Construction Of The Index System For Assessment Of The Forest Health Mainly On Disease And Insect Pests

Forest health is a status of forest ecological system that not only can maintain its diversity and stability, but also can fulfill the natural, social and economic requirements of human on forest continuously. Healthy forest is recoverable, which means that forest is able to recover to the initial level when interfered by human or nature.At present forest can’t satisfy people’s needs due to the influence of artificial and natural factors, so the idea of forest health management arises at the historic moment. The forest health assessment is the premise of the forest health management and the establishment of index system of assessment is its key procedure. At present the index system of assessment of forest health rarely involve concrete forest disease and pest evaluation. Based on referring to other research results, the main indexes and key factors are selected in this article forest health evaluation index system is summarized, which is operational mainly on disease and insect pests. The main indexes and key factors were selected. The research results are as following:1.According to forest types, hierarchy, plant diversity, insect diversity, degree of forest damage and other indicators, we combined the fuzzy comprehensive evaluation method and established the index system of assessment for forest health mainly on disease and insect pests. According to the different stand types, we came up with composite index for forest health mainly on disease and insect pests.The index is (?)2. Refined the indices of forest disease and pest part in forest health evaluation index system. Based on the classifications of Ecological Forest, Commercial Forest, in terms of the hazard position the pests were divided into defoliator, trunk borer, twig and shoot pests, seed pests, root (underground) pests. The disease was divided into stand tree rot, wood rot, leaf disease, twig and shoot disease, root disease. Each weight of the pest parts in Ecological Forest were0.22,0.33,0.14,0.08,0.23, and each weight of the disease parts in that were0.24,0.33,0.28and0.15. Each weight of the pest parts in Commercial Forest were0.21,0.37,0.13,0.10,0.19, and each weight of the disease parts in that were0.47,0.09,0.33and0.11;3. Three forest farms in Aershan Forestry Bureau were investigated through the weight table of timber forest and forest disease and pest degree. The Forest Health Comprehensive Index (HCI) of Chaihe Forest Center, Aershan Forest Center and Yiershi Forest Center were0.81,1.15and1.56respectively. With the high HCI in Yiershi Forest Farm, we could see that the forest original state was destroyed and it was in an unhealthy state. Beijing Ming Tombs forest demonstration area was investigated through the weight table of Commercial Forest and forest pests degree,and the HCI is1.00. As a result of single structure tree, cause forest pest resistance ability drops, disease and insect pests damage worse.Composite index of forest health changed with the degree of disease and insect pests. The assessment result showed that we could get the unanimous conclusion with this method and the health degree of the plots objectively.Assessment of pest and disease specific indicators has an important role in improving the entire index system of assessment of forest health. It can provide people with a relatively simple method to describe the importance of the forest disease and pests indexes in the whole assessment system.