| Quercus variabilis plantation is a typical type of forest vegetation in the mountainous area of Henan.It is also an excellent tree species for soil and water conservation,water conservation forests and shelter forests.It has a well-developed root system,strong adaptability,and can improve soil,but most of them are the same forest age and have a fragile structure.;Adopting the target tree operation method to adjust the spatial structure of top tree species and main associated tree species can create and maintain the best forest stand spatial structure,and promote cork oak plantations to form a healthy and stable forest ecosystem,thereby achieving natural regeneration.Make the cork oak plantation give full play to its due ecological functions,and achieve the sustainability of the cork oak plantation.This paper takes the representative Quercus variabilis plantation in the state-owned Dengfeng Forest Farm in Zhengzhou City as the research object.A large sample plot of 100m×100m is set up to locate and investigate each tree in the sample plot.The target tree operation method is adopted.,According to the accumulation intensity of 10%,20%,30%of the simulated harvesting respectively,that is,select different numbers of target trees and interference trees,and simulate the removal of the interference trees,and then analyze the target trees and special targets under different simulated harvesting intensities Non-spatial structure,spatial structure,tree point pattern and other structured management evaluation indicators of trees,dominant trees and whole stands,and use stand simulation tending cutting index to compare the optimization effect of stand structure under different simulation cutting intensities,and the simulation results The cutting intensity with the best forest stand simulation tending cutting effect provides a reference for the sustainable management of the variegated oak plantation in the state-owned Dengfeng Forest Farm.The main findings are as follows:1.By comparing the distribution characteristics of forest stand diameter structure and tree height structure under different simulated cutting intensities,it can be seen that after the target tree operation method is used for simulated cutting,the forest trees and trees with diameter steps between 10 and 14 cm are reduced.High-level forest trees between 10-12m.The KS test and AD test were used to test the goodness of fit of the stand diameter distribution and tree height distribution at the time of non-cutting and 10%,20%,and 30%of the accumulation intensity.For the 10%,20%,and 30%of the accumulation intensity,the Weibull distribution and the Lognormal distribution are the best for the diameter distribution during the simulated harvesting,and the Weibull distribution and the Normal distribution are the best for the tree height distribution.2.The results of the research on stand stability under different simulated cutting intensities show that after simulated cutting,the stability of forest stands has been improved.Among them,30%of the accumulation intensity has the best improvement effect;The stand stability values of 10%,20%,and 30%of the intensity of simulated felling were 0.8754,0.8726,0.8672,0.8652,respectively,which decreased with the increase of felling intensity.3.The research results of the stand spatial structure parameters under different simulated felling intensities show that the mixed degree after simulated felling shows that logging can increase the degree of isolation between tree species.Among them,the isolation between tree species is simulated at 30%of the accumulation intensity.The degree of mixing is the largest;the mixed degree of uncut and simulated logging at 10%,20%,and 30%of the accumulation intensity are 0.0311,0.0330,0.0352,0.0406,respectively,which increase with the increase of the logging intensity;the spatial distribution of the forest stand after simulated logging The pattern shows that logging can improve the spatial distribution pattern of forest stands.Among them,the forest stands at 30%of the accumulation intensity simulated harvesting are closest to random distribution;the uncut and the simulated harvesting at 10%,20%,and 30%of the accumulation intensity are the closest to the random distribution.The average angular scales were 0.3821,0.3815,0.3761,0.3694,and the average spatial density indexes were 0.7158,0.7041,0.6888,and 0.6748,all of which decreased with the increase in logging intensity.4.The research results of the vertical structure under different simulated harvesting intensities show that the forest layer index after simulated harvesting shows that logging can improve the vertical structure relationship of the forest stand.Among them,the vertical structure is the best when simulated harvesting at 30%of the accumulation intensity;The average forest index for logging and simulated logging at 10%,20%,and 30%of the accumulation intensity were 0.5906,0.5925,0.6020,and 0.6084,respectively,which increased with the increase of the logging intensity.The openness after simulated felling shows that logging can increase the openness of forest separation.Among them,the openness is the largest when the simulated harvesting is 30%of the accumulation intensity;when the uncut and the simulated harvesting is 10%,20%,and 30%of the accumulation intensity The average openness of the plant was 0.3080,0.3302,0.3681,0.4004,respectively,which increased with the increase of the cutting intensity.The average competition index of the target tree after simulated felling shows that logging can reduce the competitive pressure of the target tree.Among them,the competitive pressure of the target tree is the smallest when the target tree is simulated at 30%of the accumulation intensity,and the uncut and 10%,20%of the accumulation intensity The average competition index of target trees during 30%simulated logging were 2.1431,1.7121,1.4941,1.3881(P<0.05),which decreased with the increase of logging intensity.5.The binary distribution characteristics of forest stand spatial structure parameters show that the proportion of the same species of reference tree and its neighboring trees with the same degree of differentiation decreases with the increase of simulated logging intensity.%,30%when simulated harvesting is 90.90%,90.45%,89.97%,88.89%;the proportion of evenly distributed and associated with another tree species increases with the increase of simulated harvesting intensity,and the proportion of un-cutting and accumulation intensity is 10%.The percentages of%,20%,and 30%in simulated logging were 22.43%,22.49%,24.46%,and 25.79%respectively;the proportion of trees with the same degree of differentiation in uniform and random distribution remained basically unchanged.6.Research on the distribution pattern of tree points under different simulated logging intensities shows that the tree point distribution pattern after simulated logging shows that the tree point distribution pattern can be achieved by logging.The point distribution pattern of the whole forest trees on the sample plot when not harvested was firstly clustered(0-33 m),then randomly distributed(33-38m),and finally showed a weak clustering distribution(greater than 38m);simulated by 10%of accumulation intensity When harvesting,it is randomly distributed in the spatial scale of 0～1m,31～43m,47～49m,and the degree of aggregation is within the spatial scale of 1～31m,43～47m,49～50m;simulation is based on 20%of accumulation intensity When harvesting,it is randomly distributed in the spatial scales of 0-2m,27-44m,and 49-50m,and clustered in the spatial scales of 2-27m and 44-49m;when logging is simulated at 30%of the accumulation intensity,It is randomly distributed in the space scale of 0～2m;the overall distribution tends to be randomly distributed in the space scale of 2～50m.7.The study on the forest stand simulated tending cutting index under different simulated cutting intensities shows that cutting can improve the spatial structure of the forest stand.The uncut and 10%,20%,and 30%of the accumulation intensity of the forest stands at the time of simulated cutting.The simulated tending harvesting index value(T)is 0.1213,0.1250,0.1360 when the simulated harvesting is 10%,20%,and 30%of the accumulation intensity,respectively;when the simulated harvesting intensity is 30%,the T value is the largest,that is,the harvesting intensity is 30%At the time,the forest stand structure optimization effect is the best. |
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