生境异质性对一年生短命植物物种多样性分布格局的影响OACHSSCD

Plant species diversity is a direct representation of plant diversity,and its distribution patterns and influencing factors have always been important research topics in ecology and biogeography.At present,the research on plant species diversity is mostly limited to single-factor driven analysis,and there is still a lack of systematic understanding of the coupling effect and spatial distribution of multi-scale habitat heterogeneity.In this study,we took annual ephemeral plants in the northern desert area of Xinjiang as the research object,measured plant species diversity by alpha diversity index,and explored the impact of habitat heterogeneity on the species diversity distribution pattern of annual ephemeral plants based on field investigation and environmental factor analysis.The results showed that:(1)A total of 70 annual ephemeral plants were investigated,mainly in Brassicaceae,Asteraceae,Poaceae,Boraginaceae and Fabaceae plants,accounting for 32%,14%,10%,10%and 7%of the total number of plants surveyed,respectively,and the species diversity of annual ephemeral plants in different habitats was significantly greater in Sandy desert than in Gobi desert and significantly larger than Saline-alkali desert(P＜0.05).(2)The results of linear fitting showed that the species diversity of annual ephemeral plants was significantly positively correlated with mean annual temperature and average soil particle size(P＜0.05),and negatively correlated with soil pH,soil electrical conductivity,soil organic carbon and soil total nitrogen(P＜0.05).(3)The results of random forest analysis showed that soil pH,soil electrical conductivity and average soil particle size were of high importance to the species diversity of annual ephemeral plants.(4)The results of structural equation modeling showed that soil pH and soil electrical conductivity had a direct impact on the species diversity of annual ephemeral plants,while altitude,mean annual temperature and average soil particle size had indirect effects.This study suggests that considering multiple environmental factors and their interactions can better explain the distribution pattern of species diversity in annual ephemeral plants.The results can provide a theoretical basis for desert plant conservation and desert vegetation restoration.