紫色土典型植被类型表层土壤团聚体稳定性差异分析

Analysis of Difference in Surface Soil Aggregate Stability of Typical Vegetation Types in Purple Soil

  • 摘要: 在三峡库区腹地忠县秦岭小流域内,选取柏树、马尾松、桉树、柑橘、灌木、草地和玉米7种典型植被类型,探究不同植被类型土壤团聚体稳定性差异,分析导致这种差异的影响因素。结果表明:不同植被类型>0.25 mm土壤大团聚体含量(WSA>0.25)、团聚体平均质量直径(MWD)和几何平均直径(GMD)为27.12%~91.79%、0.71~5.61 mm和0.25~4.00 mm,玉米地的平均WSA>0.25、MWD和GMD均为最小,灌木地(黄荆)均为最大。土壤团聚体稳定性受土壤性质和植被特性综合影响,WSA>0.25、MWD和GMD与土壤有机质含量呈极显著正相关,WSA>0.25与根系质量密度、MWD与枯落物蓄积量呈显著正相关,但WSA>0.25、MWD和GMD与土壤有机质含量、枯落物蓄积量和根系质量密度表现为对数函数增大。冗余分析结果表明,不同植被类型土壤有机质含量、黏粒含量和枯落物蓄积量的差异是导致土壤团聚体稳定性差异的主要影响因素。

     

    Abstract: In the Qinling small watershed of Zhongxian County, situated within the hinterland of the Three Gorges Reservoir region, 7 representative vegetation types of Cupressus funebris, Pinus massoniana, Eucalyptusspp., Citrus reticulata, shrub, grassland and maize were selected to examine the variations in soil aggregate stability across different vegetation categories and to analyze the factors influencing these variations. The result showed the content of soil aggregates >0.25mm (WSA>0.25), mean weight diameter (MWD), and geometric mean diameter (GMD) varied from 27.12–91.79%、0.71–5.61 mm and 0.25–4.00 mm among different vegetation types. And maize land had the minimum mean WSA>0.25, MWD and GMD, whereas shrubland of Vitex negundo had the maximum ones. The stability of soil aggregate is comprehensively affected by soil properties and vegetation characteristics. The WSA>0.25, MWD and GMD were significantly positively correlated with soil organic matter content, WSA>0.25 was significantly positively correlated with plant root mass density, and MWD was significantly positively correlated with plant litter accumulation. However, WSA>0.25, MWD and GMD increased logarithmically with the increase of soil organic matter content, litter accumulation, and root mass density. The result of redundancy analysis showed that soil organic matter content, clay content, and plant litter accumulation were the main factors attributing to the differences in soil aggregate stability.

     

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