Impacts of Different Vegetation Types on Soil Aggregate Stability in the Alpine Treeline Ecotone of Southeastern Xizang
The structure of soil aggregates is crucial for maintaining the stability and functionality of soil ecosys-tems.To explore the specific factors influencing soil aggregate stability across vegetation types such as trees,shrubs,and meadows within an unique region of the alpine treeline ecotone,this study focused on the alpine treeline ecotone of Juniperus saltuaria forests on the sunny slope of Sygera Mountains in southeastern Xizang.Employing the dry-sieving method,we investigated the composition of soil aggregates and the influence of soil physicochemical properties on aggregate stability under four vegetation types:Abies georgei var.Smithii for-ests,Juniperus saltuaria forests,Rhododendron nivale shrublands and meadows.The results showed that:Under all four vegetation types,the content of soil aggregates with particle sizes>0.25 mm was significantly higher than that of aggregates<0.25 mm.Soil aggregate stability in meadows and shrublands consistently sur-passed that in tree forests,with the lowest stability observed in the Juniperus saltuaria forest soil at the 0-10 cm soil layer and in the Abies georgei var.smithii forest soil at the 10-20 cm soil layer.The composition of soil aggregates was jointly influenced by multiple soil physicochemical properties,significantly impacting their stabil-ity.Specifically,lower soil pH,smaller bulk density,higher organic matter content,greater capillary water holding capacity,or higher porosity were associated with better soil aggregate stability.The results of this study provide data support for an in-depth understanding of soil quality and structure in high-altitude mountain-ous areas.
万方数据
维普
