水分梯度下高寒草甸草丘分布引起植被生境的空间变化OA

In alpine meadows,the surface soil heaves to form hummocks under the influence of frost heaving,transforming the originally relatively homogeneous habitat into a heterogeneous one.In this study,9 sampling plots were established along a soil moisture gradient in the alpine meadows of the Western Sichuan Plateau.We compared and analyzed the differences in plant communities and species diversity between hummocks and inter-hummock meadows under different soil moisture conditions.The results showed that:Soil physical properties and soil chemical properties exerted effects on the plant diversity of hummocks and inter-hummock meadows,respectively.The plant community on hummocks gradually transitioned from Kobresia(sedge)-dominated veg-etation to shrub-dominated vegetation,while the plant community in inter-hummock meadows gradually shifted from Carex(sedge)and Kobresia-dominated vegetation to grass-dominated vegetation.The abundance of weedy plants and occasional species in hummocks was significantly higher than that in inter-hummock mead-ows.Habitat aridification increased the dissimilarity in species composition between hummocks and inter-hum-mock meadows,and the dissimilarity in species composition of hummocks was higher under different soil mois-ture conditions.In conclusion,hummocks tend to aridify the microhabitat and provide favorable conditions for the invasion of occasional species.Although hummocks increase plant diversity,they have a negative impact on the stability of alpine meadow vegetation.This research holds significant implications for guiding the conserva-tion and management of alpine meadow vegetation.