Study On Types Of Forest Structure Of Duj Iachong In Changsha

Taking Du Giachong forest farm in the four kinds of typical forest types: liquidambar formosana plantations, pinus elliottii plantation, schima superba forest plantation and natural secondary forest needle as the research object, with the stand structure management research and the method as the theoretical basis, through the different forest types of standard sample to field survey, analysis of survey data, and different forest types in forest stand structure characteristics were studied. Application size order number distribution histogram, Weibull distribution function and fitting inspection method, analyzed the diameter structure characteristics of different forest types. Use of bringing layer coverage, height, halosols deserts layer, species richness and plant diversity evenness of spatial structure parameters, analyzes the characteristics of different types of forest plant diversity. Using mixed Angle, Angle of scale, size score three spatial structure parameters, analyzes the four kinds of forest tree species segregation degree, level degree distribution and the size of the individual differences. And on this basis, put forward the four forest types structure optimization adjustment of business strategy. The main content of this paper include:different forest types of the laws of the spatial structure and spatial structure research. The results showed that:(1) the law of stand spatial structure research results show that the look from the diameter class distribution structure, liquidambar formosana plantations and mixed needle leaf and more focused on the trail order in the forest trees, large diameter trees rarely. The trees of pinus elliottii plantation and schima superba forest plantation order more focused on the pitch diameter of trees, forest stand level there is a certain proportion of big diameter trees. Plantation forest structure the J type are not obvious, and the distribution of the structure is close to normal distribution. Needle mixed with a few samples of the stand structure has a tendency to close to the J type. Liquidambar formosana plantations and mixed needle leaf and fitting effect is good, schima superba and pinus elliottii plantation plantation are part of the sample to the phenomenon of poor fitting effect.(2) from the point of plant diversity, mixed needle leaf and diversity index is higher than the plantation. In plantation tree layer, liquidambar Lin has the highest richness index, the highest wetland pine forest plant diversity index, schima superba forest have the highest species evenness index. In plantation shrub layer, the diversity index of pinus elliottii plantation> liquidambar formosana plantation> schima superba forest plantation. In herb layer in the plantations of pinus elliottii plantation of highest richness index and Shannon Wiener diversity index, species evenness index of liquidambar formosana plantation is the highest. Four forest types, liquidambar formosana plantations, mixed pinus elliottii plantation and needle halosols deserts layer continuity is better, the horizontal and vertical distribution of schima superba plantation horizontal and vertical distribution of poor continuity, the lowest diversity index.(3) the research results show that the regularity in the stand spatial structure: look from the spatial distribution pattern of trees, pinus elliottii plantation and the mixed needle leaf and shows the characteristics of random distribution, the average Angle scale were0.483and0.480; Liquidambar formosana plantation was0.543belong to the group distribution; Belong to uniform distribution of schima superba plantation was0.431. From the kind of isolation between mixed average0.678for the mixed degree of intensity is mixed; Schima superba forest plantation was0.441, for moderate mixed state; Liquidambar formosana plantation was0.355for moderate weak mixed; Pinus elliottii plantation was0.289to weak degree mixed state. From the tree size differentiation degree, the diameter of the liquidambar formosana plantation size score0.514; Pinus elliottii plantation was0.489; Schima superba forest plantation was0.441; Mixed needle is0.502. Each stand diameter size score distribution is relatively uniform, growth basically in a state of the doctrine of the mean.(4) for different forest types of the research results show that the structure optimization and adjustment of stand diameter class structure level should make its diameter curve tends to show the distribution features of inverted J. Forest diversity, adopt scientific and effective adjustment measures and countermeasures of management, to the optimum of the tree to build mixed needle is tie-in, create a richer, more complex and stable structure, species has good forest biodiversity. Spatial structure optimization adjustment, analyze the Angle of scale, mixed degree and size numerical score of three parameters, the reasonable filter unit needs to adjust the structure of the trees, using reasonable measures, make the stand level distribution pattern is in random distribution condition, and create a high degree of species mixed, trees, update strong, uniform structure of forest health.