安徽省大别山区上舍小流域植被根系与土壤抗冲性研究

Relationship between plant system root and soil anti-scourability in the Shangshe catchment,Dabie mountains of Anhui Province

采用标准地调查方法，对大别山区上舍小流域不同植被类型根系，在0～40cm土壤深度范围内按照10cm间隔分层采样，室内测定不同径级（〈0．5，0．5～1．0，1．0～2．0和2．0～5．0mm）根系生物量和根系长度，同时在各标准地根系相似地段内，采用C·C·索波列抗冲仪，在0～40cm深度范围内按照10cm间隔分层测定土壤的抗冲性。结果表明：植被根系主要分布在0～40cm土层内，表土层根量最大，根径〈1．0mm的细根在根长上占有绝对优势；同一植被类型表土层土壤抗冲能力大于心土层；植物根系，尤其是根径〈1．0mm的细根具有较强的固持土壤功能，细根长、根质量、根密度与土壤抗冲指数之间的相关系数分别为0．8173、0．7159和0．5434，可知，细根长是影响土壤抗冲性的关键因子；不同植被类型土壤的抗冲性与土壤非毛管孔隙度具有很高的相关性，表明森林植被的固土功能是通过根系改善土壤的物理性质，创造具有抗冲能力的生物土壤复合体结构实现的。

The distribution of root biomass was studied in different layers （0 - 10 cm, 10 - 20 cm, 20 - 30 cm, 30 - 40 cm） of soil depth with the plot method in different types of plant in the Shangshe catchments in the Dabie Mountains of Anhui province. Samples of root system were taken to the lab to measure their quantity and length. In each plot, soil anti-scourability in corresponding soil layer was measured with a C.C. Suoboliev anti-scourability instrument. The results showed that ： 1 ） the root system was mainly distributed in 0 - 40 cm layer of soil, and the root quantity was the biggest in surface layer of soil. The fine root less than 1 mm in diameter was absolutely predominant in root length. 2） In the same section, the values of anti-scourability index of surface layer were larger than those of other layers in different types of plant. The tree root system, especially the fine root less than 1 mm in diameter had powerful function on soil loss control. The correlated coefficients between the length, quantity, density of fine root and anti-scourability index were 0.817 3, 0.715 9 and 0. 643 4 respectively. The length of fine root was a key factor to soil anti-scourability index. Anti-scourability index was closely correlated with non-capillary of each different type of soil, indicating that forest had a soil-stability function because their root system improved soil physical properties and finally created a bio-soil system with anti-scourability.