<正>针对采用SPOT5卫星影像进行森林资源调查后，小班植被因子无法直接判读的问题，通过分析研究森林资源遥感调查和林业专业调查数据，提出了在遥感调查中各小班植被因子的自动提取方法。将此方法提取的因子与实地调查因子作对比，结果表明，幼树种类的一致率为86%，下木种类的一致率为92%，草本种类的一致率为96%。

Based on the amount of samples data with 5 factors such as community type,arbor and shrub coverage,biomass, community height and litter amounts using methods of principle components analysis and clustering analysis, the results indicated that the forming process of rocky desertification could be divided into 4 stages: initial stage,mid-stage,last stage and the end stage. Analyses on forming process and stage characters showed that the main reason of land system degraded in forming process of rocky desertification was degradation of vegetation sub-system, caused by human disturbance on the degradation of soil sub-system and micro-climate environment sub-system. A positive feedback was formed of mutual cycle and interaction among each sub-system. The degradation and losing of land productivity were essential of rocky desertification forming process.