An experimental approach to addressing ecological questions related to the conservation of plant biodiversity in China We briefly introduce and describe seven questions related to community structure and biodiversity conservation that can be addressed using field experiments,and provide the context for using the vast geographic diversity,biodiversity,and network of Nature Reserves in China to perform these experiments.China is the world’s third largest country,has a diverse topography,covers five climatic zones from cold-temperate to tropical,has 18 vegetation biomes ranging from Arctic / alpine tundra and desert to Tropical rain forest,and supports the richest biodiversity in the temperate northern hemisphere( > 10%of the world total). But this tremendous natural resource is under relentless assault that threatens to destroy biodiversity and negatively impact the services ecosystems provide. In an attempt to prevent the loss of biodiversity,China has established 2,729 nature reserves which cover 14.84% of the nation’ s area. Unfortunately underfunding,mismanagement,illegal activities,invasive species and global climate change threaten the effectiveness of these protected areas. Attention has focused on protecting species and their habitats before degradation and loss of either species or habitats occur. Here we argue that we must move beyond the simple protection of ecosystems,beyond their description,and by using experiments,try to understand how ecosystems work. This new understanding will allow us to design conservation programs,perform restoration of damaged or degraded areas,and address resource management concerns( e.g.,agriculture,logging,mining,hunting) more effectively than with the current approach of ad hoc reactions to ecological and environmental problems. We argue that improving our understanding of nature can best be done using well designed,replicated,and typically manipulative field experiments.
Plant diversity in a changing world： status, trends, and conservation needs
Six new species of Elatostema （Urticaceae） from Yunnan Six new species of the genus Elatostema( Urticaceae),E. dentatocaudatum,E. baoshanense,E. cuipingfengense,E.viridicostatum,E.flexuosicaule and E.globosostigmatum,from Yunnan Province,China are described and illustrated. The diagnostic differences between the six new species and their respective allies are given.
History and conservation of wild and cultivated plant diversity in Uganda： forest species and banana varieties as case studies
How to conserve threatened Chinese plant species with extremely small populations？ The Chinese flora occupies a unique position in global plant diversity,but is severely threatened. Although biodiversity conservation in China has made significant progress over the past decades,many wild plant species have extremely small population sizes and therefore are in extreme danger of extinction. The concept of plant species with extremely small populations( PSESPs),recently adopted and widely accepted in China,lacks a detailed description of the methodology appropriate for conserving PSESPs. Strategies for seed sampling,reintroduction,protecting PSESP locations,managing interactions with the local human population,and other conservation aspects can substantially differ from those commonly applied to non-PSESPs. The present review is an attempt to provide a detailed conservation methodology with realistic and easy-to-follow guidelines for PSESPs in China.
Gamma-aminobutyric acid mediates the nicotine biosynthesis in tobacco under flooding stress Gamma-aminobutyric acid( GABA) is a four-carbon non-protein amino acid conserved from bacteria to plants and vertebrates. Increasing evidence supports a regulatory role for GABA in plant development and the plant’s response to environmental stress. The biosynthesis of nicotine,the main economically important metabolite in tobacco,is tightly regulated. GABA has not hitherto been reported to function in nicotine biosynthesis. Here we found that water flooding treatment( hypoxia) markedly induced the accumulation of GABA and stimulated nicotine biosynthesis. Suppressing GABA accumulation by treatment with glutamate decarboxylase inhibitor impaired flooding-induced nicotine biosynthesis,while exogenous GABA application directly induced nicotine biosynthesis. Based on these results,we propose that GABA triggers nicotine biosynthesis in tobacco seedlings subjected to flooding. Our results provide insight into the molecular mechanism of nicotine biosynthesis in tobacco plants exposed to environmental stress.
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