Study On The Stand Structure Regulation Of Natural Secondary Forest In The Laotudingzi Natural Reserve

In this study, the Natural Secondary Forest in the Laotudingzi Natural Reserve as the object of study, the use of structured forest management theory, its dominant populations in the composition, diameter distribution and spatial structure analysis, structural adjustment study based on the analysis of the results of the dominant tree species. The main findings are as follows:(1) Study area the Laotudingzi Natural Reserve Natural Secondary Forest tree layer species has16main tree species, according to the number of trees ratio analysis, aspen, maple, Mongolian oak and birch as the dominant species occupied the absolute proportion, basal area analysis by aspen, Mongolian oak, maple and birch the dominant species.(2) Bands the number of trees of diameter class for each forest type showed that the forest stand density of stand Ⅰ and stand Ⅲ are smaller, trees tend to concentrate on the large-order trees, it’s not conducive to the stand development and succession in the future. Diameter class-strains curve presents take on multimodal. The forest stand density of stand Ⅱ, stand Ⅳ and stand Ⅴ are larger, trees tend to concentrate on the trail-order trees, growth is poor. Diameter class-strains curve presents take on anti-"J". Fitting five stand with negative exponential distribution, only stand Ⅱ and stand Ⅴ diameter structure are rational distribution, q value is less than1.7and greater1.2. Stand Ⅱ, stand Ⅲ and stand Ⅴ the three kinds of forest types in the hierarchy above level2, layered more obvious, and five kinds of forest types natural regeneration is good or medium.(3) In addition to stand Ⅱ belongs to group distribution, the other four forest types belong to the random distribution. The advantage of top trees of stand Ⅱ less than0.5, don’t occupies a dominant position in the stand competition. The other four stands, the advantage of top trees are greater, at a advantage in the competition average mixed forest. The average mingling of stand Ⅳ is0.75, belonging to intension moderate mixed forest. The average mingling of the other four stand are greater than0.5, basically between the moderate and the intension mixed forest. Comprehensive analysis, five kinds of forest types in spatial distribution characteristics of good, most of the index value is within a reasonable scope.(4) On the basis of the stand spatial structure, adjust the management structure of different age, stratified, mixed forest as the final goal, create the best stand space structure as the key point, using the structured forest management methods to adjust the Natural Secondary Forest’s horizontal distribution pattern, composition of species and competitive relationship, and also evaluate the effect of management results in many ways. The evaluation showed that, through the adjustment of community structure, the nutrition space of the remaining trees has increased and the competitive pressures have reduced, creating a good environment for the growth of the remaining trees.