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Plant diversity and its maintenance in Populus euphratica riparian forests in the Ejina Oasis,China 被引量:2
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作者 zhou wei-lei YANG Xue-qin +4 位作者 HAO Peng LIU Qian-wen CAO De-chang Tom BARIBAULT LI Jing-wen 《Forestry Studies in China》 CAS 2010年第2期55-61,共7页
The dynamic environments in riparian zones support a variety of life-history strategies, which constitute a fundamental mechanism for development and maintenance of biodiversity in riparian forest ecosystems. To demon... The dynamic environments in riparian zones support a variety of life-history strategies, which constitute a fundamental mechanism for development and maintenance of biodiversity in riparian forest ecosystems. To demonstrate the effect of life-history strategies on biodiversity, we investigated community-level diversity and its relationship to environmental variability in the riparian Populus euphratica forests of the Ejina Oasis. Communities were divided into 14 associations on the basis of their species impor- tance values. The Simpson's index, Shannon-Wiener index, Pielou's evenness index and the regional Whittaker's index were applied to calculate community diversity. An ordination of the sample plots was carried out by correspondence analysis (CA). Biodiversity was relatively low across the entire study area, but there was high community diversity (flw = 8.09) due to the spatial heterogeneity of habitats in different plots. In addition, we investigated the relationship between biodiversity and several environmental factors, such as water availability, community components and soil conditions. We conclude that the heterogeneity of soil and water availability drives community diversity patterns in riparian zones and that community-level diversity favors the maintenance of species diversity in the P euphratica forests in the Ejina Oasis. 展开更多
关键词 plant diversity riparian zones maintenance mechanism Populus euphratica Ejina Oasis
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Spatial pattern and utility of Populus euphratica seed rain:a simulation study combined with field investigations 被引量:1
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作者 HAO Peng LI Jing-wen +2 位作者 zhou wei-lei LIU Qian-wen ZHANG Yu-bo 《Forestry Studies in China》 CAS 2012年第3期169-179,共11页
Seed dispersal is a fundamental process affecting destinies of seeds and seedlings, as well as regeneration dynamics and distribution patterns of communities. Recently however, declining Populus euphratica forests hav... Seed dispersal is a fundamental process affecting destinies of seeds and seedlings, as well as regeneration dynamics and distribution patterns of communities. Recently however, declining Populus euphratica forests have failed to regenerate by seeding, while the spatial pattern and utility of their seed rains are unclear. In this study, we designed a model to simulate seed rains based on field investigations by fitting our observations to a normal distribution and testing the model with data from three years, with ac- ceptable results. We examined the simulated results of dispersed seeds patterns on the classification of three factors, i.e., density of Sophora alopecuroides, surface soil moisture and surface soil salinity. The results of seed rain simulation show that over 70% of seeds were dispersed and confined to each of the three plots where their mother trees located. The proportion of 3:7 seeds dispersed inside and outside each plots remained largely unaltered. The differences in the amounts of dispersed seed among the different levels of each of the factors were not significant, although the distributing pattern of P. euphratica in each plot varied. Therefore, in P. eu- phratica communities, the amount of seed does not become a constraint in subsequent germination, although the surface environment does. We conclude that successful P. euphratica seed regeneration relies on less than 30% of seeds dispersed over longer distance to colonize favorable growth habitats. 展开更多
关键词 Populus euphratica forest seed rain spatial pattern UTILITY wind direction
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基于环糊精构筑的镧系稀土发光超分子组装体 被引量:3
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作者 周维磊 陈湧 刘育 《化学学报》 SCIE CAS CSCD 北大核心 2020年第11期1164-1176,共13页
镧系元素由于其优异的发光特性,如长寿命的激发态、尖锐的线状发射带和较大的Stokes位移等,在发光材料中表现出极大的优势,被越来越多地应用于高级功能发光材料的设计中.而环糊精作为第二代超分子主体分子具有易于功能化修饰以及特异性... 镧系元素由于其优异的发光特性,如长寿命的激发态、尖锐的线状发射带和较大的Stokes位移等,在发光材料中表现出极大的优势,被越来越多地应用于高级功能发光材料的设计中.而环糊精作为第二代超分子主体分子具有易于功能化修饰以及特异性结合发光客体等优势而被广泛地用于构筑发光材料、荧光传感等超分子体系.作者从基于环糊精的镧系稀土配位化合物超分子组装体的构筑出发,对不同镧系环糊精发光材料的最新研究进展进行综述,为开发构筑新型多功能化镧系发光材料提供参考.最后,提出了稀土发光材料目前所遇到的科学问题,并对基于环糊精稀土发光材料的发展方向进行了展望. 展开更多
关键词 超分子 环糊精 镧系元素 发光
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