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Regeneration And Plant Diversity Maintenance Of Populus Euphratica Forest In Ejina Oasis

Posted on:2012-11-01Degree:MasterType:Thesis
Country:ChinaCandidate:W L ZhouFull Text:PDF
GTID:2143330335467298Subject:Ecology
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Oasis is not only the most important part of desert ecosystem, but also the most sensitive region. Influenced by desert arid climate, desert riparian forest made up by Populus euphratica Oliv. is non-zonal vegetation as well as the main part of the Ejina oasis of Inner Mongolia. Due to the lack of understanding on the function of Populus forest on maintaining eco-balance in desert region, P. euphratica forest suffered havoc, withering phenomenon is very serious. Therefore, to solve the related problems concerning the P. euphratica forest and biodiversity conservation, it is crucial to move on to study the P. euphratica regeneration and the plant diversity under it.This study was conducted in P. euphratica forest in Ejina Oasist, and we investigated the regeneration and composition of Plant Diversity. Communities were divided into 14 associations on the basis of their species importance 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 (βw=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 species composition.At present, the regeneration of P. euphratica Forest communities maintain mainly depends on the root sprout breeding. It was found from the control experiment on the possible influential factors of the generation and growth of root sprouts, that the combination of soil below the forests, the proper moisture at 15% and the near-mature forest is the optimal condition for the growth of adventitious buds of roots of P. euphratica. While the combination of riparian puddled soil, the water content at 15% and the horizontal-went roots in nature forests is the best condition for the generation of sprouts of adventitious roots, and the average amount of sprouts in the experiment is 35.6. The water condition of the moisture at 5% is the critical condition for the generation of adventitious buds and is also one limiting factor during the development of adventitious buds becoming the root sprouts.It is proper to generate sprouts on adventitious roots under light while the shade environment is preferred by the seedlings on roots. With the help of the large amount of horizontal-went roots underground, P. euphratica generates the sprouts which are difficult to keep on growing after coming out of the ground, leading to the phenomena that a large amount of seedlings generated on the roots but only a small amount of them could be alive in the future.
Keywords/Search Tags:Ejina Oasis, Populus euphratica Oliv., Plant diversity, Root suckers
PDF Full Text Request
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