subsequently introduce a simple and accurate new method for selecting forest health indicator species by comparing the frequencies of the various species in different habitats.This method was tested with a real case using forest litter arthropods as a bio- indicator to evaluate rain forest health.Finally,the problems in using forest litter arthropods to evaluate and monitor forest habitat health are discussed and the use of multiple bio-indicator species in order to establish a balanced index system is recommended.
Evaluation of Surface Water Quality in Forest Catchment Based on Euclidean Distance Model with Varying Weights The Euclidean distance model with varying weights was applied to evaluate the surface water quality based on the monitoring data derived from April 2010 to February 2011 in secondary forest catchment,eucalypt plantation catchment and rubber plantation catchment in Limu Mountain,Hainan Island.The results were compared with that of grey association analysis method,grey clustering model and fuzzy comprehensive evaluation method.The results indicated that the assessment results of surface water quality in the three types of forest catchments based on Euclidean distance model with varying weights and grey clustering model were GradeⅠ,the assessment results of surface water quality in secondary forest catchment based on grey association analysis method and fuzzy comprehensive evaluation method were also GradeⅠ,but besides that the assessment results of surface water quality in eucalypt plantation catchment in June 2010 and rubber plantation catchment in August 2010 based on the last two methods were GradeⅡ,those in the remain seven months were GradeⅠ,showing that the plantation in this area did not cause significantly negative effect on surface water.
Review on Factors Affecting Plant Competition The competition refers to the interactions of two or more individuals which compete for resources,and is a key process of plant populations and communities.A comprehensive understanding of plant competition is necessary to predict the responses of ecological systems to environmental changes.The inside factors affecting competition include plant density,biological factors and the biomass.The environmental factors related to competition include light,soil moisture,soil nutrient and altitude.High density affects plant competition by controlling plant growth.Allelochemicals produced by plants directly affect their neighbors. Trees and grasses may compete for resources where their root systems overlap.Herbivorous animals chose to eat some plants,resulting in reduction of competition ability of the plants.Plants make morphological shifts and alter the competitive ability between above-ground and below-ground parts in response to the environmental changes.When shade- tolerant species are absent in mixed forest,less shade tolerant species could maintain their dominance for a long period.In contrast,mixed forest with tolerant species would reduce the dominance of less-tolerant species,maintain and probably increase the dominance through the decline of less-tolerant species.Smaller plants should have longer survival time due to their smaller total water requirements when water is scarce,and the longer survival of plants with higher root allocation could be due to a relative reduction in transpiring surface per unit root length.In nutrient-deficient soils,plants are stressed directly by the lack of adequate nutrients and competitive interactions may be controlled by a plant’s ability to efficiently take up available nutrients.In nutrient-sufficient soils,plants with the highest maximum growth rates may well be the superior competitors.Intensity of light competition declines with altitude.The future research about competition will focus on large scale,long term and multi-po...Spatial Para Allocation of a Small Watershed Protection Forest System With the interpreted IKONOS4 satellite images collected in 2005,a 1:10 000 forest map,the data collected in ClassⅡforest survey in 2007,and surface runoff data obtained in the permanent runoff monitoring station,six site factors of slope gradient, slope position,soil thickness,soil thickness of A layer,soil type and soil water content were selected to establish a matter element model suitable to 297 forest sub-compartments.Further,the AHP was applied to modify the spatial structure and form the spatial para allocation of the protection forest system. The results showed that:1) the area allocation of different vegetation types was irrational,the area of a mixed coniferous and broad-leafed forest was 124.39 ha,accounting for 14.97%of the forested land,the mixed forest was consisted of two coniferous species accounted for 27.37%of the total forest land,and the pure forest was consisted of one coniferous species accounted for 42.48%.2) After optimization,the area allocation of different vegetation types in the protection forest system ranked as:the mixed coniferous and broad-leafed forest(31.12%)>shrub land(15.5%)>the economic tree crops(12.28%)>the mixed forest consisting of two coniferous species(11.46%)>the pure broad-leafed forest(11.41%)>the pure coniferous forest(9.51%)>grass land(8.70%). Besides,the annual surface runoff could reduce 43 171 mm or 62.15%,annual soil erosion could decrease 465.97 t or 79.66%.3) The following suggestions for spatial para allocation of the small watershed protection forest system were proposed: (1) Reducing pure cypress or pine forest,and increasing alder-cypress,oak-cypress or pine-cypress mixed forest.As for the current cypress and pine pure forests,alder or oak could be introduced to develop a mixed forest.(2) The canopy closure of pure cypress forest and alder-cypress forests should be maintained within 0.60-0.75,and the canopy closure of oak-cypress,pine-cypress or oak-pine forests should be controlled with...Effects of Organic Calcium Made by Bamboo Vinegar on Growth of Cymbidium ensifolium and Soil Property The bamboo vinegar was used to produce organic calcium,and different concentrations of NaCl,CaCb and organic calcium solutions as deicer were sprayed evenly on the potted Cymbidium ensifoiium and collected soil, and the growth of C.ensifoiium was observed everyday,and the physical and chemical properties of soil were analyzed.The results indicate that all the 3 types of salt solutions had certain influence on C.ensifolium,while the organic calcium had less effect on C.ensifolium than NaCl and CaCl2,and both of NaCl and CaCl2 had little effect on the pH of soil while organic calcium increased greatly the pH of soil,and the organic matter and cationic exchange capacity of soil reduced,and the content of total N, P in soil also reduced while the apparent content of total K in soil increased.By above comparison,the effect of organic calcium made by bamboo vinegar on C.ensifolium and soil was less than that of NaCl and CaCl2,in addition smaller the concentration of salt solution was,less the effect of salt solution on C.ensifoliumand soil was.
Effects of Seasonal Freeze-Thaw Cycles on Quantity of Soil Microbes in Subalpine Fir Forest Fir(Abies faxoniana) distributes widely in the alpine and subalpine region of western Sichuan.To understand effects of freeze-thaw events on soil microbial community,microbial number was investigated monthly in a fir forest,employing the method of lab freeze/thaw cycles in combination with field soil sampling.Bacterial and actinomycete number in soil decreased and fungal count increased after a seasonal freeze-thaw season cycle.Bacterial and fungal counts increased with the decreased altitude,while actinomycete count decreased with the decreased altitude.Different microbes had various change patterns with altitude in humus layer(AL), illuvial layer(BL) and parent material layer(CL). Compared with the 3 582 m altitude,bacterial count in the AL and CL at the 3 298 m altitude increased 4.2%and 7.0%,respectively,but that in the BL decreased 0.6%.Meanwhile,bacterial count increased 11.5%,3.5%and 2.1%in the AL,BL and CL at the 3 023 m altitude in comparison with the 3 298 m altitude,respectively.Fungi count in the AL,BL and CL increased by 10.5%,10.3%and 16.4%at the 3 298 m altitude in comparison with 3 582 m altitude,respectively,while it increased by 2.4%,1.7%and 3.5%at the 3 023 m altitude in comparison with 3 298 m altitude,respectively. Actinomycete count in the AL at the 3 298 m altitude increased by 0.7%than that at the 3 582 m altitude, but decreased 5.9%and 13.9%in the BL and CL.In the AL and BL,it increased 5.2%and 5.2% respectively at the 3 023 m altitude than that at the 3 298 m altitude,while in the CL it decreased 12.4%.These results were in agreement with the simulation freeze/thaw cycle experiment in lab.The results also revealed that the seasonal freeze-thaw cycle increased the ratio of soil fungi to bacteria. These results demonstrated that different microbial groups responded differentially to the seasonal freeze-thaw cycle,which may be an important ecological mechanism for maintaining the seasonal frozen ecosystem.
Short-term Effects of Nitrogen Deposition on Soil Respiration of Cinnamomum camphora Plantation The nitrogen deposition experiments on Cinnamomum camphora plantation of Hunan provincial botanical garden were simulated from June the 7th to October the 7th,2010,the nitrogen deposition levels was respectively as control(CK, 0 g·m-2 a-1),low nitrogen(LN,5 g·m-2 a-1),medium nitrogen(MN,15 g·m-2 a-1) and high nitrogen(HN, 30 g·m -2 a-1).The soil respiration speed and soil surface temperature and the surface water content of the soil were determined by LI-8100 measuring instrument.The results show that the average values of soil respiration speed were CK (4.09±0.66μmol·m-2 s-1),LN(2.39±029μmol·m-2 s-1), MN(2.18±0.19μmol·m-2s-1),HN (2.28±0.25μmol·m-2 s-1),and the treatment of the CK was obviously higher than the other three treatments（P<0.01）.With different nitrogen concentrations deposition treatments,the Q10 （temperature sensitivity coefficients） for soil respiration of CK,LN,MN and HN treatments were 1.84,1.71,1.83 and 1.56.It was positive correlation between the respiration speed and the surface（≤10 cm） temperature of tested soil.It was negative correlation between the respiration speed and the surface（≤5 cm） water content of tested soil（P>0.05）.Volumetric water content of 5-cm soil was between 0.266 6-0.294 4(m3·m-3), and the monthly content did not vary too much during the research period（1.8%-9.4%）.The findings suggest that the initial stage of nitrogen deposition obviously influenced the soil respiration of C.camphora plantation.
Review on Leaf Water Use Efficiency of Major Trees Species in Arid and Semi-Arid Area The tree specie selection is the critical part in the process of vegetation restoration and reconstruction in arid and semi-arid areas.As a reliable indicator of drought resistance and water use characteristics of tree species,water use efficiency（WUE） has become a hotspot in the research on tree specie selection.This paper introduced the concept and correspondingly research method of leaf WUE and summarized the research progress of leaf WUE in terms of the variation in leaf WUE between species,positions in the canopy,and characteristics of temporal and spatial variation,its influence on environmental factors like illumination,moisture,temperature, CO2 and O3 concentrations.Furthermore,it put forward the problems currently existing in the research and prospected the trend of future research on leaf WUE.
Construction of an Evaluation Index System on Forest Soundscape By drawing on studies of domestic and international forest landscape assessment and visual evaluation of urban soundscape,we summarized the main factors affecting the forest soundscape.On this basis,we established an evaluation system for level 2 class 3 forest soundscape.Eleven indicators of the forest sound landscape aesthetic evaluation system and the weight of the product were scored, and then the accumulated scored values were defined as the sound landscape aesthetic index.The acoustic landscape index was used to measure the size of the forest landscape beautiful degree.
Physiological Responses of Mangroves to Flooding and Anaerobic Stress Flooding and anaerobic stress is one of the stress factors affecting mangroves.Mangrove species,differing considerably in their susceptibility to the stress,are distributed in different tidal elevation zones.Growing in regular seawater dipping and anoxic mud,mangroves have developed a set of adaptation mechanisms of flooding and anaerobic stress.This paper emphatically reviewed four physiological responses of mangroves to flooding and anaerobic stress,i.e.nutrition allocation, photosynthesis and respiration,carbon and nitrogen metabolism and antioxidant mechanism.Finally,it was proposed that studies should be further focused on the path of roots metabolism,non-structure carbohydrates and secondary metabolism of the mangroves under flooding and anaerobic condition.
Path Selection for Forest Carbon Market Cultivation in China With the analysis on the characteristics of global forest carbon market in 2010 and based on the current status of China’s forest carbon market, the paper presented the path selection for forest carbon market cultivation in China,i.e.strengthening the promotion and cooperation of international forest carbon sequestration projects to forward global forest carbon market development,developing primary market transactions to steadily promote financial market development,promoting the formation of domestic forest carbon market,and putting voluntary emission reduction as the priority of current market development.
Spatio-temporal Variation of Distribution Patterns in Cunninghamia lanceolata Plantations To aid in management of Cunninghamia lanceolata,the main timber species in Southern China,its variation of spatial distribution pattern was analyzed.Three permanent plots of C.lanceolata plantations with approximately the same site conditions,set by China continuous forest inventory in Shunchang,Fujian,were selected. C.lanceolata growth was divided into two stages: young trees(5 cm≤diameter at breast height (DBH)<10 cm) and mature trees(DBH≥10 cm). The DBH and coordinates of every tree(DBH≥5 cm) in the permanent plots were recorded in 2003 and 2008.The function L(r),improvement of Ripley’s K(r),the paircorrelation function g(r),and the uniform angle index(W_i) were used to analyze the spatio-temporal variation of spatial distribution patterns.The three permanent plots had mean uniform angle index(W) between 0.494-0.578 at low altitudes,0.465-0.477 at medium altitudes,and 0.426-0.601 at high altitudes.Results showed that altitude did not affect the spatial distribution pattern. The L(r ) and g(r) function curves of mature trees were generally lower than young trees’,i.e.tend to be more random or uniform distribution.So regardless of the initial distribution of young or mature trees,with the passage of time,there was a tendency for the aggregated distribution to change to a random distribution,and a random distribution to change to a uniform distribution.
Comparison and Dynamic Calibration between LAI Values of Larix principis-rupprechtii Plantation Determined by Canopy Scanner and Litter-fall Collection In order to test the accuracy of the usually-used fixed calibration factor of the canopy scanner of LAI-2000 for measuring the leaf area index(LAI),a Larix principis-rupprechtii plantation was chosen in the small watershed of Xiangshuihe located at the Liupan Mountains of Ningxia Hui Autonomous Region of NW China,the LAI was measured in October 2010,a period from full canopy to the total fall of needles,by using both the LAI- 2000 and litterfall collection method.Then,a comparison was made between the LAI values determined by the litter-fall collection and that calculated based on the figures read from LAI-2000 and the fixed calibration factor(1.49).It showed that the average of LAI measurements of the 2 methods was very close,with a difference of only 5%.However,the calculated LAI from LAI-2000 was obviously higher than the true values determined by litter-fall collection when the canopy was full of needles;and obviously lower than the true value when the canopy was sparse after needle falling.The reason may be that LAI-2000 takes the projection of twigs as needles.So,a dynamic calibration factor is needed,especially in the seasons when the needle amount and the percentage of twigs projection in crown projection change quickly.Therefore,a statistic relation in a quadratic polynomial form between the 2 series of LAI data was well fitted. This relation can be used for a more accurate estimation of LAI based on the data read from the easilyused canopy scanners like LAI-2000.
Quantitative Evaluation of Conservation Priority of Endangered Plants in Northeast China By adopting the evaluation index system of conservation priority which included threatened coefficient,genetic coefficient,utilization coefficient, protection status coefficient and list status coefficient,the endangered plants in Northeast China were quantitatively analyzed and synthetically evaluated,and the value of conservation priority and conservation priority grades of the endangered plants were determined.The results showed that there were 60 species of endangered plants belonging to 42 genera and 25 families in Northeast China,the value of conservation priority ranged from 0.853 8-0.318 4.The endangered plants were divided into 3 grades according to their values of conservation priority, 17 species belonging to 15 genera and 11 families were in the first grade protection,18 species belonging to 14 genera and 11 families were in the second grade protection,25 species belonging to 17 genera and 13 families were in the third grade protection.The quantitatively evaluation index system of conservation priority in this paper represented the degree of conservation priority of the endangered plants comprehensively,objectively and accurately.
Response of Stream Water Chemistry to Rainwater Acidification in Natural Forest Region of Qinling Mountains This study was conducted in the Huoditang naturally-regenerated forest,which is located at the center of the natural forest region across the southern-slope of the Qinling Mountains. Rainwater and stream water samples were collected mainly in rainy seasons in the area.The sample pH values and chemical concentrations were measured. The response of stream water chemistry to rainwater acidification in the region was studied.The results showed that long time rainwater acidification could result in reduction of pH value,Ca2+ and Mg2+ concentration in the stream water.The changes of K+,Na+ concentration of stream water were not correlated with the rainwater acidification.There was no response of Zn,Pb and Cd concentration of the stream water to rainwater acidification.The acidified rainwater did not result in the release of the heavy metals enriched in the forest soil.
Phytoremediation Characteristics of Pb and Cd Contaminated Soils by Ginkgo Seedling In this article,we investigated effects of lead and cadmium on the biomass of ginkgo seedlings, and roles of the seedlings in accumulation characteristics of the heavy metals and remediation of the soil contaminated by Cd2+ or Pb2+ as well as their combination.The results showed that both Cd2+ and Pb2+ significantly or very significantly reduced biomass increment of ginkgo seedlings,with Pb2+ more adverse than Cd2+.The Cd2+-Pb2+ compound pollution further reduced biomass increment of ginkgo seedlings.The mass fractions and enrichment coefficient of Pb2+ and Cd2+ in ginkgo seedlings were in an order of root>stem>leaf,which was in favor of transportation Pb2+ and Cd2+ from root to stem and leave.The Cd2+-Pb2+ compound pollution promoted ginkgo seedling absorption to Cd2+ and Pb2+.The capacity of the upward transport of Pb2+ was greater than that of Cd2+,which suggested an obvious dose-effect and synergistic effect.Cd2+ and Pb2+ accumulations in ginkgo seedlings were relatively large.The accumulation in roots was higher than that in stems and leaves.The ability of the absorption,transportation and accumulation of ginkgo seedlings to Pb2+ was relatively greater under Cd2+-Pb2+ compound pollution.The phytoremediation efficiency of Cd2+ and Pb2+ was relatively high.
Ecological Environment Change in North Slope of Qilianshan Mountains Based on meteorological,hydrological, forest,and grassland data collected by location observation,remote sensing,field surveys and relevant literature during 1956 to 2009,the ecological environment change in northern slope of the Qilianshan Mountains was analyzed synthetically using regression and correlation analyses.The results showed that the temperature had an annual variation rate of 0.033 4℃·a-1 in northern slope of the Qilianshan Mountains since 1960,and exhibited a raising trend,especially since 1987.The annual variation rate of annual precipitation was 0.570 2 mm·a-1,indicating that the precipitation tended to increase.The climate had changed from arid to humid in this region since 1976.From 1956 to 2006,the glacier area of six inland river basin（Shiyanghe river,Heihe river, Beidahe river,Shulehe river,Danghe river and Halternhe river） and Datonghe river basin in northern slope of Qilianshan mountains decreased by 17.7%. Thickness of the glacier reduced about 5-20 m,and the snow line rose about 100-140 m.The Glacier ice reserves in inland river basin of Hexi decreased by 11.4%.From 1972 to 2007,27 glaciers in the eastern section of the Qilianshan Mountains disappeared.From 1956 to 2009,the runoff change in the northern slope of the Qilianshan Mountains was different in different regions.The runoff was reduced significantly in Shiyanghe river basin, increased slightly in Heihe river basin,and increased obviously in Shulehe river basin.From 1958 to 1988, the area of deforestation and farming was more than 10.0 million ha,and the forest area was reduced 0.6 million ha.Since the Qilianshan Mountain Nature Reserve was established in 1989, the forest was restoring gradually because of continual protection and cultivating,and the forest area was increased 9.4 million ha from 1989 to 2008. Due to human interference,especially over-grazing impact,the quality of the wood-land,shrub-land and grass-land in northern slope of the Qilianshan Moun...Research Advances in Effect of Nitrogen Deposition on Forest Carbon Sequestration Nitrogen deposition imposes important impact on the function and the stability of forest carbon sequestration.This paper reviewed the research advances in the increasing response of forest carbon sequestration to nitiogen deposition, described the application prospects of stable carbon isotope technique in the research field.And finally this paper pointed out that,on the condition that nitrogen deposition rises,on the allocation of forest photosynthetic products and the change in soil carbon turnover rate are the two hotspots in the future carbon cycling research.
Influencing Factors of Fine Root Production and Turnover in Forest Ecosystem Fine roots（≤2mm in diameter） play important roles in carbon balance and nutrient recycling in forest ecosystem.With the development of the study on global carbon cycle,fine roots have attracted considerable attention as the main source of soil carbon in forest ecosystem.On the basis of synthetic analysis of research reports in domestic and foreign literatures,we summarized and elaborated the major abiotic and biotic factors that control fine root production and turnover.The environmental factors included soil nutrient,soil temperature,soil moisture and the CO2 concentration.Soil organisms,fine root morphology and forest stand characteristics were discussed as biotic factors in this paper.Finally,we defined the problems arising in root system research and prospected the future research direction.
Effects of Different Nitrogen Sources on Transformation and Availability of Inorganic Phosphorus in Root-Soil Interface of Pinus thunbergii Seedlings The calcareous fluvo-aquic soil was collected and a microcosm study was carried out with root-mat and frozenslicing method in laboratory. The pH in the root-soil interface with the control treatment was just slightly lower than in the bulk soil.However,the addition of NH4- -N significantly decreased the pH value in the root-soil interface and the addition of No3 -N slightly increased the pH value in the root-soil interface.The magnitude of pH changes in the root-soil interface depended upon the concentrations of the nitrogen sources added.The contents of Ca2-P,Fe-P and Al-P in the root-soil interface were much lower after treated with NH4 -N and slightly higher after treated with No3 -N compared with control treatment.After treated with 100,200 and 400 mg·kg-1NH4+ -N,the deficiency rates of Ca2-P in the area 0-1 mm from the root plane were 37.1%,45.9%and 57.7%,respectively,the deficiency rates of Fe-P were 23.4%,29.1%and 38.2%,respectively,and the deficiency rates of Al-P were 25.1%,28.0%and 33.2%,respectively. Compared with the control the deficiency rates of Ca8-P in NH4+ -N and No3-N treatments decreased and increased,respectively,but the differences were not obvious.The contents of Ca10 -P and O-P in the root-soil interface did not significantly change after treated with NH4+ -N or No3 -N,suggesting that Ca10- P and O-P were remarkably difficult to be mobilized even at the presence of high concentration of NH4+ -N.The lowered pH in the root-soil interface induced by the addition of the NH4 -N promoted the transformation of phosphates in the root-soil interface,enhanced the mobilization and bioavailability of phosphates,and thereby remarkably increased the absorption of phosphorus by roots.
Classification of Tomicus Species Both morphological characters and a portion of of 28S rDNA sequences were used to identifying Tomicus species.The specimens were classed into groups with the following characters: 1) granules or punctures on interstria 2 on the declivity of the elytra;2) length of the elytral interstrial hairs and hairs arising from punctures;3) arrangement of pronotal punctures and hairs.These characters could be clearly examined under a binocular microscope at 30×magnification and they were applicable and valuable for the forest entomologists to identify Tomicus species.The phylogenetic tree established with difference in 28S rDNA sequence of D2 region revealed that the specimens of each group identified by morphological characters were also grouped together.The genetic distances of intra-species, inter-species and inter-genus were not overlapped. Genetic divergence of 28S rDNA was also useful for identifying Tomicus species.
Review of Studies on Structural Features,Regeneration Features and Management of Natural Spruce-Fir Mixed Stand of Coniferous and Broadleaved Trees in China Natural spruce-fir mixed stand is one of the main forest types in the world,and also has huge ecological,economic and social benefits.According to the structural characteristics and succession laws of natural spruce-fir forest,it is urgent and significant to develop scientific management measures for natural spruce-fir mixed stand in line with local conditions.The article outlined the characteristics of the distribution and structure, regeneration and succession laws of natural spruce-fir forest,and analyzed the current situation and existing problems of natural spruce-fir forest management.The following recommendations were eventually made:1) In no cutting area,all logging activities should be banned.In a restricted cutting area,the cutting intensity should be generally controlled within 15%of the stock volume before cutting.On the commodity forest management area, the appropriate cutting intensity should be determined according to the volume per hectare,determine and classification management should be implemented in accordance with the characteristics of forest,to ensure the scientific selective cutting.2) Closure for afforestation,planting and repair planting should be adopted on vegetation-intensive land,sparse shrubs covered land and harvesting slash,in order to accelerate natural regeneration.3) The in situ conservation should be conducted in nature reserves and scientific experiment stations of rare and endangered species,such as Abies chensiensis,Picea neoveitchii,Abies vuanbaoshanensis,to reduce human destruction.4) It is supposed to collect seeds in time,establish nursery,actively establish forest, expand artificial population and promote natural regeneration.
Soil Particle Composition and Its Relationship with Nutrient Contents in a Quercus aquifolioides Forest at Different Altitudinal Gradient The current research focuses on soil particle separate and total organic carbon and nitrogen in Quercus aquifolioides forest in Balangshan,Wolong Natural Reserve,Sichuan,and their correlation at tree altitudinal gradient.The result shows that:The soil particle separate of Q. quifolioides forest is mainly of silts,and the soil texture is medium textured soils;The contents of soil total organic carbon content and nitrogen content in 0-15 cm layer are higher than that in 15-30 cm layer in different attitude gradients;the total organic carbon content in the topsoil shows a low-high-low tendency at different altitudinal gradients,whereas that of the subsoil shows a growing tendency;The C/N ratio of Q.aquifolioides forest is relatively small,with an average of 12.77;The correlation analysis between the soil total organic carbon and nitrogen content and soil particle separate respectively tells us:contents of soil organic carbon is very significantly positively correlated with total nitrogen in the two soil layers(P<0.01) at 3 549 m,no correlation at 2 551 m;the contents of total organic carbon and nitrogen are very significantly positively respective respectively with coarse silt content in 0-15 cm and 15-30 cm soil layers(P<0.05),but negatively with clay in different layers(P<0.05) in 0-15 cm soil layer at 3 549 m,significantly positively(P<0.05) and very significantly positively correlated(P<0.01) respectively with coarse silt content in different soil layers at 3 091 m,very significantly and significantly positively correlated respectively with fine sand content in different soil layers at 2 551 m,but negatively with fine silt content in 15-30 cm soil layer.Finally,in this paper the results presented that relationships among soil particle separate and total organic carbon and nitrogen content are quite complications in Q.aquifolioides forest at different altitudinal gradient.
Changes in Contents of N,P,K,pH and Organic Matter of Soil Experiencing Hydro-Fluctuation in Three Gorges Reservoir Setting monitoring transect in the middle and shallow water area(altitude 156-172 m) in Three Gorges reservoir hydro-fluctuation belt to research the changing characteristics of the contents of N, P,K,pH and organic matter of the soil which experienced the influence of fluctuation the first time. The results showed that by the influence of water level fluctuating,contents of soil N,P,K,pH and organic matter had reduced in different soil layers in hydro-fluctuation belt.The available N decreased by 41.53%-59.87%,available P decreased by 5.26%- 36.76%,available K decreased by 3.55%-45.56%, total N decreased by 9.52%-40.00%,total P had no change generally,total K had decreased a little, content of organic material decreased by 7.62%- 37.83%%,pH value turned to neutral,changed by 1.73%-9.58%.
Cloning and Expression of Two MYB Transcription Factors in Tea Plant(Camellia sinensis) MYB transcription factors represent a family of genes that include the conserved MYB DNA-binding domain,and they are widely involved in the regulation of plant development and secondary metabolism.In this study,Part of sequences of two MYB transcription factors was determined through the cDNA microarray hybridization and selection of cDNA library derived from tender shoots.The full-length cDNAs of the genes were obtained with RT-PCR and RACE,and they were 1 132 bp and 1 020 bp,named as CsMYB1 and CsMYB2 (GenBank accession No.HQ660373 and HQ660374), and contained ORFs of 879 bp and 675 bp encoding 292 and 224 amino acids,respectively.Sequences analysis showed that the deduced protein molecular weight of the two genes were 32.9 ku and 25.4 ku, and the proteins contained two conserved MYB domains near the N-terminus and a conserved C1 motif near the R3 domains.The deduced amino acid sequence of CsMYB1 and CsMYB2 from tea plant showed high identity with that of other plants,for instance CsMYB1 shared 57%homology with MYB1 of Gossypium hirsutum and CsMYB2 shared 75% homology with MYBC2 of Vitis vinifera.The result of real time-PCR analysis showed the two genes were expressed constitutively in all tissues with different expression levels,e.g.the relative expression level of CsMYB2 in leaf was hundred times higher than that in root.Additionally,shading enhanced CsMYB1 expression,while the treatment did not alter the expression level of CsMYB2.
Relationship between Geographical Distribution of Pinus yunnanensis and Climate A distribution map of Pinus yunnanensis was made according to the data on geographical distribution of P.yunnanensis by means of applying geographic information systems software ArcGIS, and the climatic parameters of the distribution areas for P.yunnanensis were determined by the climate forecast model Climate China.The relationship between the geographical distribution of P.yunnanensis and the climate was studied by adopting the indexes of Kira including the warmth index(WI),coldness index(CI) and aridity index (K),Xu’s humidity index(HI),Holdridge’s life temperature(BT),potential evapotranspiration (PET),potential evapotranspiration ratio(PER) and the single factors as the mean annual temperature, the mean temperature in January,the mean temperature in July,the mean annual precipitation, the>5℃accumulated temperature,the>18℃accumulated temperature,the maximum temperature, the minimum temperature,the temperature variation, the ratio of temperature and precipitation of the year, etc.And the Kira’s water-temperature indexes on distributional upper limit,low limit and north limit were discussed.The major climatic factors effecting the distribution of P.yunnanensis were screened out by statistical analysis software SPSS and the results showed the impact factors are in the order of temperature>humidity>the temperature difference between mean warmest month temperature and mean coldest month temperature.
Prospect of Evaluation Study on Vegetation Degradation Vegetation degradation is related to the stability and succession process of ecological systems.This paper combed and screened the recent national and international research on vegetation degradation,and discussed vegetation degradation research in terms of selection of reference ecosystem for evaluation,selection of evaluation index system and the selection of evaluation methods.At last,the direction of vegetation degradation research was predicted and prospected.
Research Advance in Construction of Forest Genetic Linkage Map Forest genetic maps are an important component within the forest biologist’s toolkit, underpinning forest improvement programs.The estimation of forest genetic maps is a conceptually simple yet computationally complex problem,due to long growth period and high heterozygosis and genetic load of forest trees.At present,some genetic maps of trees have been constructed.This paper reviewed the process of forest genetic map construction,highlighting its uniqueness,and pointed out the problems that might rise in mapping.Finally, prospect was made for constructing the high density genetic map of trees.
Application of Molecular Marking Technologies in Heredity Breeding of Eucalyptus Eucalyptus is an important tree species on the global scale,and also it is the model tree in forest genetic research.Therefore,the research and application of molecular marking technology in heredity breeding of Eucalyptus have important theoretical significance and practical value.This paper described several major molecular marker technologies and their application to heredity breeding of Eucalyptus,and prospected the future application and study of these technologies.
Clonal Variation in Growth and Wood Quality and the Multi-Trait Index Selection of Chinese Fir Two clonal trial stands of Chinese Fir （Cunninghamia lanceolata） were used in this study, one was 19-year-old stand which included 38 clones, and the other was 17-year-old stand including 102 clones.The statistical analyses showed that there were very significant genetic variations in height, DBH,volume and ratio of heartwood(Rhw),wood basic density（ρb ） of the clones in the two stands. The repeatability of clones was in median to high level,and the genetic CV was different over the all five traits.There were very significant phenotypic and genetic correlations among height,DBH and volume,and negative correlations among growth, Rhw andρb.The selection method experiment indicated that index selection could improve volume, Rhw andρb,showing synthetically superior selection effects compared to any individual trait selection methods.
Effect of Spinosad on Detoxifying and Protective Enzymes of Malacosoma neustria testacea To study the insecticidal activity and toxicity mechanism of spinosad,we assayed bioactivity of spinosad by leaf membrane method and its effects on the activities of detoxifying and protective enzymes in Malacosoma neustria testacea larvae by spectrophotometry.The results showed that spinosad had an extremely high toxicity against the 4th and 5th instar larvae.The glutathione S-transfer (GST) activity in 4th and 5th instar larvae was firstly inhibited,then induced,and finally inhibited,while the mixed-functional oxidase(MFO) activity was inhibited and then enhanced.The induced effect on carboxylesterase(CarE),the induced and inhibited effect on acetylcholinesterase (AchE) and peroxidase(POD),and the complicated effects on superoxide dismutase(SOD) and Catalase(CAT) were determined in 4th instar larvae with spinosad treatment.However,the obvious inhibition effects were found on the activities of CarE,AchE,SOD and POD in the 5th instar larvae whereas the catalase(CAT) activity was inhibited, then increased,and inhibited finally.Therefore, spinosad could effectively disrupt and interfere not only the detoxifying and protective enzymes but also normal physiological metabolism of M.neustria testacea and show extremely high toxicity against this pest.
Cloning and Bioimformatic Analysis of Cellulose Synthase-like Protein Gene,CICsID1 from Cunninghamia lanceolata The protein structure of the cellulose synthase-like protein(CSL) was similar to cellulose synthase(CesA),including the conservative sequence D,D,D,QXXRW.One full-length cDNA of the cellulose synthase-like protein D(CslD) gene was cloned by reverse transcriptase(RT)-polymerase chain reaction(PCR) with 5’,3’ rapid amplification of cDNA ends(RACE) methods using degenerate primers designed from the homologous sequences of the CesA genes.A multiple comparison sequence analysis was conducted concurrently with bioinformatic methods to analyze the obtained sequence.Results of the sequence analysis showed that this cDNA was 4 150 bp in length and contained a single open reading frame encoding a protein of 1 132 amino acids.The multiple comparison sequence analysis showed that the deduced amino acid sequence shared high similarity (over 71%) with the ClCslD genes from Populus tremuloides,Oryza sativa,and Arabidopsis thaliana. This work will help lay an important foundation for further molecular studies with cellulose synthesis of plants.
Study on Storage and Bourgeoning of Spruce Pollen The effects of sucrose concentration,pH value and storage conditions on germination and pollen tube growth of in vitro cultured spruce were studied and the ingredients of culture medium were optimized.The results showed that the effect of sucrose concentration and pH value on spruce pollen’s germination was significant,and a clear threshold effect existed.Low or high concentration of sucrose was not conducive to the pollen’s germination,it was found that 10%of which was more suitable to the in vitro culture of spruce pollen; different spruce species required different concentrations of sucrose medium,7.5%of sucrose concentration medium was better to pollen tube germination of Picea asperata,but 10%of which was the best medium to that of Picea abies.Both pH 4.5 and 6.5 had restrained action on pollen germinating rate of spruce,and the growth of pollen tubes.Under dark culture conditions,P.abies began to germinate in 6 h,but P.asperata germinated in 8 h,the mass germinating power of P.abies was higher than that of P.asperata;the growth process of P.abies was 20-22 h,and that of P.asperata was about 16 h;The pollen tubes of P.abies was over 10 ?m longer in length than that of P.asperata. There were significant differences of germinating power and length of pollen tubes between genotypes of two different individuals of both spruces.The storage methods had great influence on the viability of pollen.In the process of pollen preservation, temperature was the key factor.Cryopreservation was better than cold storage and room temperature preservation was unfavorable.
Absorption and Accumulation of Heavy Metal from Soil by Leaves of Populus x euramericana cv.‘Neva’Plantation The absorption and enrichment of heavy metal elements by leaves of Populus×euramericana cv.’Neva’ were analyzed through content assessing of heavy metal elements in soils of three forest lands at Fangshan District in the southern suburb of Beijing. These forest lands with P.×euramericana cv. ’Neva’plantation were around with the various sources of pollution such as cement mill,stone mill, sewage and garbage.Some of heavy metal elements such as Cd,Pb,Cu,and Zn were found in the soil samples and leaves of P.×euramericana cv.’Neva’ grown on the three forest lands which were investigated.The results of investigation showed that the soils of three forest lands were polluted with Pb, Cd,Cu and Zn in varying degrees.The contents of Pb,Cu and Zn in soils were significantly different among the three forest lands,whereas the average content of Cd(0.077 6 mg·kg-1) was less but that of Pb,Cu,and Zn(37.61,26.25 and 90.3 mg·kg-1 ) were more than the average background value of Beijing.The contents of Pb,Cd,Cu and Zn in leaves of P.×euramericana cv.’Neva’ were different among three forestlands.With the changes of heavy metal contents in soil samples,there was no regularity on the changes of different heavy metal contents in leaves of P.×euramericana cv.’Neva’ grown on different forest land.P.×euramericana cv.’Neva’ can absorb and accumulate Pb,Cd,Cu and Zn in soil but showed different capacities of absorption and accumulation with the order of Cd>Zn>Cu>Pb.Especially,its absorption and accumulation capacity for Cd was strong with maximum enrichment factor higher than 16 and showed high accumulation on low background,whereas its enrichment capacities for Pb and Cu were relatively poorer with average enrichment factor of less than 1.At different forest lands,there existed great difference on absorption capacity of P.×euramericana cv.’Neva’ with the same heavy metal.
Research Progress of Mechanism of Heterosis in Plant Heterosis is the universal phenomena in nature,and its formation mechanism has been the focus of research.On this basis,a number of theoretical hypotheses have been proposed for the reason of heterosis,such as the dominance hypothesis,epistatic effect,gene regulation networks,etc.For the past years,many researchers have attempted to elaborate the mechanism of heterosis at physiological & biochemical level and molecular level.The results showed heterosis plants have a stronger photosynthetic capacity,relatively well-developed tissues and greater adaption and buffering ability to external environment.The heterosis is often more pronounced in relatively low light,low temperature and low CO2 concentration. In addition,genetic distance,differences in gene expression and DNA methylation are all closely related with heterosis.This study reviewed research results of forestry and agriculture,and discussed the future research direction of this field.
Genetic Diversity and Mating System Analysis of Pinus massoniana in Second-Generation Clonal Seed Orchard A total 61 clone parents and 320 open-pollination progenies from 8 clone individuals were identified by 12 polymorphic SSR loci.The result showed that the level of genetic diversity in progeny population was the same as in maternal population, progeny population had all alleles detected in maternal population,and there were not obvious surplus phenomenon of homozygotes in progeny population (F= 0.046).The south crown had more strobili than the north crown,however the genetic diversity of the north crown strobili was not substantially reduced.The progeny of neutral trees had the same level of genetic diversity as in the progeny of partial female trees,with the fixation index tended to be zero,which was accorded with Hardy-Weinberg equilibrium.The multilocus outcrossing rate in the seed orchard was 1.097,and there was no significant inbreeding between parents(t_m-t_s= - 0.031).The multilocus outcrossing rate and singlelocus outcrossing rate in the south crown were higher than that in the north crown.The multilocus outcrossing rate of partial female trees was the same as in neutral trees,and the neutral tree had no obvious declining outcrossing rate with reduced proportion of female and male strobilus compared with partial female tree, with the fixation index tended to be zero.The progeny of the second generation clonal seed orchard still had rich genetic diversity,gene exchange among clones was relatively sufficient,and biparental inbreeding was not significant.
Evaluating Natural Forest Management Efficiency According to the structure-based forest management theory,the appraisal indices system of natural forest management efficiency was established from spatial utilization,species diversity, constructive species competition and tree composition,which could be used to depict stand status,and its metewand was given.Relative weight was endowed by The Analytic Hierarchy Process (AHP),and then the conception of natural forest management efficiency comprehensive appraisal index was put forward for the first time and applied to four different sampling plots of natural forest, three of them from Dongdapo forest region,Jiaohe, Jilin province,and one from Baihua forest area, Xiaolongshan,Gansu province,China.The results are as following:the stand status was obviously improved after being managed and plot A,B got a mark of "medium" while C and D were "perfect". From high to low,the arrangement of forest management efficiency comprehensive appraisal index was C>D>A>B.This appraisal result abided by the phenomenon detected in the practical field.The forest management efficiency comprehensive appraisal index brought up in this paper could be taken as a way of comprehensive quantitative change of stand state which directly reflects the effort of forest management and affords scientific basis of natural forest management effort.
Differences in Growth and Physiological Characteristics in Different Growth Vigor Clones of Populus deltoids To investigate differences in physiological characteristics of growth and physiological basis of high growth vigor in the first generation of Populus deltoides which are from different growth vigor clones,here we chose two groups of seedlings with different growth vigor:high（A） and low（B）.Indexes of phenotype and physiology were successively measured to study the growth,photosynthesis and nutrient absorption.There were significant or very significant differences in dry mass of root,stem, leaf and the total biomass between A and B.Dry matter of roots had the smallest proportion in different components,and the largest proportion was stem in A,while the leaf had the largest proportion in B.Changes in growth and physiological characteristics showed a certain regularity during June to September.All clones grew the most rapidly and physiological characteristics varied the most significantly in July.Correlation analysis showed that seedling height and ground diameter were both significantly correlated to leaf area,night respiration rate,NH4- uptake rate and the total photosynthetic rate（R>0.826,P<0.05）,suggesting that the seedling growth was mainly affected by their own total photosynthetic capacity,nutrient absorption and night respiration consumption.In general,A was superior to B in all these factors,which construct physiological basis of the high growth vigor.
Establishment of Efficient Regeneration System of Populus×euramericana cl.‘Bofeng’ Compared with the species of Leuce section,the difficulty in plant regeneration during tissue culture for the species of Aigeiros section is a key limiting factor for their application in genetic engineering of forest trees.In this study,the plant growth regulators combination,copper concentration,light intensity,and the selection pressures of kanamycin were investigated using leaves of Populus×euramericana cl.’Bofeng’ as explants,and a stable and high efficient regeneration system was established.Using this system,both the shoot regeneration rate and rooting rate were up to 100%,and the average number of differentiated shoots in each leaf explant was up to 20,and the survival rate of seedlings reached 98%.The optimal selection pressure of kanamycin in shoot inducement for leaf-explant was 40 mg·L-1,and the optimal selection pressure of kanamycin in root inducement of adventitious bud was 20 mg·L-1.The authors also found that differentiation rate of adventitious buds of P.×euramericana cl.’Bofeng’ could be significantly promoted by increased copper concentration,and this is the first report about the key role of copper（Cu） in explant regeneration of Poplars.This regeneration system with high frequency which was established by the authors was as good as that of species of Leuce section,and it provides a good technological platform for genetic engineering of forest tree which uses the species of Aigeiros section as model materials.
Research Progress of Natural Regeneration Barrier of Forest After reviewing a large quantity of literatures at home and abroad,the natural regeneration barrier mechanisms of forest were described,including lack of seed,animal eating and trespass,plants allelopathy,microbial pathogenesis, unusual state of ecological factors like light, temperature,humidity and rainfall,physical obstruct of understory groundcover and litters,natural and human disturbance and difference forest community characteristics.The paper finally came up with the problems existing in the current research and the development idea of the research.
Aerial Image Information Extraction Based on Non-negative Matrix Factorization This study was on superiority of the non- negative matrix factorization（NMF） algorithm for application of information extracted with aerial images.First,NMF was used for aerial image information extraction,and then this data was compared with a principal component analysis（PCA） in which r（the number of rows or columns of basic matrix） and Eignum（the number of eigenvalues） were given different values.Experimental results showed that the run time of NMF with r = 20 or 50 was less than that of PCA with an Eignum = 20 or 50.Also,the recognition rate of NMF with r = 50 was higher than that of an Eignum = 50.The experiment showed that nonnegative matrix factorization had advantages of a short time period with a high recognition rate.
Precision Fire Hazard Divisions for Collective Forest in Southern China This paper focuses on how to build the model of precision fire hazard divisions in the level of forest resources sub-compartment.Based on 3D GIS technology and characteristics of forest fires in collective forest of southern China,this study utilized Lin’an City,Zhejiang Province as the experimental area.Forest fire factors were divided into 11 indexes from the three categories(social and economic factors,forestry characteristics,and meteorological characteristics) and weighted for analysis.Next,three eigenvectors(one for each category) were created to build a nonlinear mathematical model called precision fire hazard divisions for forests.Then,the model was used to optimize and test forest fire hazard divisions with the least squares.Results showed that experimental and theoretical values of error were less than 0.1. Thus,in the experimental area this model and the fire occurrence history matched.
Analysis of Basal Area for Chinese Fir Plantation Using Two Kinds of Nonlinear Mixed Effects Model(Two Levels) Nonlinear mixed effects model（NLMEM） is based on the relationship between the fixed and random effects in the regression function.The NLMEM has a competitive advantage in analyzing repeated measures data,the longitudinal data and multilevel data.This paper chose two kinds of two-level nonlinear mixed model to analyze basal area growth for Chinese Fir（Cunninghamia lanceolata）. Model 1 is a general two-level NLMEM and Model 2 is based on Model 1 to further consider the fixed effects parameters changes with a specific factor. Firstly,through the analysis of these two models, this paper defined the basic model to build the two-level NLMEM.Secondly,665 kinds of models derived from Model 1 and 2 703 kinds of models derived from Model 2 were calculated and compared. The results showed that:for Model 1,there were 57 kinds of models converging,and when the formal parameter b0 considered the block effects and plot effects,b1 and b4 only considered the block effects, the model fitted the best;and for Model 2,there were 24 kinds of model converging,and when the formal parameter bs considered the block effects and plot effects,b1 only considered block effects and the fixed effects b0 changed with any level of block level, Model 2 fitted the best.Finally,by comparing the traditional nonlinear regression model,Model 1 and Model 2,the results showed that Model 1 and Model 2 fitted better than the traditional nonlinear regression, and Model 2 was best fitting model.
Comparison on Estimation of Wood Biomass Using Forest Inventory Data Based on sixth and seventh national forestry inventory data of the six provinces,including Guangdong,Jiangxi,Guizhou,Shaanxi,Jilin and Beijing,the three methods(IPCC,continuous function for biomass expansion factor and weighted biomass regression model) were selected to estimate wood biomass in this paper.The estimation of the three methods were compared and analyzed from calculating process,method characters,repeatability and verifiability to stability of growth rate of biomass between two periods.The results showed the total biomass estimated by IPCC method with variable BEF2 was large,the total biomass estimated by IPCC method with constant BEF2 was small and the total biomasses estimated by continuous function for biomass expansion factor and weighted biomass regression model were middle.The biomass expansion factor derived from weighted regression model was most stable in the different provinces. Based on the seventh national forestry inventory data, the biomass expansion factors of various kinds of tree species derived from IPCC and the weighted regression model were more stable than the biomass expansion factors derived from continuous function method.The growth rate of biomass between two periods was the same regular pattern as the biomass expansion factors.
Modeling Branch Length and Branch Angle with Linear Mixed Effects for Dahurian Larch In this study,the sample data was based on 2 190 branch length and angle samples of 30 trees from dahurian larch（Larix gmeiinii） plantations located in Wuying Forest Bureau in Heilongjiang Province.The stepwise regression techniques were used to develop branch length and branch angle models:BL= b1 + b2 DINC + b3 DINC2 + b4 DBH·DINC2,BA = b1 + b2 DINC + b3 DINC2 + b4 DBH·DINC.Then,the developed models were fitted using linear mixed-effects modeling approach based on LME procedure of S-PLUS software.Evaluation statistics,such as AIC,BIC, Log Likelihood and Likelihood ratio test were used for model comparisons.The results showed that the branch length and branch angle models with parameters b1,b2,b3 as mixed effects showed the best performance.Exponential and power functions were incorporated into mixed branch length and branch angle model.The addition of the exponential and power functions significantly improved the mixed-effects model.The plots of standardized residuals indicated that the mixed-effect model with exponential and power functions showed more homogeneous residual variance than the mixed-effects model.Validation confirmed that the mixed model with calibration of random parameters could provide more accurate and precise prediction.Therefore,the application of mixed model not only showed the mean trends of branch length and branch angle,but also showed the individual difference based on variance-covariance structure.
Modeling Microibril Angle with Mixed Models for Dahurian Larch In this study,the sample data was based on 2 790 samples of 9 trees from dahurian larch （Larix gmelinii） plantations located in Qitaihe Forest Bureau in Heilongjiang Province.The modified Logistic model y = b1 /[1 + exp（b2 x）]+ b3 was selected to modeling microfibril angle from six models based on nonlinear regression.Then,the logistic model was fitted using nonlinear mixed-effect modeling approach based on NLME of S-PLUS software.Evaluation statistics,such as AIC,BIC, Log Likelihood and Likelihood ratio test were used for model comparisons.The results showed that the Logistic model with parameters b1,b2,b3 as mixed effects showed the best performance.Correlation structures included compound-symmetry structure （CS）,first-order autoregressive correlation structure AR（1）,moving average correlation structure MA（1） and autoregressive-moving average correlation structure[ARMA（1,1）]were incorprated into the best microfibril angle mixed model.[ARMA（1,1）]significantly improved the precision of mixed model.Validation confirmed that the mixed model with calibration of random parameters could provide more accurate and precise prediction.Therefore,the application of mixed model not only showed the mean trends of microfibril angle,but also showed the individual difference based on variance-covariance structure and correlation structure.
Multi-Objective Genetic Based Pore Combination Recognition This paper proposes an automatic method of pore combination recognition,which is an important feature to hardwood recognition.After extracting edge from wood microscopic cross-section, based on area histogram of the similar circle regions,the method classifies all regions into two classes with maximum between-class variance,so as to distinguish the pore from other textures,which are similar in shapes but different in sizes.Meanwhile, second objective function about average area of closed regions is used to improve the pore segmentation performance.At last,the method uses adjacency degree of pore set to judge pore combination.The experiments demonstrate that the task of pore segmentation can be completed successfully for all kinds of pore distribution and combination,and also the correct combinations of pores are given.
Application of Poisson Regression Model and Negative Binomial Regression Model in Forest Fire Forecasting A Poisson regression model and a negative binomial regression model(NB model) are often used in areas such as medicine and economy,but rarely in the domestic forestry sector,especially in the forest fire forecasting.Based on the data of forest fire occurrences in Daxing’anling region in 1980- 2005,this paper profoundly analyzes the application conditions and test methods of the two models.The AIC method was used to check the fitting level of the models and the capability of the models for forecasting forest fires was discussed.This study provided necessary theoretical basis and data support for the application of the two models in the field of forestry in China.
HPLC and Pattern Recognition for Identification of Four Species of Hongmu Furniture of Hongmu,cream of Chinese culture,has a long history and enjoys great popularity for its classic appearance and elegant disposition. The traditional method of the identification is to evaluate the macro form and anatomical features.In this paper,a new method based on the differences among the chemical characteristics of biological metabolites of samples is developed.In the research, high performance liquid chromatography(HPLC) fingerprints were employed to discriminate four species of Hongmu,including Pterocarpus indicus, Pterocarpus macarocarpus,Dalbergia melanoxylon, and Dalbergia louvelii.The results showed that, according to the retention time and relative peak area of different components in wood extracts,the distinction can be easily made between different species.Based on the HPLC fingerprints,similarities between samples were evaluated by correlation coefficients.The results were greater than 0.81 between the same species,and less than 0.21 between different species,which showed weak correlation between different species.In order to estimate the overall features of the fingerprints, hierarchical clustering and principal component analysis(PCA) were used and the results showed pronounced clustering effect among the same species.The investigation indicated that pattern recognition could accurately reflect the significant differences between different species of Hongmu, and can be used as a reference for quality control.
Study of Shaft Driving Force Simulation of Trees Cones Acquisition Robot The process that tree cone acquisition robot gets cones has been simulated with the process that human bends or stretches his arms in some load. And then the shaft driving force simulation of tree cone acquisition robot in the wording process was analyzed according to biomechanics laws by system modeling simulation analysis software that is used in current popular.The forces of the shafts at shoulder joint and elbow joint of the robot were analyzed,meanwhile,were calculated and drew up the figures by using Maple software.Finally,the analytical results verified the correctness of the theory analysis with Solid Dynamics software.And from the study,the findings provide important theory and parameters for improving the trees cones acquisition robot.
Development of Digital Multi-function Dendrometer Multi-functional dendrometer is a kind of forestry tool that can measure multiple factors of forest.By combining sensor technology and computer technology,a digital multi-function dendrometer has been developed,which integrated the functions of measuring height,distance,azimuth, slope,elevation,form quotient of any parts of the stem into one body at the same test.The dendrometer can fit the complex forest environment,solve the difficult problems in aspects of plant height,measure distance,central diameter and form quotient of breast height.The accuracy can meet the requirements of general forest survey.
Remote Sensing Estimation of Forest Canopy Density Combined with Texture Features The development of high-resolution remote sensing imaging technology provides a new way to the large-scale estimation of forest canopy density. The traditional inversion methods for canopy density only use spectral or topographical features of remote sensing images.However,due to the existence of the different thing with same spectrum and the same thing with different spectrum phenomena,it is difficult to improve the estimation accuracy of canopy density.Based on spectrum and other traditional features,this paper combines texture features of remote sensing images to estimate canopy density.Firstly,the gray level co-occurrence matrix (GLCM) texture features are computed using objectbased method.Then,the principal component analysis (PCA) method is applied in correlation analysis and dimension reduction of texture features.Finally, spectrum and topographical features together with texture features are introduced into stepwise regression model to estimate canopy density.The experimental results showed that compared with the traditional method only based on spectrum or topographical features,the method combined with texture features greatly improved the estimation accuracy.The coefficient of determination(adjusted R~2 ) increased from 0.737 to 0.805.The estimation accuracy increased from 81.03%to 84.32%.
Individual Tree Diameter Increment Model for Chinese Fir Plantation Based on Two-Level Linear Mixed Effects Models Based on a multilevel linear mixed model approach,an individual diameter increment model was developed for fir plantation trees growing in Jiangxi Province.The data set used in this study came from long-term permanent research plots.The database consists of total of 82 counties,365 plots, 5 416 trees and 16 248 observations.The paper chose mixed effects models instead of regression analysis approach because it allows for proper treatment of error terms and correlation in a repeated measures analysis framework.The model was defined as a mixed linear model with parameter random effect of plot,area or plot and area simultaneous.In addition the heteroscedasticity and correlation was taken into account.Mixed model calibration of diameter increment was carried out with the independent data using a different sample of complementary observations.The result showed that the total stand basal area,the diameter of target trees,the ratio of basal area of larger trees to target tree diameter,and altitude were found to be significant predictors.Both the fitting model and the calibrated model mean a substantial improvement compared with the classical approach widely used in forest management.After taking into account reasonable variance function of heteroscedasticity and correlation,the model shows better of goodness of fit than only taking into account parameter random effects.This type of modeling methodology shows flexible,precise and accurate.
Generalized Algebraic Difference Site Index Model for Ponderosa Pine in British Columbia,Canada Based upon 3 widely used base models, a total of 8 ADA/GADA site index models were derived.The data for these models in this study were obtained from 79 pith-split stem analysis plots and the estimation method was "indicator variable approach".We used both fit statistics and visual analysis to select the best-fit model,and attached more importance to the visual analysis.A comprehensive application analysis was also given to the selected model.The results showed:1) GADA outperformed ADA with respect to predictions.2) A GADA model derived from HossfeldⅣpresented the best prediction ability.It was suggested that the model be used to predict dominant height and to estimate site index for ponderosa pine stands ranging 30 -200 years in British Columbia,Canada.3) The best site index age was age of 100 years,based upon relative errors of predictions.
Monitoring Forest Growth Disturbance Using Time Series MODIS EVI Data Forest growth is mainly currently monitored using in-situ measurements in northeast of China.To effectively monitor forest growth disturbance at large scale,we attempted to use remote sensing technique,particularly,time series MODIS data from 2004 to 2006.The annual time series of 8-day enhanced vegetation index(EVI) dataset was generated and smoothed using a Savitzky-Golay filter.The EVI trajectory during growth season was simulated using a logistic model. From the simulated trajectory,the EVI area of growth season and annual EVI entropy were calculated.These two factors were combined to map the disturbance regions of forest growth. Finally,the disturbance regions were verified using a set of random samples.The result indicates that the disturbance points have distinctively higher entropy and lower peak.Some of these points also show abrupt EVI decline during the midseason of the peak phases or double peaks.This approach is demonstrated to be feasible for disturbance monitoring of forest growth.
Application of WebGIS & Knowledge Based on Forest Pests Forecasting To improve the accuracy and effectiveness of forest pests forecasting,based on current forecast model,integrating the database and WebGIS technology,a practical design and construction approach of forest pest knowledge base was put forward,and the forecast system on Web application framework was realized with satisfactory empirical results.
Analysis of Autocorrelation Associated with Spatial Sampling Estimation on Urban Greenland Coverage By taking the urban greenland as testing objective,the GeoEye-1 fusion image as background, and using Moran’s index,the correlativity of greenland units has been measured.Then,the presampling was conducted based on the measured correlativity,the systematic sampling design has been carried out at the precision 95%and 85%.By using of Kriging interpolation method,the weight of different type of greenland has been divided into the stratifications.Through the stratified sampling,the estimation of greenland coverage has been obtained. The results show that the urban greenland coverage area is 14.81 km~2,accounting for 27.73%of all urban land areas.Compared with the common sampling method,the precision of that increased about 3%. This method can also be utilized in monitoring dynamic variation of urban greenland with the real time images.
Discussion on Spatial Optimization Modeling of Water Resource Conservation Forests and Management Practice of Forest Functions According to the unification principle of system structure and system function of the Water Resource Conservation Forests,seven factors were selected from stand spatial structure,trees structure and healthy of woods,the multifunction management optimization model target was confirmed by using nonlinearity multi-objective programming approach, and the target function-stand spatial structure homogeneity index was defined to establish spatial optimization models with restraining conditions set up in diversity of stand structure and spatial structure.The spatial structure of available typical stand in the wet land area in southern Donting Lake was optimized by means of selective cutting and reinforcement planting.The results showed that the spatial structure was improved obviously and trees diversity and stand health were not weakened.It’s suggested that the established optimization model can effectively guide multifunction management,stand structure optimization and the steadiness of ecological ecosystem and it is convenient and operable in practice,and it’s very important to protect and recover ecosystem of Water Resource Conservation Forests.
Prediction of Forest Stock Volume Based on Neural Network Model BP and RBF neural network to predict forest stock volume were studied,but the study in evaluating both networks’ application effects was not conducted.In order to find a higher forecast precision,more strong applicative method,the comprehensive analysis and evaluation on the two methods were carried out in the practical application. By the correlation analysis,crown density,shady-slope and sunny-slope,TM1,TM2,TM3,TM5, TM7,NDVI,TM,(4-3),TM4/3 were selected as input variables,and the forest volume of Miyun County as output variables,RBF and BP neural network models for forecasting the forest volume were established.And the neural network training step length,training time,prediction accuracy and the applicability model of the two methods were comprehensively analyzed.The results show that the RBF neural network model is superior to the BP neural network model.
Estimation and Analysis of Green Land Variation Based on Similarity Theory The similarity theory was systematically introduced,by combining the theory and the analytic hierarchy process(AHP),and taking the dynamic changes of two-stage green land patches in Shenzhen as an example,the patches similarity of each district and each green land type were estimated.The location,shape and areas of green land unit were used as the similarity elements.Then the similarity coefficients can be defined.The overlapping number of green land patches indicated the location variation of green land.The ratio of minimum and maximum shape index of green land indicated the shape variation of green land.With the same method,the areas variation coefficient was also obtained.The results shows that based on similarity theory and method the estimation of green land variation is feasible,which can provide effective methods and accordance for the further assessment of green land development in Shenzhen Special Economic Zone.
High-resolution Remote Sensing of Textural Images for Tree Species Classification Remote sensing images show a very promising perspective for distinguishing tree species,especially those with the very high resolution ranging from 1 to 4 m.However,the traditional methodology for classifying land cover types,solely depending on spectral features,while texture and other spatial information are neglected, has the weakness such as inadequately utilization of information,low accuracies of classification,etc. Considering to the texture differences among forest species,it is more important for spatial information description of high-resolution remote sensing image to improve the precision of textural features choosing.In this study,the factors to influence the nine textural features choosing were analyzed and the results showed that the moving window size was the main factor to affect the obtaining processes of textural features based on the gray level co-occurrence matrix(GLCM) method,and the imagery was then classified combining the maximum likelihood classification(MLC) method with the original spectral values and texture features.First,this study utilized a correlation analysis of the images from a principal component analysis.Second,through multiple information sources,including textual features derived from the data.For the high-resolution remote sensing image, the most proper moving window size was determined from 3×3 to 31×31.Classification of the major tree species throughout the study area (the SunYat-Sen Mausoleum in Nanjing) was undertaken using the MLC.Third,to aid forest research,classification accuracy was improved using the GLCM.According to correlations among textures and richness of the data,GLCM provided the best window size and textural parameters. Results indicated that the texture characteristics were add in the spectral characteristics to improve the precision of the results of the classification, 19×19 window for best window.The total precision can reach 66.322 6%,Kappa coefficient is 0.584 0.Each tree species has greatly impr...Integrated Stand Growth Model of Mongolian Oak and Its Application This paper established an integrated stand growth model of Mongolian oak(ISGM_oak) using the data from 61 permanent sample plots measured in 1997 and 2007.ISGM_ oak is a group of nonlinear simultaneous equations.The method of nonlinear error-in-variable simultaneous equations is used to estimate the parameters of ISGMoak with the statistical software Forstat 2.0,so the parameter estimation of the group of correlated equations in ISGMoak is unbiased and the equations are compatible.Model validation using bootstrap method showed that both the average relative error and square error are less than 15 percent.The ISGM_ oak model can be used to simulate the stand growth with different values of site index,stand density and to draw stand density management diagram for decision-making.
Design and Implementation of Individual Tree Growth Visualization System of Cunninghamia lanceolata Along with the development of computer techniques,the application of computer in three-dimensional visualization simulation of plant growth process has been paid more and more attention. Taking Cunninghamia lanceolata as an example, the morphological parameters from the perspective of the visual simulation were designed and the trees’ morphological characteristics were analyzed based on the survey data.Combined with IFS(Iterated Function System) under the control of the growth curve,by using Object-oriented design methods, and according to API and model rendering technology provided by DIRECTX9.0,a three-dimensional visualization system on the growth and development of C.lanceolata individual tree were developed on the.NET and DIRECTX9.0 platforms,which realized the static and dynamic three-dimensional visualization simulation.
Study of Dominant Height for Chinese Fir Plantation Using Two-Level Nonlinear Mixed Effects Model Nonlinear mixed effects model(NLMEM) is built on the relationship of the fixed and random effects in the regression function.The NLMEM has an obvious comparative advantage in analyzing the longitudinal data,repeated measures data and multilevel data.Two-level NLMEM is used to analyze the dominant height for Chinese fir (Cunninghamia lanceolata).The authors outline the two-level NLMEM and introduce the parameters estimation method of the model.Based on five common Richard and Logistic models,the mixed model is built.The modeling data are used to calculate and compare with 19 models derived from each based model,and 5 optimal mixed models are built.Compared the 5 optimal mixed models with traditional regression models,it is showed that the two-level NLMEM has a better fitting effect than the regression model.
Design and Realization of 3D Management Information System for Ancient and Famous trees Based on Virtual Plant The modernization and informatization management of ancient and famous trees’ management is an important standard with which the municipal public resource management level of a region or city can be measured.Design and development of ancient and famous trees’three-dimensional management information system was realized based on virtual plant by using integrated techniques of virtual plants and Geographic Information System.The system architecture design was developed on the basis of functional requirements,and the practical system was achieved in Visual Studio 2008 development tools and OpenGL graphics standards.The system has function of ancient trees archives management,three-dimensional reconstruction of the trees surrounding environment,individual tree information inquiry in three-dimensional scene,etc.Application and dissemination of this system will greatly promote the management and protection of ancient and famous trees standardization,informalization and visualization
Study on Flame-retardation and Smoke-suppression Characteristics and Mechanism of NSCFR Flame Retardant or Wood NSCFR flame retardant is one of key factors of non-smoke combustible wood-based materials.Thermal analysis,cone calorimetry,Py-GC/MS, scanning electron microscopy(SEM) were utilized to investigate the flame-retardation and smoke-suppression characteristics and mechanisms of NSCFR flame-retardant.The results show that NSCFR flame-retardant could significantly shorten the combustion duration of wood-based materials and completely eliminate the second peak of heat release rate curve,greatly reduce heat release rate, total smoke release,mass loss rate,specific extinction area,and carbon monoxide production and carbon dioxide production,obviously enhance the mass of combustion char residue,effectively retarding the combustion and inhibiting smoke release of the wood-based material;NSCFR flame-retardant exhibits the ability of flame retardancy on wood by the conjunct mechanism of capturing free radical, diluting combustible gas,and catalyzing charring; NSCFR flame-retardant displays smoke suppression effects on wood by absorption action of nano alveolate structure together with the active catalyzing action of ironic molybdate.
Ignition Models of Thermal Thin Material in Constant Heat Flux Ignition models of tested material have important significance to fire prevention.In order to know heat transfer of thermal thin material in fire disaster,starting from the law of conservation of energy,simplifying heat capacity into a constant according to Dulong-Petit law,and three calculation formulas of ignition time of thermal thin material in a constant heat flux were respectively obtained under the conditions of ignoring heat loss,linear processing heat loss and considering thermal radiation.The relation between the ignition time and the thermal current intensity was discussed.
Flame Retardant and Mechanical Properties of Wood Powders/PE Composites The influence law of ammonium polyphosphate(APP) and coupling agents on the mechanical properties and flame retardant properties of wood powder/PE composites were studied by mechanical test and limited oxygen index(LOI) test. The experimental results show that the LOI of composites increased from 18.7%to 26.5%when the content of APP flame retardant was 30%,however the mechanical properties decreased.The maleic anhydride graft PP,titanate and silane coupling agent were used to improve mechanical properties of composites and it was implied that titanate and silane coupling agent can improve the mechanical properties of composites obviously.The limited oxygen index of wood powder/PE composites reached 27.5% when the content of titanate was 2%. Thermogravimetric analysis(TGA) shows that APP promoted charring and increased the amounts of char,thus protecting the inner matrix and increased the amount of residual char at higher temperature. The titanate coupling agent further increased the charring formed and strengthened the thermal stability,so obviously increased the flame retardant of composites.
Review on Color Change of Heat Treated Wood at High Temperature The authors reviewed the previous research results about the color changes in heat treated wood,and deeply analyzed the effect of heat treatment method and parameters including temperature and time of heat treatment,species and chemical composition on the color changes in heat treated wood.The relationships between color changes and chemical composition,physical and mechanical properties were found.The optical stability of the color of heat treated wood was studied.Some suggestions were proposed for the future research.
Research Advance of Near-infrared Spectroscopy in Wood Anatomical Characteristics Estimation As a newly current advanced analysis technology,the near-infrared(NIR)spectroscopy possesses advantages of easy operation,fast and accurate detection,low cost and non-destructive test, has been widely used in the fields including pulp manufacturing and paper-making,wood properties estimation,wood progressing,wood composites producing and wood protection.In present work, based on introduction of the basic principles of NIR and its main characteristics,an overview was conducted focusing on the research status of wood anatomical characteristics(including cellulose crystallinity,microfibril angle and fiber morphology) estimation by using NIR spectroscopy.Moreover, the application trends were prospected.
Studies on Measurement of Moisture Content by X-ray Scanning Method In order to explore the feasibility of using X-ray to measure moisture content in the drying process and have a further study on the effect of precision of moisture content when scanning through different grain directions,X-ray scanning method and weighting method were used to measure average moisture content of Cunninghamia lanceolata during hot air drying.The results show that the moisture content values of two methods were very close to one another,the determination coefficients of both were highly correlated with a value over 0.99,and the absolute deviation was below 2%;when scanning along radial direction and longitudinal direction,the precisions of average moisture content were higher than that of the tangential direction,but the deviation can be negligible in the actual measurement;in the practical application,the effect of grain direction on precision of moisture content measurement could not be taken into account when using X-ray to measure the moisture distribution of wood.
Time-Temperature Superposition in Chinese Fir Dynamic Viscoelastic Behavior Response Time-temperature superposition principle (TTSP) was used to examine dynamic viscoelastic properties of Chinese Fir(Cunninghamia lanceolata) wood at an extremely low moisture content(0.6%).Storage modulus and loss factor data were obtained at different constant temperatures ranging from 25℃to 150℃in frequency multiplexing experiments(0.1 -20 Hz).All viscoelastic curves at other temperatures were shifted along the log-frequency axis to superimpose them on a reference temperature(i.e.135℃in this study) curve.The extended storage modulus and loss factor isothermal master curves were over a wide range of frequency.The shift factors were determined to be a function of temperature and fitted into the Arrhenius equation with the least squares method.The results showed that the storage modulus data were excellently fitted into the Arrhenius model,indicating the validity of the model to characterize the dynamic stiffness behavior of dry wood in the range of 25-150℃using the TTSP. However,the time-temperature equivalence was not able to predict the damping properties.
Main Anatomy Characteristics in Cell Wall and Lignin Distribution of Bamboo Culms(Pseudosasa amabilis) The anatomy characteristics of cell wall and lignin distribution in different anatomical regions for 12-month-old bamboo species Pseudosasa amabilis was investigated.The lignin distribution was studied by means of optical microscope and confocal laser scanning microscope and the color reaction. In addition,the distribution of lignin in different tissues(fiber,parenchyma and vessel) was investigated by visible-light microspectrophotometry coupled with the Wiesner and Maule reaction.The cell walls of different tissues were all lignified and the lignin was widely distributed in different tissues, in which there was a difference between tissues and anatomical regions in lignin content.Guaiacyl lignin and syringyl lignin unit could be found in cell wall of fiber,parenchyma and vessel through Wiesner and Maule reaction and the absorbance peak of spectrum. There was no regular variation in lignin content with different radial location of culms and different location in fiber strands.The lamellation of the fiber cell wall was generally had as alternating broad and narrow layers with alternating low and high concentration of lignin.
Damage Detection of Picea asperata Sawn Timber Beams Using Modal Flexibility Curvature The local damages such as knots,decay, and cracks can be translated into a reduction of service life due to mechanical and environmental loadings.In wood construction,it is very important to evaluate the weakest location and detect damage at the earliest possible stage to avoid the future catastrophic failure.In this study,the modal testing was operated on wood beams to generate the first two mode shapes.A novel statistical algorithm was proposed to extract the damage indicator by computing the modal flexibility curvature before and after damage in timbers.The different damage severities,damage locations,and damage counts were simulated by removing mass from intact beams to verify the algorithm.The results showed that the proposed statistical algorithm was effective and suitable to the designed damage scenarios.It was reliable to detect and locate local damages under different severities,locations,and counts.The peak values of the damage indicators computed from the first two mode shapes were sensitive to different damage severities and locations.They were also reliable to detect the multiple damages.
Research on Stress Wave Tomography of Spruce Logs with Artificial Defects under Different Number Sensors In order to raise the precision of stress wave imaging technology(SWIT),under the conditions of different area and outline of simulated cavity defects in timber discs of spruce,different number of used sensors,the relationship between imaging graph defects and real defects is studied. The result shows:SWIT can display graph of defects,the precision of imaging graph relates to rate of real defect area and area of the tested wood cross section,the number of used sensors and outline shape of the defects.When the rate rises from 1.6% to 25.0%,the relative error of graph defect area and real defect area drops from 22.6%to 9.7%.When the number of used sensors is from 6 to 24,the graph of SWIT can show the existence of real defect. But the number of sensors used influences the precision of SWIT.Outline shape of defects has certain effect on detection of defects.Under the condition of the same defect area,the defects of long and narrow shape are easy to be shown by graph.The relation error of defect area of suborbicular shape is smaller than that of long and narrow shape.
Drying Characteristics and Drying Schedule Establishment of Eucalyptus pellita Wood By adopting the 100℃drying test method,the drying characteristics and drying schedule of the pre-frozen and unfrozen Eucalyptus pellita wood were studied.The results show that the pre-freezing treatment reduced the initial crack, inner crack and cross section deformation of wood, and the drying quality for the frozen wood was superior to that for the control.
Dispersion and Interface Characteristics of Nano-TiO2 Based Wood Preservatives The key problems of preparing water-based nano TiO2 wood preservatives are the particle’s agglomeration and dispersion.The influences of adding titanate NDZ-105 and sodium hexamet aphosphate on transmittance,effects of dispersion modification on crystal type,distribution and interface characteristics of modified TiO2 in wood were studied by photometric,XRD,SEM and FTIR analysis,respectively.The results show that the dispersion of nano TiO2 suspension firstly increased, then decreased as the amount of the two kinds of dispersed agent increased,when addition amount of titanate N DZ-105,six partial sodium were separately 5%and 3%-5%,the nano TiO2 wood preservatives were obtained that their dispersive property were stabilized.After dispersion modification,the TiO2 maintained the crystal diffraction characteristics of anatase;the nano TiO2 distributed in wood successfully,showing a granule or ball-shaped,and the hydrogen bond and covalent bond were combined between wood and nano-TiO2,but only hydrogen bond was combined between wood cellulose and IPBC.
Preparation and Properties of Plywood Adhesives with Soy Protein Isolate Modified by SDS The effects of mass concentration,the reaction temperature and the reaction time of soy protein isolate(SPI) and sodium dodecyl sulfate (SDS) on the adhesive strength of the modified SPI adhesives has been studied through orthogonal experiments.And the adhesive mechanism of the modified SPI adhesives was discussed.The results show that the optimum formula conditions are as follows:mass concentration of SPI was 14%,that of SDS 1%,reaction temperature 35℃and the reaction time 3 h.Under the optimum conditions, the dry adhesive strength of the modified SPI adhesives was 1.82 MPa,the wet adhesive strength was 0.82 MPa,the viscosity was 5.8 Pa·s,the solid content was 12.96%.After SDS was added into SPI, the composites of SDS-SPI were formed,the internal hydrophobic groups among the SPI molecule structure were turned out and the water resistance of the modified SPI adhesives was enhanced with an increase of the modification time.When the concentration of SDS was over a defined value,the disulfide bond was broken and the modification effect of SDS went bad.
Research Status and Prospect of Binderless Board The latest research progress of binderless board was summarized in the view of the existing binderless technology at home and abroad,and according to the bonding mechanism of binderless board,the problems an d questions in its manufacture and application at present were summed up,at last,the effect of bindless board forming process on the development of artificial board industry in China was prospected.
Shear Creep Properties for Bond Layer at Wood-CFRP Interface To know more about the bond layer’s long term properties between carbon fiber reinforced polymer(CFRP) sheets and the wood member as well as its connecting point,shear creep performance was studied using a consistent load with the Burger model.And samples were placed in dry conditions (temperature 60℃,relative humidity 90%) and wet conditions(temperature 24℃,relative humidity 45%).Results showed that the Burger model precisely simulated the bond layer’s short-term shear performance(correlative coefficient R~2≥98%). Compared to dry conditions,with wet conditions, the amount of creep was larger.Also,with an increase in thickness of the bond layer,creep deformation and stress relaxation increased.For high stress levels,a high creep rate,which could lead to a fracture of the bond layer,should be contained. Under the consideration of safety,a pressure(above 0.05 MPa) should be placed on the connection process between CFRP and wood to reduce the thickness of the bond layer.Also,in application,the shear stress level of the bond layer should be maintained within 50%of the maximum stress level.
Effects of Natural Weathering on A Wood Fiber/HDPE Composite and Application of Additives This article discussed the changes in color and chemical components on the surfaces of wood flour(WF)/high density polyethylene(HDPE) composite used outdoor in different orientation.Light stabilizer,antioxidant,and iron oxide red were introduced to reduce the changes when exposed to accelerate ultraviolet aging.The results showed that WF/HDPE composite changed significantly in color after only one month natural weathering in hot summer,especially for those facing to south and east orientation.FTIR test showed CO increased and wood index decreased.Compared to photostabilizer and antioxidant,iron oxide red pigment reduced color change more significantly.However,neither of these additives could obviously prevent flexural properties decreasing.
Biological Durability of Heat-Treated Rubber Wood In this study,the durability of rubber wood(Hevea brasiliensis) which was thermally treated at 170,185,200,and 215℃for 3 h respectively was investigated.The results showed that the durability of heat-treated rubber wood was improved,and the improvement became more obvious with the increase of the treating temperature. When treated at 185℃or lower temperature,the decay resistance of treated wood had no significant improvement.The lowest weight losses were 21.6%and 6.8%after attack by brown rot fungi(Gloeophyllum trabeum) and white rot fungi (Coriolus versicolor) respectively,which were reached by the specimens treated at 215℃.Their resistance to mold fungi was not improved,but the heat-treated wood performed better than untreated wood when both were painted.In field test,the heat-treated specimens exhibited no advantage in termite resistance compared to untreated.
Outdoor Mold-resistance and Flame Retardance of Pinus massoniana Treated with Nano-ZnO The effect of nano-ZnO,at concentrations of 2.0,10.0,20.0,and 40.0 g·kg-1,on mold resistance and flame retardance of Pinus massoniana was studied.Results showed that both drug loading and mold resistance improved as the concentration of nano-ZnO increased with the time to mold initiation for the treated P.massoniana being 3-4 weeks longer than the untreated.The time to ignition（TTI） of P.massoniana treated by nano-ZnO at 2.0 g·kg-1 was 7 s later than the untreated sample,and the total smoke release（TSR） with 20.0 g·kg-1 was lower than the untreated.The treated P.massoniana differed slightly from the untreated in heat release rate（HRR）,total heat release（THR）,mass loss rate （MLR）,and effective heat of combustion（EHC）.
Effects of Heating Rate on Properties and Structures of 3D-Cf/SiC Composites by PIP Process The properties and structures of 3D-Cf/ SiC composites prepared by rapid precursor infiltration pyrolysis process were studied.PCS solution was infiltrated into 3D-carbon fiber perform in vacuum,then these performs were dried at room temperature and pyrolyzed with three kinds of heating rate,3 900 min,1 500 min and 1 000 min respectively.The distinction of 3D-Cf/SiC samples fabricated at three kinds of heating rate was not obvious.Bending strength of sample at 1 000 min heating rate was 762.5 MPa,and a little better than the others.Three samples at various heating rate had similar micro-graph of fracture surface and fracture toughness.The research results show that mechanics performances of Cf/SiC composites did not decrease when heating rate was properly increased.
Effects of Alkaline Treatment on Mechanical Properties of Straw Fiber-reinforced Cement Board Straw fiber-reinforced cement board made from straw fiber and cement was prepared by semi-dry processing technology to investigate the effects of alkali treatment on the mechanical properties of the board.The results indicate that the board fibers were treated with 1%alkali solution showed obvious improvements in mechanical properties.After alkali treatment,hemi-celluloses of straw fiber were hydrolyzed and dissolved,which avoided hemi-celluloses hydrolyzing into monosaccharide to hinder the solidifying of cement. The fibers surface became rough,which increased the mechanical interweaving force between cement and fibers.Thereby the board’s mechanical properties were improved.At the same time,the increase of tensile strength and aspect ratio of the fibers improved the mechanical properties.
Review of Preparation and Properties of Microfibrillated Cellulose Originated from Plants Microfibrilled cellulose(MFC) is a new kind of nanoscale cellulose functional materials, having broad application prospects in many fields like food,medicine,cosmetic,paint,paper and pulp engineering,composite materials,et al.The research on MFC has been extensively conducted for the past 30 years in some developed countries,and even some relevant products have appeared in the market.On the contrast,similar studies in China were rather limited.This paper firstly introduced the properties and application of MFC briefly,and then gave more detailed description on the preparation technology of MFC and its important performance indexes. Several suggestions on the future study on MFC were also proposed.
Comparison of Quality of Pulping and Paper-Making between Normal Wood and Tension Wood of Poplar Clone 107(Populus×euramericana‘Neva’) Tree Both of straight and inclining poplar clone 107 tree were selected for studying materials in this paper.The optimal pulping conditions was established by orthogonal experimental design both for normal wood and tension wood,and the quality of pulping and paper-making between normal wood and tension wood was compared with each other. Finally,potential application for improving paper quality of tension wood through increasing beating revolutions was discussed.The result showed that the optimal cooking condition for normal wood was alkali concentration 15%,the highest temperature 164℃,time at highest temperature 75 min,and for tension wood it was alkali concentration 13%,the highest temperature 160℃,time at highest temperature 40 min.Path coefficient of effect of alkali concentration both on pulp yield and kappa value was significant at different levels.By comparison between average result of normal wood and tension wood in quality of pulping and paper-making,it was found that tension wood had higher pulping yield and lower kappa value than normal wood. Furthermore,for all mechanical properties of paper, normal wood hold higher value than tension wood, and even near two times than tension wood,such as burst index and tensile index.However,difference of tear index was quite narrow.Result of one way ANOVA showed that difference of burst index and tear index between normal wood and tension wood was significant at the 0.001 level,of tear index was significant at the 0.05 level.Based on observation of cross surface of paper,it was assumed that contribution of gelatinous layer to rigidity of single fiber had hampered collapse and compression of fiber during paper formation,which is essential for exerting combination between fibers in paper.So, mechanical properties of tension wood paper were decreased accordingly.However,owing to high cellulose content of gelatinous layer,tension wood was easier to pulping than normal wood.Mechanical properties of tension wood paper could...Mathematical Modeling of Temperature Profiles in Wood During Microwave Heating A mass of heat will be generated inside the wood by the direct interaction between microwave electromagnetic filed and water molecule or polar group in wood,which can be used to dry wood quickly or for the modification pretreatment of wood.Based on the physical law on heat transfer,a mathematical model to describe the temperature profiles of wood during microwave drying was established and simulated in this research.The results showed that the temperature profiles and its uniformity inside wood are dependent on the microwave heating methods during a microwave drying.The temperature inside wood gradually decreased along the direction of microwave transmission when the unilateral microwave heating was applied during wood drying, and the curve of temperature profiles along the thickness direction of wood is not flat.The temperature gradient with the interior temperature higher than the one in the surface layers was presented inside wood when the bilateral microwave heating were applied for wood microwave drying. Compared with the unilateral microwave heating method,the temperature distribution is more uniform along the thickness direction inside wood for the bilateral microwave heating.
Dynamic Viscoelastic Properties of γ Rays Treated Bamboo Strip in Different Temperatures The dynamic viscoelastic properties of bamboo were tested by dynamic mechanics analyzer (DMA),and the measurements were done in the temperature range of 40℃ to 300℃at frequencies of 3 Hz.The results showed that with the increase of irradiation dose,the decrease of storage modulus with increasing temperature became more dramatically.The decrease extent of storage modulus was the lowest for non-irradiated bamboo.Two mechanical relaxation processes were observed for all kinds of irradiated bamboo.The a relaxation process in lower temperature range was due to glass transition of hemicellulose and login,while the β relaxation process occurred in higher temperature range was based on glass transition of cellulose.The loss peak strength ofαrelaxation process went up as the irradiation dose increase,while the loss peak strength of β relaxation process became up first and then down,which was caused by the chemical reaction of the chief composition of bamboo.
Running Test and Optimization of Bamboo OSB Medium Experimental Line Bamboo OSB(BOSB) medium experimental line and key equipments are presented for the first time based on the analysis of BOSB production technologies and processes requirements. Component of BOSB medium experimental line and key equipments stated.The paper illustrated BOSB flaker,glue blender,orienting former.Then medium experimental line is given to a great deal of test run and optimization.The tests indicated that the medium experimental line operated smoothly for producing BOSB.Tested BOSB key performance indicators were higher than the LY/T 1580 - 2000(OSB /4).
Extraction Technology of Chinese-fir Heartwood by Supercritical Fluid Carbon Dioxide Taking extraction rate as an indicator,the extraction technology of Chinese-fir heartwood by supercritical carbon dioxide treatment was studied, and the extraction rate of the SFE-CO2 method was compared to that of traditional extraction method. The results show that when extraction processing condition were:extraction pressure 30 MPa,extraction temperature 40℃,extraction time 120 m,and flow velocity 20 kg/h,the extraction rate of SFE-CO2 was 0.99%,0.20%more than that of the traditional extraction method.However,taking the cost into consideration,it is proposed that the traditional extraction is used unless there are specific requirements.
Effects of Lay-up structure on Physical and Mechanical Properties of Laminated Bamboo Bundle Board The effects of lay-up layer numbers on laminated bamboo bundle board’s physical and mechanical properties and connection performance were analyzed.The results show that under the conditions of same layer numbers,along with the increase of the lay-up directions,the bending strength,bending modulus,compression strength and horizontal shear strength of the laminated board showed a downward trend,while using non-single direction lay-up structure,the board’s waterproof property was lower than that of single lay-up board, but the board’s connection performance was raised. Therefore,in the real application,with the condition of guaranteeing the mechanical properties of the board to meet operating requirements,the lay-up directions should be increased to improve the board’s connection performance and to increase the board’s safety.
Analysis on Volatiles Release Behavior of Poplar Wood Powder at Different Temperature by TD-GC/MS and Environmental Protection Evaluation The volatiles release behavior of poplar powder has been studied by TD-GC/MS online technique at different temperatures.The results show that the proportion of main harmful components was higher than that of beneficial in the volatiles of poplar powder at 40℃ and 90℃,the harmful components was 1.7 times higher than beneficial components. The proportions of main beneficial and harmful components were equivalent at 60℃,while the main beneficial components was 5.42 times higher than that of harmful.Taking poplar wood powder as substrate to prepare wood powder-based composites by high-pressure no-gel molding compaction between the temperature of lignin softening point and wood materials carbonization(about 150-180℃) can present a satisfactory environmental friendliness.
Application and Prospect of Organic Biocides in Timber Preservation Organic biocides as timber preservatives have aroused more and more attention,because metal salts especially arsenic,chrome and so on, have been suspected to be poisonous to the soil and aquatic animals,as well as the disposal of preserved timber wastes.Therefore,a number of effective organic biocides have been selected to prevent wood or bamboo from decay,mildew, stain and so on.Most of these products have entered into the market.With people’s increasing awareness of the environmental protection,organic biocides will eventually play important roles in timber preservation in the future.This paper summarized the studies on application of organic biocides as wood or bamboo preservatives,including resistant mechanisms,commonly applied types and effects against wood or bamboo fungi,approaches to detecting the amount of organic biocides in timber and their influences on the environment.Based on the discussion above,the authors predicted the developing prospect of organic biocides in timber preservation.
Lignin Characteristics of Steam Exploded Bamboo Residue during Hot Pressing bamboo(Phyllostachys edulis) residue was subjected to steam explosion treatment to produce superior fibers for binderless boards.Then,lignin was isolated from extract-free bamboo meal,steam exploded pulp,and binderless boards with characteristics being determined by thermo-gravimetry (TG),differential scanning calorimetry (DSC),and fourier transform infrared spectroscopy (FTIR).Results showed that:1) the yield of lignin directly extracted with dioxane-water from steam exploded bamboo pulp(SEBPL) and binderless board (SEBBL) was higher than that of milled bamboo lignin (MBL).Also,the yield of SEBBL was lower than that of SEBPL.2) FTIR results showed cleavage of ester and ether bonds between lignin and p-coumaric acid during steam explosion treatment.3) SEBBL showed two glass transitions at 115℃and 200℃, while MBL gave one glass transitions at 155℃.And 4) the modulus of rupture(MOR) and modulus of elasticity(MOE) decreased with an increase in steaming time;whereas internal bonding(IB) increased.In all cases the dimensional stability of boards did not exceed the maximum requirements for type GB/T 11718- 1999.
Application Effect Research on Intimate Natural Forestry Management Techniques for Cunninghamia lanceolata Plantation Approximating-nature forestry management technique application research is developed in Ciinninghamia lanceolata plantation for 17 years at Jiuxian Forest Farm in Songxi County, Fujian Province.The results show that the biodiversity of the C.lanceolata plantation was increased from 48.5±3.3 to 74.6±3.3 after adopting close-to-nature forestry management techniques.Compared with conventional management method,the tested forest’s soil fertility was improved:the soil moisture-physical properties and soil exchange properties were ameliorated,the soil nutrient contents were increased;the average breast height,average tree height,individual volume,Chinese fir stand volume and stand total volume were promoted by 9.24%-17.64%,8.61%- 17.29%,27.94%-58.46%,2.38%-28.64%and 8.63%-37.55%,respectively.The worse the site conditions,the greater the effect indexes with close-to -nature forestry management techniques were improved.
Optimal Rotation Age of Larix kaempferi Pulpwood Plantation by Real Options Approach The economic benefits and optimal rotation age of Larix kaempferi pulpwood plantation were analyzed under stochastic pulpwood price using real options approach in order to more effectively management to L.kaempferi pulpwood plantation in northern sub-tropical alpine area.Flexible rotation age and threshold price to different stand age of different site index plantation were developed.The result indicated that:1) the optimal rotation age of L.kaempferi plantation in site index 15,17,19,21 was 25,23,21 and 19 a,respectively,as the current pulpwood price equals 500 yuan·m-3,and the shortest rotation age was 23,20,17 and 15 a when facing to better price;and 2) Wait option should be the optimum strategy in any pulpwood price level when the stand age is lower than the shortest rotation age.
Histological Observation of Somatic Embryogenesis and Adventitious Buds Induction from Ginkgo biloba L.Different Explants in vitro Culture The differentiation process including somatic embryogenesis in different Ginkgo explants in vitro culture were studied by cytological observation.The results are as follows:1) two complete cotyledons and a embryo bud were observed in mature embryos and several secretory acavitives appeared in maturation region of embryo buds,hypocotyls,cotyledons and radicles after culturing 20 days;two incomplete cotyledons and a embryo bud primordia were found in large cotyledon embryos.The proembryo of two cells,four cells, multi-cellular,and globular embroy were developed from the callus of the small cotyledon embryos.2) The differentiation of cotyledon explants started from epidermal cells,and gradually formed meristematic cell mass in the cortical cells,and eventually adventitious buds were observed.3) The adventitious roots of Ginkgo originated in the cells at the cross of vascular cambium and vascular rays. 4) The type of rooting belongs to induction type by root primordium.The formed adventitious roots were observed after 20 days.
Effect of Forest Management Measures on Soil Respiration and Its Mechanism Global warming is one of the hottest environment problems.One of the reasons is the sharp increase of CO2 in atmosphere.Soil respiration in forest ecosystems accounts to 60%-90%of total ecosystem respiration and is therefore one of the key components of the global C cycle.This paper summarized different responses of soil respiration to forest management measures,and described the relevant researches at home and abroad on the effect of management measures like harvesting,forest fertilization,soil improving(Liming),litter removal, and prescribed burning on soil respiration.
Research Progress of Maintenance Technology of Long-term Productivity of Plantation in China Plantation resource is an important component of forest resources.Overall plantation quality is not high in China,and the problems like low growth,low preserving rate and low productivity are commonly observed.This paper reviewed the historical background of the research on plantation productivity,described factors affecting plantation productivity including site conditions,initial planting density,thinning measures,ground clearance,and continuous planted algebra and fertilization.Finally,it was proposed to carry out key technology system research on plantation productivity maintenance and strengthen the research on the long-termness, systematic development and multi-purpose of plantation productivity.
Advances in Molecular Biology for Plasma Membrane Intrinsic Proteins(PIPs):A Review Water is an important component in plant cells with plant aquaporin being the major protein for water transport in and between plant cells.As a subfamily of plant aquaporins,the plasma membrane intrinsic proteins（PIPs） located in the plasma membrane are classic,high water,selective channel proteins.This paper focuses on recent advances in the molecular biology of PIPs concerning structural characteristics,biological function,and a regulation mechanism.PIPs possess two highly conserved domains:GGGANXXXXGY and TGI/TNPARSL/FGAAI/VI/VFWF/YN.PIPs can also be divided into two phylogenetic subgroups named PIP1 and PIP2.PIP1 possesses longer N terminal sequences and shorter C terminal sequences than PIP2 with conserved amino acid sequences respectively.Studies of transgenic plants and expression in Xenopus oocytes cells indicate that PIPs not only may facilitate transport of water and small neutral solutes like CO2 and glycerin,but they also possess many physiological functions. The functions of plant aquaporins are regulated by many factors including post-translational modification,heteromerization,pH value,and divalent cations.These results indicated that PIPs act as a pivotal role in water and small neutral solutes transport in plants.
Research Progress on Speciation of Selenium Compounds in Plants Selenium(Se) is an essential trace element, which humans and animals take directly or indirectly from plants.This paper reviewed the recent research progress on speciation of selenium compounds in plants,including the kinds of selenium compounds and their metabolic pathways,and the technology for sample treatment,separation,and determination. Organic selenium compounds are the major parts of the selenium speciation in plants.The technology of ultrasonic-microwave synergistic extraction combined with enzymatic hydrolysis is useful in sample preparation.HPLC-ICP-MS is widely used in determining selenium speciation.It is important to develop more standard selenium compounds and pay more attention to selenoprotein in plants.ESMS,ESMS -MS and MALDI-TOF can be applied to identifying the unknown selenium compounds.The application of IDA in determining both the metabolic pathways and the structure of large selenium molecules will be a major aspect for the future research.
Optimization of PCR system in EST-SSR analysis of Pinus massoniana Lamb All factors affecting the PCR system in Pinus massoniana Lamb were investigated one by one.The results show that the optimum PCR system of EST-SSR were:2μL 10×Buffer(Mg2+ Free), 30 ng template DNA,0.187 5 mmol/L dNTPs, 3.75 mmol/L Mg2+,8 pmol primer pair,1.0 U Taq DNA poly-merase in total 20μL reaction system. Finally,a total of 11 isolates of P.massoniana was used for testing the stability of the PCR amplification.The results prove that the optimum PCR system was stable,reliable,highly repetitive.
Research Status and Prospect of Larix spp.Wood Modification Larix spp.wood is one of the major fast-growing tree species in China,which also has the most forest storage in the northeast of China.Several key properties modification methods and achievements of Larix spp.wood were summarized based on their characteristics.Technology problems of properties modification and new use prospect of modified Larix spp.wood were all discussed.
SCAR Marker and Detection Technique of Bursaphelenchus xylophilus OPM05-M2100,the specific RAPD fragment of Bursaphelenchus xylophilus,was collected from agarose gels and purified.Then,the purified fragment was inserted into the pGEMR -T Vector that was transformed into Escherichia.coli and cloned and sequenced.Based on the sequence of RAPD marker,the sequences characterized amplified region（SCAR） primers were designed by the aid of the software Oligo5.0.The forward primer is M05F2 （5’-CGGGT CATGG CTGGA GGTAT CGT-3’）,and the backward primer is M05R1(5’-TGGCT CAATG GCAAA TCCTT CGTA-3’.The specific fragment (OPM05-M2100) was successfully converted to SCAR marker(SCAR-M05-X600) by using M05 F2/R1,which was the specific markers of B.xylophilus.Then, the DNA of 92 isolates of Bursaphelenchus,B. mucronatus,B.hofmanni,Aphelenchoides macronucleatus and Seinura sp.which were isolated from dead pines,were marked,and the DNA of a single nematode extracted with a simple method was detected using this set of specific primers.The results indicated that the PCR product of all 81 isolates of B.xylophilus was a clear and bright fragment about 600 bp with M05 F2/R1.But eight isolates of B. mucronatus,one B.hofmanni,one A.macronucleatus and one Seinura sp.had no any fragments.Assay M05 F2/R1 also successfully detected single pinewood nematode.Therefore,the specific pairwises would be used for constructing identification kits of B. xylophilus,implementing the aim of quick detection, and achieving the purpose of identify juvenile successfully.
Distribution and Host Plants of Asemini in China and Potential Invasive Threat of Alien Species Asemini is a Northern Hemisphere cerambycid tribe,and an important forest pest, mainly causing damage to coniferous plants.More important,as one kind of quarantine insects,Asemini can bring about many troubles in timber trade, therefore,the alien species should be paid more attentions and need to be quarantined in order to prevent them to be introduced to China.In China, there are 4 genus 26 species of Asemini.Host plants of Asemini include 15 genus 36 species of 7 families, and the main host plants are in Pinus,accounting for 30.56%of the total.A fauna analysis indicated that 15 species of Asemini distributed in the Palareartic Realm,accounting for 57.69%of the total. The species predominated in China,probably because gymnosperms were the main vegetable type in this region.This paper lists all the known species and genera of Asemini and their host plants in China,and discusses their distribution.The aim is to arouse the concerns of these insects and provide a reference for the relevant work.
Fire Growth Models and Software Fire growth model can predict fire behavior,which can guide fire fighting activities and assesses fire management policies.This paper analyzed the main factors affecting fire simulation, and summaried the current growth models including empirical,semi-empirical and physical models.The widely used fire growth simulation softwares were outlined in the paper,which include Prometheus, Behave Plus,Farsite,etc.Finally,the paper discussed the limitations of fire growth models and their future development.
A Measuring,Reporting and Verifying System for REDD+ Activities in China Challenges and focus that Measureable, Reportable and Verifiable of REDD+ activities will face are analyzed base on provisions relate to MRV for REDD+ in UNFCCC.It will face the challenges of lake of messages in estimating biomass carbon storage and reference level,certification standards, the national methodology of REDD+ activities,and financial support if measurable,reportable and verifiable REDD+ activities are developed in China. Based on the results of the analysis,the different types for REDD+ activities that adapt to Chinese situation are put forward,and it was designed that the framework on Measuring,Reporting and Verifying System for REDD+ activities in China including general indicator such as objectives, implementation,contribution to sustainable development and poverty eradication,environment effectiveness,sustainability and cost-effectiveness.
Detection to Pathogens of Poplar Cankers by Multiplex PCR Technique Fungal pathogens causing poplar canker diseases are cosmopolitan in species,and have a wide range of hosts.These pathogens have diverse anamorphs and their morphology overlaps with each other;Their teleomorphs are hardly discovered in nature.Furthermore,the identification of these pathogens is usually limited by the geography,host and taxonomic knowledge.Therefore,a culture-independent method used to identify determine pathogens is expected to be developed for field diagnostics.Through amplifying,sequencing and analyzing multiplex nucleic acid templates and genetic marked target sequences,a multiplex PCR technique has been established and used to directly detect various environmental samples.In this study, four pathogen strains and environmental samples were amplified using fungal universal primers ITS1/ ITS4 and EF1-728F/EF1-986R by general PCR and multiplex PCR.The amplicons were sequenced,and then aligned in GenBank.The result showed that the multiplex PCR was able to successfully amplify the target gene and identify the pathogens from environmental samples in the condition of an annealing temperature of 55.6℃and primers final concentration of 0.2μmol·L-1.The multiplex PCR could amplify the target at the concentration level of approximately lng of genomic DNA.This method would provide a useful tool for the identification of canker pathogens by the multiplex PCR and the high-throughput DNA microarray detection of environmental samples.
Effects of Different Forest Fire Intensities on Microbial Community Functional Diversity in Forest Soil in Daxing’anling Microbial community functional diversity is a sensitive indicator of soil.Forest fires can change microbial community functional diversity.In this research,the fired soil samples were collected from Huzhong of Daxing’anling in Heilongjiang Province. The functional diversity of soil microbial community was detected by BIOLOG system.The average well color development(AWCD) in BIOLOG plates indicated the ability of carbon substrate utilization of microbial community.The indices of Shannon, Simpson and Mcintosh were calculated to show the richness,dominance and evenness of the functional diversity,and the principal component analysis of substrate reactions reflected the main carbon sources utilized by microbial community.The results showed that all the samples exhibited the reduction of AWCD during the first 144 hours of incubation,but there were obvious differences in the reduction degree among the samples.All kinds of fire intensities could influence microbial community functional diversity. The low fire intensity increased the richness (Shannon),dominance(Simpson) and evenness (Mcintosh) of microbial community.However,the intermediate and high fire intensity reduced these parameters,suggesting that the burned soil emitted gaseous nitrogen,a number of organic carbon and available phosphorus,which caused the reduction of the microorganism in quantity and type,and change in soil ingredients.The organic material reduced in the burned soil,in the same time,the pH values rose,which changed environment in which microorganism lives.The changed environment might not be conducive to activities of the microorganism.The principal component analysis showed that the main carbon sources for soil microbes were carbohydrates and amino acids and the carbon substrate utilization patterns in different samples were significant different.The results indicated that functional diversity of soil microbes were altered by forest fires,and the ability of microbes to utilize carbon source an...Effects of Pulsed Magnetic Field on Biochemical and Physiological Characters and Ultrastructure of Pine Wood Nematode In this paper,we employed the pulsed magnetic field(PMF) processing to investigate the effect of different pulse rise time and treatment time on the survival,reproduction,cellulase activity and surface characteristics of the pine wood nematode (PWN).The results showed that the wider pulse and the longer treatment time were able to reduce the survival,and inhibit the cellulase activity and reproduction of PWN.The 4th instar and females had a strong resistance to the pulsed magnetic field. With pulse rise time of 10 ms and the treatment of 60 min,the adjusted mortality of PWN was 100%. After the PMF treatment,the cellulase activity of PWN increased within a short time,and then declined with the treatment time.The observation with a scanning electron micrograph(SEM) revealed that there was no significant change in morphology of PWN,but the quantity of rod-shaped bacteria carried by PWN was reduced.
Deposition Effects of Electrostatic and NonElectrostatic Aerial Spray In this study,we compared the aerial electrostatic spray with non-electrostatic spray by helicopter R44 and fixed-wing aircraft Y5B equipped with an own-made aerial electrostatic spraying system.The results showed that the spray deposits on targets and leaves of tree crowns were notable enhanced comparing with the non-electrostatic and conventional aerial spray.The spray deposits were fine,uniform and the densities were 1.0-1.75 times higher than the non-electrostatic spray.Deposit rate of the electrostatic spray on the backs of leaves by helicopter R44 was 2.15 times of the non-electrostatic, and 3.31 times of the conventional aerial spray.The deposit rate of the electrostatic spray on the backs of leaves by the Y5B was 2.38 times of the non-electrostatic,and 3.44 times of the conventional aerial spray.
Land Degradation Control Policies and Practices in Canada and Its Implications to China Land degradation is one of the significant environmental problems in both China and Canada, which seriously threatens the sustainable development of national economy and society of both countries.This paper introduced some policies, regulations and department coordination mechanisms of land resource management,restoration/ rehabilitation of degraded land,forest resources management,agricultural environmental protection and mineral area land reclamation in Canada.Some practices,experiences and effects in land degradation control of Canada were listed and analyzed.Finally,it was suggested that the successful experiences of Canada in technology,policy and management for land degradation control should be learned for improving efficiency of land degradation in China’s western region.
Variation in Leaf Shapes of Nitraria Species and Effect on Leaf δ13C Leaf shapes are not only the useful indicators in plant taxonomy,but also the important factors affecting energy and material exchange in leaves.In this paper,we collected and scanned the leaves of Nitraria tangutorum in Dengkou of Inner Mongolia Autonomous Region（the mean annual precipitation 145 mm） and Minqin of Gansu Province （the mean annual precipitation 115 mm） and N. sphaerocarpa in Dunhuang,and then analyzed leaf shape parameters with Image - Pro Plus6.0 image processing software and leafδ13C values in the isotope laboratory of the Chinese Academy of Forestry.The result showed that:1) as leaf area increased with increasing water availability the increases in the leaf length and width were asynchronously;2) with the same leaf width,the 1 eaves of N.tangutorum and N.sphaerocarpa were significantly longer in high water available conditions;and 3) although there were significantly differences in water availability between Dengkou and Minqin,as well as between the bottom and middle of the alluvial fan near the East Lake in Dunhuang,the leafδ13C values of N.tangutorum or N.sphaerocarpa were similar in different water conditions（P>0.05）.Our results suggested that the ratio of leaf perimeter to area would be an important factor which linked leaf shape to plant water physiology.During growing procedure of leaf area,leaf length increase was prior to its width to alleviate the reduction in ratio of perimeter to area and maintain water use efficiency of the plant.
Progress in Study on Response of Arid Zones to Precipitation Change The pattern of precipitation,including precipitation amount,frequency and intensity,may change in the future according to the prediction of climate change.In arid zones,the soil dynamics, plant growth and vegetation change,desertification and hydrology might be affected by precipitation change.In general,the precipitation in extreme arid zone and arid zone showed an increase tendency whereas the precipitation in some area in semi-arid zone and sub-humid arid zone showed a decrease tendency.The increase of precipitation could enhance the growth of biological soil crust,improve soil water status,promote plant growth,increase vegetation coverage,facilitate the change from desert vegetation to grassland vegetation,and it is benefit to the reversion of land desertification.In addition,the increase of precipitation could also increase the river runoff,lake storage and promote the occurrence of flood,while the decrease of precipitation has the adverse effect.These studies will benefit the prediction of the possible response of ecosystem processes to the potential change of precipitation pattern in arid zones in the future,and it is important to the conservation of natural vegetation and the control of desertification.More field experiments and studies should be conducted in the future,including the effect of increased precipitation or temperature,nitrogen deposition and CO2 on soil,vegetation,desertification and hydrology of arid zones,so as the more persuasive results could be obtained from these experiments and studies.
Algorithm Derivation of Winter Facies Wind Protection of Shelterbelts Structural Parameters and Wind Permeability Coefficient To solve the problem in the absence of permeability algorithm in China’s forestry industry standard "Technical Specification for Oasis Shelter Belt Construction(LY/T 1682—2006)",by defining and calculating the forest structural parameters-porosityβ,stumpage surface porosity S",stumpage volume porosity V’,aboveground surface area density C,aboveground bulk density W,the relations among these structural parameters and their relations with wind permeability coefficientα,shelterbelt width D and mean diameter of branch d were calculated,which is expressed as:W=V’/D=dC/4 =dS’/4D=-πdlnβ/4D = -0.1πZdlnα/D.It is proofed that the main structural parameters have homogeneity and different structural parameters are of inheritance and consistency on the nature,there is no exclusivity in the strict sense,and is convertible under certain conditions,which is convenient for evaluating the wind-resistance effect of shelterbelt. A set of computational formulas for wind effect evaluation of farmland shelterbelt in dry and sandy area in northern China is derived.
Research on Accounting Recognition and Measurement of Forest Ecological Assets Current accounting standards and systems do not include the accounting of forest ecological assets.With the increasing attention that people pay to forest ecological issues and the needs for accounting information disclosure,its value accounting has become a forefront issue and hot topic in the accounting profession.The profound issues about its particularities,accounting recognition and measurements are to be solved. Based on the analysis of the features of forest ecological assets and its impacts on accounting recognition and measurement,this paper proposes that accounting recognition should be based on the appraisal and a fair value model is suggested for initial and further measurement of forest ecological assets.For the fair value measurement, the appraisal techniques of non-market values should be given more consideration.And its value appraisal methods should refer to the existing mature ecological economic or environmental economic appraisal methods.
Legal Issues of Rights to Manage Understory Land Management of the understory land is an economic form to develop cultivation and breeding in making use of the forest ecological environment.It is also an important means to increase the income of forest farmers in the forestry regions after the reform of forestry real rights.This paper investigated the management status of understory land,and analyzed the impacts and destruction of its improper management upon the forest ecology environment.The management right of the understory land is a restricted right of property,because the management is related to the ecology protection of forest and woodland.In addition to private property rights,it should also comply with the arrangement of national forest management.Therefore,while encouraging and developing the understory land management,it’s important to establish a legal system for executing the management rights,and the management of the understory land should be included in the scope of the forestry management.
New Positioning of Forest in Green Development In the 20 years after the UN Environment and Development Conference in 1992,the essential issues in relation to sustainable development have been unsolved.The upcoming "Rio + 20" conference put the focus on the shift towards green development. To achieve this requires the change of some ideologies that dominate human actions,such as the concepts of wealth,welfare and security,and it also require identifying the new position of nature resources, especially the position of forest.It was pointed out in the paper that forest is the foundation of socioeconomic development and constitutes basic wealth,basic welfare and basic security of the whole community under the green development context. Nevertheless,it is a must to aggressively invest and develop green economy.It was also proposed to set up forestry development organizations,investment mechanisms,policy system and research & education system compatible with green development. Moreover,some forestry policies that should be revised were combed.
Comparative Study of Overseas Forest Carbon Financing Patterns and Its Inspiration on China The role and position of forestry in response to the issue of climate change have been increasingly concerned by more and more countries and the international community.The cost incurred in forest carbon sequestration is lower than other options to mitigate climate change.However,the fund’s gap becomes the main barrier to reducing carbon emissions caused by deforestation and forest degradation(REDD) and enhancing carbon storage in forests(REDD +) and also becomes the concerns of governments,academic community and enterprises.Based on the comparative analysis of overseas forest carbon financing models,the paper pinpointed their development trend and proposed solutions to financing for forest carbon sink in China.
Land Degradation Control in Arid Ecosystem under Climate Change Context Climate change is the largest stress factor challenging global territorial ecosystem.The discussion on land degradation control in arid ecosystem under the context of climate change for increasing the capacity to mitigate and adapt to the climate change and gradually restoring the integrated production potential originally possessed by land ecosystem is a pressing issue to address.The paper analyzed the effect of climate change on land degradation in arid ecosystem,and described the protection and rehabilitation of forest,grassland and farmland ecosystems,and the enhancement of the response to climate change and the improvement of people’s livelihood from the viewpoint of integrated ecosystem management.This study is expected to offer a new concept for land degradation control and sustainable management of arid ecosystem in the context of global climate change.
Analysis of Institutional Dilemma of Forest Property Mortgage Loan Forest property mortgage opens up a new financing channel to revitalize forest resources assets, but there are many restrictions to forest property mortgage loan from relevant legal norms and practices concerning mortgage loan policies.The paper analyzed the institutional dilemma of forest property mortgage loan in accordance with relevant laws and policies,and then made the recommendations,in order to provide a meaningful reference to perfect forest property mortgage loan.