鄂尔多斯遗鸥自然保护区植物群落及土壤理化性质空间异质性OA

[Objective]Taking Ordos Larus relictus National Nature Reserve as the research object,the effect of soil moisture gradient changes on the spatial heterogeneity of vegetation and soil properties in the reserve was studied,and the spatial variation trends were analyzed in order to provide a scientific basis for the research and protection of plant diversity in the reserve.[Methods]A mechanical sampling method was used,and three transects were established perpendicular to the lakeshore on both the northern and southern sides of the reserve,and the spatial distribution characteristics of plant communities and their soil physicochemical properties at different distances from the shore of the lake were analyzed.[Results]① With increasing distance from the lakeshore,the plant community shifted from the halophyte community to the psammophyte community,and the plant diversity index first increased and then decreased,reaching its maximum at 100-150 m.The bulk density,soil moisture content,electrical conductivity,and total porosity of Achnatherum splendens and Artemisia ordosica communities gradually decreased with increasing distance from the lakeshore.② With increasing distance from the lakeshore,the soil moisture content and electrical conductivity decreased markedly across different soil layers.Soil moisture content decreased by 10.79％,10.09％and 7.67％in 0-10,10-20,and 20-30 cm,respectively.Electrical conductivity decreased by 35.73 μS/cm,34.20,and 32.63 μS/cm respectively.③ Correlation analysis showed that plant diversity was significantly correlated with soil moisture content,electrical conductivity,total potassium,and clay content.Among them,soil moisture content showed the strongest correlation with Simpson and Shannon-Wiener indices,and the correlation coefficients were equal,with a value of-0.65.The main driving factors of plant diversity showed obvious spatial differentiation:within 0-50 m from the lakeshore,plant diversity was mainly affected by soil moisture content,soil organic matter,and total potassium.At 50-150 m,electrical conductivity was the dominant factor.At 150-200 m,soil moisture content and electrical conductivity jointly became the key factors influencing the distribution of plant diversity.[Conclusion]Under the influence of the lake,the reserve exhibits a significant soil moisture gradient,and vegetation types and soil physicochemical properties show significant spatial differentiation characteristics driven by this gradient.