Assessment On Forest Health Of Larix Principis-rupprechtii Plantation In North Mountain Of Hebei Province

To achieve improved forest structure, improved forest productivity, species diversityand enhanced ecological function by forest management, is an important goal of forestmanagement. So the construction of forest health assessment index system and the choiceof forest health assessment method, which can effectively reflect the effect of forestmanagement measures, have important theoretical and practical significance on enhancingand optimizing forest management technology system.Larix principis-rupprechtii plantation is one of main forest type in North mountain ofChina. The health state of Larix principis-rupprechtii plantation not only has greatinfluence on the ability of water conversation, air quality, but also on the local financialrevenue. Taking the40year-old Larix principis-rupprechtii plantation with differentmanagement measures in Longtoushan forest farm as the objective, this paper built upforest health assessment index system and evaluated the forest health by using the methodof principle component analysis and correlation analysis, analyzed the impact ofmanagement measures on forest health condition. According to forest health evaluationresults, we conclude the main factors and proposed advices for optimizing forestmanagement technical measures. The main results are as follows:Combined with stand characteristic of Larix principis-rupprechtii plantation andseveral different management measures, this paper selected11indexes from forest growth,structure, regeneration, species diversity and soil condition to construct the forestecosystem health assessment index system, which can reflect changes of forest healthstatus.11indexes are volume annual increment, DBH annual increment, communityhierarchy, the size diversity index of DBH, diversity index of shrub, diversity index of herb,density of natural regeneration, the species number of natural regeneration, the survivalrate of artificial regeneration, soil bulk density, soil moisture content respectively.The results of forest health evaluation showed that the stand health status would bedifferent between different management measures. Among16plots,6plots are health,5sub-health plots, and5poor health plots. Forest health evaluation presented the order ofmanual promote renew2> gap selection cutting manual promote renew1> banding clearcutting> manual promote renew3> closed promote vegetation>unprotected area. Compared with forest health assessment results of2007, increment of differentmanagement measures (gap selection cutting, manual promote renew4, manual promoterenew1, manual promote renew2) are129.59%,118.49%,117.89%and112.29%respectively.Based on the results of principal component analysis and correlation analysis, wefound that the survival rate of artificial regeneration, DBH annual increment, diversityindex of herb, the number of natural renew and the size diversity index of DBH aresignificantly related to forest health index respectively. In addition, diversity index of shruband forest health index are positively correlated to some extent.According to health status of Larix principis-rupprechtii plantation of study area,combined with the main factor affecting on the forest health, several suggestions areproposed to in order to build a healthy and stability ecological and economic forest, whichcan give full play to its social, economic and ecological functions. First, take moreattention on human disturb and livestock damage. Second, strengthen artificial promoteupdate, appropriate introduction of broadleaf trees and native shrubs can be taken toimprove species diversity of stand. Third, according to the characteristic of forest type andmanagement measure, we should put forward scientific tending harvesting policies toprovide protection for forest health growth.