典型黄绵土团聚体稳定性变化对植被演替的响应

Response of Soil Aggregate Stability Changes of Typical Huangmian Soil to Vegetation Succession

摘要:

本文选取黄土高原子午岭林区4种植被演替阶段(草地、沙棘、山杨和辽东栎)的土壤作为研究对象，以农田土壤为对照，采用高能水分特性法测定不同植被演替阶段下的土壤团聚体稳定性，探究其变化特征以及响应因子。结果表明：表层(0~15 cm)土壤团聚体稳定性指数(SR)表现为草地(0.43)<农田(0.46)<沙棘(0.49)<山杨(0.59)<辽东栎(0.70)，亚表层(15~30 cm)土壤SR则表现为农田(0.36)<草地(0.46)<辽东栎(0.52)<沙棘(0.65)<山杨(0.68)。整体上随着植被的正向演替，土壤团聚体稳定性不断增强，表层土壤团聚体稳定性不完全高于亚表层。除土壤有机碳外，团聚体稳定性与土壤粒径组成的关系同样密切，其中有效砂粒为土壤团聚体稳定性最主要的响应因子。

Abstract:

In this study, soils at four stages of vegetation succession (grassland, seabuckthorn, poplar and Liaodong oak) in the Ziwuling forest region of the Loess Plateau were selected as the research object, with the farmland soil as the control (CK). The high energy moisture characteristic (HEMC) method was used to determine soil aggregate stabilities under different vegetation succession stages, and explore the change characteristics and response factors. The results showed that surface (0-15 cm) aggregate stability index (SR) showed grassland (0.43)<farmland (0.46)<seabuckthorn (0.49)<poplar (0.59)<Liaodong oak (0.70), while subsurface soil (15-30 cm) SR was farmland (0.36)<grassland (0.46)<Liaodong oak (0.52)<seabuckthorn (0.65)<poplar (0.68). On the whole, with the vegetation succession, the stability of soil aggregate was constantly enhanced, and the stability of surface soil aggregate was not completely higher than that of subsurface. Besides soil organic carbon, aggregate stability was equally closely related to soil particle size composition, with effective sand grains serving as the most important response factor for soil aggregate stability.