Simulation Of Broad Leaved Mixed Forest For Intermediate Cutting Based On Optimized Stand Structure In Maoershan

Natural secondary forest is a kind of forest stands that restored through natural regeneration or artificially induced natural regeneration from a wildwood of which remarkable changes happen to the structure,species composition or basic function because of human destructive interference or abnormal natural disturbance.As the main body of terrestrial ecosystem,the structure of natural secondary forest wasn't stable,stand density was unreasonable,the shape and the quality was in poor state with a long time extensive operation.However,we should take scientific and reasonable management measures to establish a stable,reasonable forest community,which was meaningful to improve the productivity of Natural secondary forest community.Based on the data of 25 natural secondary broad leaved mixed forest permanent sample plots collected from 2015 to 2016 in Maoershan forest farm,we built the cutting index Fi used eight structural indexs,including mingling(Mi),neighborhood comparison(Ui),uniform angle index(Wi),compectitive index(CIi),spatial density(Di),health index(Hi),open degrees(Bi),aim index(Ai).Selective cutting operation was adopted with different intensities of cutting(no cutting,10%,20%and 30%)to obtain the optimum cutting intensity of each stand and make a suitable project of thinning.Using the bivariate distribution of structural parameter and stand structure index values to evaluate and verify the rationality of the tending scheme.The main results were as follows:(1)It was scientific and reasonable to determine that whether a tree should be cut or not by taking into account of Mi,Ui,Di and so on;(2)The degree of importance of the eight indexes for a hard broad leaf mixed forest was CIi?|Wi-0.5|?Bi?Ui?Hi?Ai?Mi?Di;(3)Compared the change of stand non-spatial and spatial structure under a given intensity,the cutting intensity of between 20%and 30%,with the stand volume cutting intensity under 15%could enhance the stability of forest community spatial structure effectively and its communities spatial structure was superior,and it can primely meet our expected demands for cutting.(4)Compared the change of the value of stand structure indexs and the bivariate distribution of spatial structural parameters to evaluate and verify the rationality of the thinning project,the results of analysis showed that the thinning project was reasonable,which could improve the stand structure and provide theoretical scientific basis for thinning in natural secondary broad leaved mixed forest in Maoershan.