Site Classification And Site Quality Evaluation Of Natural Secondary Forest In Hebei Province

Effective forest site classification and site quality evaluation are the basis of forest vegetation restoration and silviculture.Based on the analysis of the forest resource inventory data in Hebei Province,the main factors affecting the growth of trees were selected,and the site classification system of Hebei Province was established to evaluate the site quality of the main natural secondary forests in Hebei Province.The results are as follows.1)Based on Zhan Zhaoning’s site classification theory,combined with the natural conditions of Hebei Province and 3S technology analysis,the forest land in Hebei Province is divided into two site regions,three site areas and six site sub regions.And according to the different site sub regions,combined with the main site factors,the site type area,site type group and site type were divided.Based on the analysis of succession communities of different tree species,the stands with similar growth process were divided into a group,and seven types of stand growth types were classified in Hebei Province.Stand growth types included coniferous slow pure forest,coniferous fast pure forest,broadleaf slow pure forest,broadleaf fast pure forest,coniferous mixed forest,coniferous broadleaf mixed forest and broad-leaved mixed forest.2)Five growth models including Richards,campitz,logistic,kolf and monomolecular growth models were selected.According to the correlation coefficient,the model parameters with reasonable biological explanation were selected for guiding curve analysis.The results showed that Richards model was the best for coniferous slow pure forest,coniferous fast pure forest,and broadleaf slow pure forest.Campiz model was the best for broadleaf fast pure forest.The results of correlation test for site form table of different stand growth types were qualified,which indicated that it could be applied in forestry production.3)The site quality evaluation of natural secondary forest showed that the site quality of pure forest-coniferous pure forest-coniferous slow forest was the best in the site type of middle mountain-shady aspect-sandy soil-middle soil thickness.The stand growth type of pure forest-coniferous pure forest-needle fast grew better in middle mountain-sunny aspectloam site type and Hebei Bashang plateau.The site quality of pure forest-broadleaf ure forest-broadleaf slow growth was better in middle mountain-shady aspect-loam site type,Bashang plateau,as well as middle mountain shady aspect,and sunny aspect site type.The stand growth type of pure forest-broad-leaved pure forest-broad-leaved fast was distributed in all site subregions of Hebei Province,and grew well.