Research On Forest Health Evaluation Of Larix Gmelini In The Great Xing'an Mountains

This dissertation is based on the demonstration project of soil loss control(forest health) by biological measures sponsored by State Forestry Administration-Forest Health demonstration project in Tahe Forestry Bureau.Taking Tafeng management site of Tahe Forestry Bureau as the main study area, forest health evaluation index system was established to study the main forest health influence factors in this area according to the fundemental theory and the latest research progress by taking site investigation,data analysis,statistical analysis and AHP method.At the same time,forest health monitoring and control are implemented based on evaluating and analyzing the forest health status.Based on the actual situation of study area and combining with the indicators system for forest health observation of forest ecosystem published by State Forestry Adminstration,the ordinary indicators system for Larix gmelini Forest monitoring and assessment was proposed.The indicators system is divided into 6 class 16 indexes.And also an AHP evaluation model was established.The status of forest health is divided into 4 grades:health,sub-health,general health and poor health.The result of AHP evaluation shows that the analogy sorting of main influence factors of Larix gmelini Forest Health in this area is:forest fire,occurrence and damage of forest pests,forest soil erosion condition,human disturbance,occurrence and damage of forest rodent,biodiversity,pollution effect on the forest;the indicators sorting is:density of forest barrier zone,coverage of ground cover, insect density,gradient,percentage of harmed plants,human cutting-area,rodent damage area,vegetation coverage,diseases and insect pests species,tree species composition,attracked trees rate,human cutting intensity,shrub species,damaged forest area,ground cover species,artificial renewal trees number.The evaluation result to the four kinds of Larix gmelini Forest communities shows that:the grade of Herbage Larix Forest is sub-health and the other 3 types are all general health.So it is necessary to select effective measures such as improving forest structure and forest management to promote forest health management in this area.The forest health of 2-stage evaluation for Larix forest community based on forest subcompartment shows that:the forest health status has advanced and improved in some degree.In order to promote forest health management,further study on the 2 main influence factors:forest fire,forest pest and rodent is done;directed monitoring and evaluation factor and standard for each pest and rodent species are established;the relationship between forest fuel factor and forest type is analyzed and relation model is established and the result shows that the fuel factors have significant correlation with main forest type indictors.Forest Health Monitoring System of this area is established on the basis of evaluation.5 monitoring sample plots are setup in the project area.The plot monitoring is selected as monitoring method.Ground plot monitoring and investigation is the main method.At the same time,the control measures for improving forest health management is discussed in the paper.