| Eucalyptus is one of the three largest planted forest species in the world.It has the advantages of rapid production,tolerance to barren and wide use.It has now become the main afforestation tree species for fast-growing and abundant forest and industrial raw material forest in the south of China.However,with the development of eucalyptus plantations,its ecological and economic benefits have become more and more important.How to put forward reasonable management reform measures to improve the quality of forests and realize the precise improvement of forest quality has become the focus of today's eucalyptus plantation research.At present,the research on forest quality of eucalyptus plantation is mainly reflected in the research on quantitative indicators at home and abroad,and there is no common theory for comprehensive research on forest quality of eucalyptus plantation.Therefore,comprehensive research on forest quality evaluation of eucalyptus plantation is necessary.Based on this,this study puts forward the concept of "Stand quality index",which is a comprehensive index that is used to reflect the differences in the evaluation of forest quality in different forest classification types.The value of the forest score mass index is[0,1].The greater the value,the better the forest stand quality.The Giant Eucalyptus plantation in Leshan City of Sichuan Province was selected as the research object.In this research,the data of 14,296 large tail trees in Leshan were analyzed.Through the analysis,a total of 15 evaluation indicators were selected:age group,forest density,tree stock per area,average chest diameter,average tree height,soil thickness,humus layer thickness,gravel content,slope,slope direction,elevation,forest accessibility,community structure The degree of integrity,the proportion of dominant tree species,and the degree of forest health,and the use of the principal component analysis method to analyze the correlation factors affecting each forest quality,extracted three common factors,and summarized them as forest growth status,forest quality,and forest stability.It constitutes the standard layer and index layer of the forest quality evaluation system;The expert scoring method and analytic hierarchy method are used to assign weight to each evaluation index.Based on the comprehensive scoring method,the comprehensive evaluation value of the forest quality of each giant eucalyptus plantation was obtained,namely the "SQI";Finally,on the basis of this,the forest quality classification was carried out on the artificial forest of Leshan Juwei in Sichuan Province,and it was divided into five grades:excellent,good,medium,poor,and inferior.Different management and renovation measures are adopted for small classes in different grades of forest land to achieve the purpose of adjusting forest structure,improving forest ecological service functions,and improving forest quality in order to achieve the precise improvement of forest quality.The results show that the quality of the forest stands is not high,and the number of forest stands with better quality is very small.Among the factors affecting the quality evaluation of the forest stands of Eucalyptus huowei in Leshan City,Sichuan Province,the growth status of forest stands has greater influence than the quality and stability of forest lands.According to the statistical results of the stand quality index value,the stand quality index was used to classify the quality of the artificial forest of the giant eucalyptus in Leshan City.The classification results were:[0.1172,0.1999]Between the inferior,[0.2000,0.3999]Between the difference,[0.400.5599]Between medium,.0.6000,0.7999]Between good and good,[0.8000,0.8459]Between the excellent.Based on the statistical results of the comprehensive evaluation of forest quality,the number of small forest classes with poor forest quality in the forest of the giant tail of Leshan City was 2,136,accounting for 14.96%of the total number of forest land in the artificial forest of the giant tail;There are 8767 small forest classes with poor forest quality,accounting for 61.32%of the total number of forest lands in the giant forest;There are 2,419 small forest classes with medium forest quality,accounting for 16.92%of the total number of forest lands in the giant forest;There are 716 small forest classes with good forest quality,accounting for 5%of the total number of forest lands in the giant forest;There are only 258 small forest classes with superior forest quality,accounting for 1.8%of the total number of forest lands in the giant forest.The quality of forest distribution reflected in the assessment results is consistent with the real situation of forest resources in the research area,and at the same time meets the requirements of "accurate improvement of forest quality",which can provide theoretical and technical support for the accurate improvement of forest quality in Leshan City,Sichuan Province.At the same time,since the evaluation indicators used in the forest division quality index system are all general contents in the forest division survey,it is easy to obtain data through small class measurement and sample survey,and it is also convenient to determine the range of evaluation values for each evaluation indicator.From this,The evaluation method and index system can be used to evaluate the quality of artificial timber forests in other areas of Sichuan. |
PDF Full Text Request