黄丘区植被恢复过程中土壤团粒分形特征及抗蚀性演变

Research on the Fractal Features of Soil Aggregate,and Dynamic Changes in Anti-Erodibility during the Process of Vegetation Recovery on the Loess Hilly Areas

为了探讨植被恢复过程中生态环境变化对土壤团粒结构及土壤抗蚀性能产生的影响,在野外调查与室内分析的基础上,研究了黄土丘陵区植被恢复过程中土壤水稳性团粒结构的分形维数变化规律,分析了其与土壤养分状况、土壤结构稳定性以及土壤抗蚀性能的关系。结果表明,土壤团粒结构的分形维数与土壤容重、结构体破坏率和MWD呈极显著正相关,与土壤可蚀性K值呈显著正相关关系,与孔隙度、有机碳、有效氮呈显著负相关,与全氮、全钾呈负相关关系,但不显著,与全磷和速效磷相关性较小。说明随着植被恢复,土壤结构得到明显改善,抵抗侵蚀的能力显著增强。土壤团粒结构的分形维数可以作为土壤抗蚀性评价的指标之一。

In order to discuss the impacts of eco-environment changes on the soil structure and anti-erodibility during vegetation recovery,this paper deals with the fractal characteristics of soil water-stable aggregates during the vegetation recovery process in the loess hilly plateau and analyzes the relationship among soil nutrient,soil structural stability and anti-erodibility based on the field investigation and lab analysis.The results show that fractal dimensions of soil water-stable aggregates are significantly positive correlated with bulk density,soil structural destruction ratio and MWD,dramatically positive correlated with soil erodibility K values,negatively correlated with porosity,soil organic carbon and available N,and with total N and total K but less significance,and little correlated with total P and available P.The results indicate that the soil structure and anti-erodibility are greatly improved during the vegetation recovery.The fractal dimensions can be used as one of the indexes for the assessment of soil anti-erosivity.