| The larix forest of changbai mountain is an important habitat for the amur tiger and leopard.Based on the survey of permanent sample plots,this study made a multifunctional evaluation and offered multifunctional management suggestion to larix forest by combining theory with practice,combining qualitative judgment with ration and model,combining investigation in field with scientific analysis and reasoning.On the basis of 18 sample plots survey data,the characteristics of stand structure in different age stages of plantation and natural larix forests were analyzed.Based on the local requirement of economical and social development,the multifunctional requirements of larix forest were obtained,and the evaluation model between forest structure and function was proposed to evaluate the multifunctional status of larix forest from different ages and different origins,and to compare the relationship among different forest functions in this study area.The multifunctional management model of larix forest was put forward,which provides great theoretical and technical support to the management of larix forest in this area.It also offered the possibility to realize the society,economy,ecology benefits.The main research results are as follows:(1)In this study,the stand structure form different age stages and different origins were analyzed.The diameter distribution curves of larix plantation were left side single peak curve in half-mature stage,single peak curve in near-mature stage and mature stage.The curves of natural forest all were multiple peaks curves.The volume proportion of larix plantation of small,medium,big,extra diameter class in different age stages were 4:5:1:0,0:5:5:0 and 0:6:3:1,respectively;the volume proportion of natural forest of small,medium,big,extra diameter class in different age stages were 1:6:2:1,1:4:5:0 and 0:4:4:2,respectively.The mingling degree of plantation was weak in half-mature forest,but moderate or intensify in near-mature forest,and moderate in mature forest.Tree spatial distribution patterns of plantation and natural forest presented the same,which all showedreunion distribution in half-mature forest,partial reunion distribution in near-mature forest,and random distribution in mature forest.The frequency of dominance in the three age stages all was at moderate state.The growth space of plantation and natural forest in the three age stages all was under insufficient state.(2)The status of species diversity and natural regeneration of tree,shrub and herb in different age stages and different origins were compared and analyzed.According to the multiplicity index value between larix plantation and natural forest through principal component analytical method,the result showed that the species diversity of natural forest was better than that of plantation.Based on the comprehensive evaluation method of entropy method and negative correlation coefficient method,the evaluation index system of larix forest was developed.The natural update status of half-mature plantation was better than those of near-mature forest and mature forest,and near-mature natural forest was better than those of half-mature and mature forest.(3)According to the study of functional requirements of larix forest,the functional requirements of biodiversity protection,water conservation and carbon sink function were determined.The evaluation index system of larix forest in jingouling forest farm was establishmented through synthetic weight method,including a total of 9 structural factors which were the multiplicity index value,shrub coverage,conifer-broadleaf ratio,age stage,canopy density,herb coverage,gradient,stand biomass and stand volume..Based on the data of sample plot survey,the multifunctional evaluation of local larix forest was carried out,and the results were as follows:(a)The biodiversity protection curve and carbon sink function curve were increased with stand age from the beginning and then tended to be gentle at mature stage,while water conservation curve decreased with stand age from the beginning and then increased in half-mature stage till in mature stage when it came to be gentle.The multifunctional curve increased with stand age from the beginning and then tended to be gentle at the age of 46 of plantation,compared to the age of 110 of natural forest.(b)The relationship between biodiversity protection function and water conservation function with the age was opposite from the beginning and then turned into mutual beneficial;the relationship between biodiversity protection function and carbon sink function was mutual beneficial,and with the increase of carbon sink function,the biodiversity protection function increased;the relationship between water conservation function and carbon sink function was opposite from the beginning and then turned intomutual beneficial with the age increased.(c)There was a significant positive correlation between the biodiversity protection function,water conservation function and carbon sink function of larix forest,but there was no significant correlation between the biodiversity protection function and water conservation function.(4)The vision,target,target structure system and adjusting technology of multifunctional management on larxi forest were analyzed,to propose a multifunctional management model for larix forest of different age stages and origins,which with biodiversity protection function as the leading function,water conservation function and carbon sink function are taken into account.This model made the theoretical basis for the multifunctional management of larix forest. |
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