Study On Structure Adjustment And Optimization Of Larix Gmelinii

In this paper,the forest of Larixgmeliniiforest in Daxing'anling Mountain area in Inner Mongolia,is taken as the research object.By collecting data from the sample field survey,the forest structure characteristics of the research object are analyzed.And the SPSS software is used to fit the actual stand diameter structure with negative exponential distribution function,and the size of the mixed degree and the size of the DBH is used by the Winkelmass software.The spatial structure of the realistic stand is analyzed by three aspects of the ratio and the angle scale.Finally,according to the existing problems of forest stand structure,corresponding structural optimization and adjustment measures are put forward.The results of the study show that:1.The curve of the diameter structure of the original forest presents an inverted "J" curve.The tree number distribution of the stand diameter of the successive cutting forest and the clear cutting forest is the peak mountain shape,the R value of the original forest is 0.969,the fitting result is relatively ideal,and the R value of the gradual and clear cutting forests is relatively low,and the fitting effect is poor.2.From the mixed degree,the spatial isolation degree of three forest types is in weak mixed state,and the mixing frequency is 0.366,0.112 and 0.333,respectively.From the aspect of DBH size ratio,the mean DBH size ratio of the three stands is close to 0.5,and the growth is in the golden mean.From the angle frequency distribution,the original forest belongs to the random distribution state.The average angle scale is 0.505,between 0.475 and 0.517.The average angle of the gradual and clear forest is more than 0.517,and it is a cluster distribution(mass distribution).3.Finally,taking the original forest as the target structure,the following optimized adjustment measures were put forward: the tree species composition in the stand was 7:3,the structure distribution map of the stand diameter should show an inverted "J" curve,and the q value interval should be between 1.2 and 1.5.In the stand spatial structure,the frequency of mixed degree should be adjusted to more than 0.3,and the higher the frequency,the bigger the DBH size ratio should be.The distribution pattern of stand should be random distribution state,and the average angle scale is based on the effective interval [0.475,0.517].Finally,the aim of optimizing the structure of the stand is realized in the form of logging single wood,that is,the cutting method is single plant selective cutting.4.Through the study on the structure characteristics of the Larix larix forest stand in Daxing'anling Mountain area,according to the characteristics of the present structure of the stand,the rational adjustment and adjustment measures for the stand structure and the reasonable scientific theoretical basis are provided in the practical operation,and it is of practical significance to the optimization of the forest structure in this area.