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Different Selective Cutting Intensity Stand Growth Simulation Of Natural Secondary Forest

Posted on:2013-01-18Degree:MasterType:Thesis
Country:ChinaCandidate:H R ChenFull Text:PDF
GTID:2213330374962848Subject:Forestry Engineering
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Abstract:The purpose of forest management is through the human control forest to play itsbiggest ecological,economic and social benefits.To achieve this goal,we must know the nature,space structure distribution and the growth change rule of the stand in order to predict the futuredevelopment tendency of the stand and reaction of the management measures.It is a biglimitation only rely on a simple mathematical model for forest management decision because thestructure of natural secondary is complicated and species are various. With the rapiddevelopment of computer technology,it is not only provide reliable information for the forestmanagement decision,make the forest management becomes simple and fast,but also have greatpractical value on the forest landscape planning and design and forestry simulation teachingthrough the visual dynamic simulation.The sample plots are the only well-preserved typical subtropical natural secondary forest forlong-term tracking set up in Dayuan forest logging and regeneration station in Jian'ou County,Fujian province in china.In1996it has already been completed at the end of the communitysurvey and investigation after different intensity selective cutting.In2006the natural recoveryafter10years review has completed.On the basis of these investigations,we carry outcommunity characteristic and forest ecological factor investigation after15years of naturalrecovery.Then these long-term reiteration data are used to construct the selective cuttingintensity as the main influencing factors of single wood growth equation of DBH,tree height andtree height curve equation;the tree height curve equation derive the single volume equationsuitable for production in the region combining with the construction of single wood models asthe basis to simulate the stand growth dynamic.Finally,Onyx TREE and3D MAX software areused to simulate each period of stand growth status in the different intensity selective cuttingstand combining with the PHOTOSHOP technology to product the stand growth changes'dynamic picture,to realize the dynamic simulation of stand growth and to provide the basis forthe subtropical natural secondary forest ecological cutting and updated technology research.The results of the study show that the Gomperts function is optimal for fitting diameter andheight growth models,which taking age as the independent variable.According to preliminary simulation in different intensity selective cutting stand,low intensity and medium intensity isbenefit to cultivate large diameter timber.The standard height curve is15.8%increased than theaverage tree height curve,which shows the standard height curve model has more extensiveapplicability than the average tree height curve model.Considering the advantages anddisadvantages of single entry volume equation and binary volume equation deduced the oneentry volume which have the medium precision.Therefore,when diameter and height data wereeasy to get,binary volume equation should be used,otherwise,the deduced one entry volumeequation should be chosen.Through constructing the negative-exponential function which has time sequence canpredict the stand diameter structure in30years.Then combing with measured data after10yearsand15years recovery,we discuss the future development trend in different intensity selectivecutting stand.In the future,Castanopsis carlesii and Castanopsis eyrei will become the leader inlow intensity stand,Castanopsis carlesii will lead the medium intensity stand,and both thesetwo stand space structure will gradually stability;Castanopsis eyrei will become the leader inhigh intensity stand,Castanopsis carlesii will lead the over-high intensity stand,and both thesetwo stand space structures will get worse.From the point view of the sustainable management ofnatural forest,the selective intensity should choose low intensity and medium intensity.Through the stand growth dynamic process simulation,we found that after a period of timerecovery of low intensity and medium intensity square,the stand general structure inline tostabilize,and medium intensity recovery speed faster than low intensity.After a period of timerecovery of the high intensity,over-high intensity and clear cutting square,the stand generalstructure starts to decline,especially before the maturing of clear cutting square.The non-cuttingsquare will also decline after a period of natural growth to mature.This conclusion furtherverified the superiority of low intensity and medium intensity selective cutting,and providescientific basis to the decision-making for department of forestry production when they choosereasonable forest management strategy....
Keywords/Search Tags:natural secondary forest, selective cutting intensity, growth dynamics, standstructure, simulation
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