Health assessment of Picea classifolia forest in the Dongdahe forest region

Based on field survey data during 2008,the principal component analysis,cluster analysis and model of health assessment were used to assess the health state of Picea classifolia in the Dongdahe forest region by establishing the health indicators system,which included 19 indicators belonging to five strategy layers,and they were natural environment,community characteristic,stand resilience,productivity and potentialities.This study showed that the principal indicators affecting the health state of P.classifolia forest were community type,canopy closure,shrub coverage,stand volume,soil hygroscopic water,and soil moisture content.The assessment results indicated that the 13 sample plots were divided into health,sub-health and poor health.The health sample plots were 7 and were moss P.classifolia forest,accounting for 53.82%;the sub-health included one moss P.classifolia forest and three herb P.classifolia forests and they accounted for 30.77%;and the poor health plots were 2 shrub P.classifolia forest and accounted for 15.38% of total area.