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Université du Xinjiang (2019)

Stability of Typical Desert Plant Populations, Communities and Ecosystems Across Water-salt Gradient

杨启;

Titre : Stability of Typical Desert Plant Populations, Communities and Ecosystems Across Water-salt Gradient

Auteur : 杨启;

Grade : Master’s Theses 2019

Université : Université du Xinjiang

Résumé
The arid and semi-arid areas in the northwest are distributed with typical fragile ecosystems.Maintaining ecosystem stability is particularly important for the conservation and sustainable development of biodiversity in this area.This paper uses the desert plant ecosystem of the Ebinur Lake Wetland National Nature Reserve.For the research object,the changes of population,community and ecosystem stability under different water-salt gradients were discussed,and the factors affecting community stability were discussed from the perspective of environmental factors,diversity and complexity.The following conclusions were drawn :(1)The population stability under different water-salt gradients was the largest in the population of Herba Salsola collina and Suaeda salsa,and the stability of the population changed to some extent with the change of water-salt gradient.The coefficient of variation of species population density and the improved calculation method of Godron stability showed that the stability of community under different water-salt gradients was high water and salt > low water and salt > middle water and salt community.The ecosystem is in an unstable state.The stability at different scales is population > community > ecosystem stability.(2)There was a certain degree of change in species composition under different water-salt gradients.With the decreasing of water-salt gradient,the proportion of herbaceous decreased,the proportion of shrub decreased,and the change of arbor was more stable.Both the Simpson diversity index and the Pielou evenness index are the highest under high water and salt.In the middle water and slat is similar to the low water and salt.The Shannon-Wiener diversity index and the Margalef richness index are both the highest under low water and salt.There were significant differences in soil factors under different water-salt gradients.The results of plant diversity and soil factor RDA analysis showed that the soil factor explained 48.8% of plant diversity under the high water and salt gradient,10.5% of the salt in the middle water and slat,and 8.4% of the plant diversity under the low water and salt gradient.Species diversity has a significant effect on community stability,and this effect increases with decreasing water-salt gradients.(3)Functional diversity in different water-salt gradients showed high water and salt > low water and salt > middle water and salt.Under different water-salt gradients,the interpretation of the functional factors of soil factors on the functional diversity was ranked as high water and salt > low water and salt > middle water and salt,and the interpretative amount explained 68.9% functional diversity under high water and salt,respectively.Salt in water explained 11.2%,and low water and salt explained 15.8%.There was a positive correlation between species diversity and functional diversity under different water-salt gradients,and the correlation was the highest under low water and salt

Mots clés : desert plant; water-salt gradient; species diversity; functional diversity; complexity; stability;

Présentation (CNKI)

Page publiée le 24 mai 2020