基于植物群落结构的水土流失植被因子指数研究

通过分析传统生态学盖度在指示植被防止水土流失功能的不足,以植被垂直结构中各个层次控制水土流失的机理为依据,提出结构化植被因子指数Cs这一新的指标,建立了植被因子指数模型并进行了案例分析。结果表明:油松和山杨群落中,林冠层、草被层及枯枝落叶层都是植被防止水土流失的关键层次,其盖度对于防止水土流失的作用权重分别为0.0150,0.591,0.394和0.0608,0.828,0.112。结构化植被因子指数考虑了群落结构中各层次的相对作用,并结合各层次的盖度来综合反映植被影响水土流失的作用,比传统的生态学盖度能更好地描述植被与土壤侵蚀的关系,是一种理想的植被因子指标。

Research on Soil Erosion Vegetation Factor Index Based on Community Structure

Vegetation is one of the important factors affecting soil and water loss,thus is regarded as one of the key parameters of soil erosion prediction.It's well known that the vertical structure of vegetation is composed of different layers and each layer has different impact on soil erosion,yet the traditional coverage cannot reflect the impact of different layers on soil erosion,and sometimes overestimate or underestimate the impact of vegetation on soil erosion.With the consideration of this fact,a new vegetation factor index Cs,structured vegetation factor index,was proposed and the vegetation index factor models have been established using multiple regressions in this paper.The case study in the locust tree and the Chinese pine communities showed that tree layer,herb layer and litter layer are important to prevent the soil erosion and their weights are 0.0150,0.591,0.394 and 0.0608,0.828,0.112 respectively for the Chinese pine and the aspen communities.Structured vegetation factor index,which considering the relative roles and coverage of each layer in the vegetation communities,could be better than traditional coverage in describing the relationship between vegetation and soil erosion.This could be an idealized indicator and have great significance for both soil erosion evaluation and prediction and the vegetation constructions for soil and water conservation.