Forest Health Evaluation For Conifer And Broad-leaved Forest At Different Successional Stages

Because of the rapid development of social economy, people are changing and influencing the ecological system at a fast speed, among of them, the destruction of the forest ecological system is the most obvious, forest area dropped from 7.5 billion hectares to 3.2 hectares. In the early 1880s, the German forestry administrations put forward the concept of forest health, and then the decline and reduce of forest captured people’s attention, it turned people to work for protecting forest.The article summarize research status of forest health and assessment firstly, introduced the origin of forest heath’s concept and three characteristics of it detailedly, what’s more, the characteristic of forest heath will become different when the purpose of research changed. The object of study are middle-aged forest, nearly mature forest, mature forest and old-growth forest, which at different successional stages of mixed conifer-broadleaf forest in Jiaohe forestry experimental region in Jilin province, finally, by establishing the evaluation index system and confirming weight to get their health index, and then determining their status. After reading a lot of domestic and overseas literatures, taken Contanza’s VOR model(productivity V, organization O, resilience R) as reference, and taken example by Li Xiuying’s indicator system, joined the index of soil quality S to build the VORS model,which is new, and formed a indicator system of the forest for Jiaohe forestry. Due to the forest soil health assessment is the base of the forest health assessment, so analyzed it mainly, and used membership function and analytic hierarchy process to calculate. Result showed that:grade of the whole area is medium. The species richness, species diversity, species evenness, and dominance indices were computed. ANOVA analysis and Duncan’s multiple-range test were conducted to compare the differences of the indices among different forest communities. Results is Margalef index、 Shannon-Wiener index、Pielou index and Simpson (Gini) index。After obtained the value of indexes, throughed the factor analysis method of SPSS software to extract the effective factors, it can reduce forest health evaluation index dimension and repetitive information of index, finally, used factor contribution rate formula to calculate the weight factors, the result showed that:mature forest is health, nearly mature forest and old-growth forest is sub-health, middle-aged forest is ill-health.