摘要
以大兴安岭兴安落叶松(Larix gmelinii)幼、中龄林为研究对象,以混交度、角尺度、大小比、林层比、开敞度5个空间结构参数为经营目标,以非空间结构为约束条件,采用乘除法构建大兴安岭天然落叶松林空间结构抚育优化模型;规划模型求解以蒙特卡罗随机抽样原则为基础,采用R语言编制森林经营模拟采伐程序,并对4个模拟采伐株数强度(10%、20%、30%、40%)进行5 000次随机模拟,筛选出各样地最适采伐强度及抚育方案。结果表明:(1)现有林分,径级结构分布相对合理;林分混交程度偏低,且林分水平分布格局整体呈随机分布;垂直结构分层多样性较差;林分内开敞度有待提高;单木生长营养空间有待优化。(2)以空间结构为主要调整目标,最适采伐株数强度40%时林分综合优化目标函数值最高,比采伐前分别提高59.01%(L_(01),100 m×100 m)、65.42%(L_(02),50 m×50 m)、108.47%(L_(03),50 m×50 m)。(3)在最优采伐强度时,筛选的最优采伐方案能够得到目标函数最大值,此时林分保持随机分布状态、混交度增大、垂直分层更加明显、开敞度提高、径级结构更加合理。
The natural young and middle-aged Larix gmelinii forests of Daxing’an Mountains were taken as the research object,and the five spatial structural parameters of mingling degree,uniform angle index,competition index,stand level rate and opening degree were taken as the management objectives,and the non-spatial structure was used as the constraint,we constructed tending optimization model of spatial structure of L.gmelinii forest using multiplication division method.We used the R language to compile the forest management simulation harvesting program on the principle of Monte Carlo random sampling,and set four simulation intensities:10%,20%,30%and 40%for 5 000 random simulations,and obtained optimum harvesting intensity and tending plan.The results show that:(1)Existing forests:the distribution of the diameter structure is relatively reasonable;the mingling degree of forest branching is low and the distribution pattern of forest stands is randomly distributed;the hierarchical structure of vertical structure is simple;the openness of forest separation needs to be improved;individual tree nutrition space needs to be optimized.(2)When the spatial structure is the main adjustment target,the optimal harvesting number is 40%.The comprehensive optimization objective function of the stand is the highest,which is increased by 59.01%(L01,100 m×100 m),65.42%(L02,50 m×50 m)and 108.47%(L03,50 m×50 m)before harvesting,respectively.(3)At the optimal harvesting intensity,the optimal harvesting scheme can obtain the maximum value of the objective function.At this time,the stand is kept in a random distribution state,the mingling degree increases,the vertical stratification is more obvious,the opening degree is improved,and the diameter structure is more reasonable.
作者
姜廷山
王鹤智
董灵波
陈莹
刘兆刚
Jiang Tingshan;Wang Hezhi;Dong Lingbo;Chen Ying;Liu Zhaogang(Northeast Forestry University, Harbin 150040, P. R. China;Survey & Planning Institute of State Forestry Administration)
出处
《东北林业大学学报》
CAS
CSCD
北大核心
2018年第12期9-14,19,共7页
Journal of Northeast Forestry University
基金
国家重点研发计划项目(2017YFC0504103)
国家自然科学基金项目(31700562)
关键词
兴安落叶松林
空间结构优化
采伐强度
蒙特卡罗模拟
大兴安岭
Larix gmelinii forest
Spatial structure optimization
Cutting intensity
Monte Carlo simulation
Daxing’an Mountains
