摘要 【目的】以小兴安岭林区兴安落叶松人工林为研究对象,基于林分空间结构参数和经营密度表确定采伐强度及采伐木,对林分空间结构进行优化,分析优化效果,为人工林空间结构优化提供理论依据。【方法】在黑龙江省伊春市南岔县设置4块面积为0.2 hm2的兴安落叶松人工林固定样地,选择常用林分空间结构参数角尺度、大小比数、竞争指数和开阔比,并构建空间结构评价指数,结合兴安落叶松经营密度表确定采伐强度和采伐木,并分析间伐前后林分空分间结构变化。【结果】样地中的林木分别属于聚集分布、随机分布和均匀分布,中小径级林木较多,处于劣势状态,林木的生长空间处于严重不足状态和不足状态,林木竞争压力较大,各样地评价等级都为2级。根据经营密度表对监测样地2和监测样地4进行采伐,采伐株数强度分别为20.7%和12.7%,采伐之后角尺度分别降低3.9%和增加3.8%,大小比数分别降低0.5%和0.4%,竞争指数分别降低16.8%和5.2%,开阔比分别增加24.5%和4.2%,空间结构评价指数分别增加27.8%和7.2%。【结论】采用林分空间结构参数结合经营密度表进行林分抚育间伐可以有效改善林分空间结构,提升林木生长空间和优势程度,并减小了竞争压力。 [Objective]Taking the Larix gmelinii plantation in Xiaoxing’an Mountains of northeastern China as the research object,based on the spatial structure parameters and management density table of the stand,the cutting intensity and logging were determined,the spatial structure of stand was optimized,and the effects of optimization were analyzed to provide theoretical basis for the optimization of the spatial structure of the plantation.[Method]In Nancha County,Yichun City of Heilongjiang Province,four fixed sample plots of Larix gmelinii plantation with an area of 0.2 ha were set up.The angle scale,size ratio,competition index and opening ratio of the commonly used stand spatial structure parameters were selected,and the spatial structure evaluation index was constructed.The cutting intensity and cutting wood were determined by combining the management density table of Larix gmelinii,and the spatial structure changes before and after thinning were analyzed.[Result]The forest trees in the sample plot belong to the cluster distribution,random distribution and uniform distribution.There were many medium and small diameter trees,which were in a disadvantaged state.The growth space of the trees was in a serious and insufficient state,and the forest competition pressure was relatively high.The evaluation grades were all level 2.According to the management density table,the monitoring sample plot 2 and monitoring sample plot 4 were harvested.The harvesting plant number intensity was 20.7%and 12.7%,respectively.After harvesting,the angular scale decreased by 3.9%and increased by 3.8%,and the size ratio decreased by 0.5%and 0.4%,respectively.The competition index decreased by 16.8%and 5.2%,the openness ratio increased by 24.5%and 4.2%,and the spatial structure evaluation index increased by 27.8%and 7.2%,respectively.[Conclusion]Using stand spatial structure parameters combined with management density table for thinning can effectively improve stand spatial structure,improve the growth space and dominant degree of trees,and
出处 《北京林业大学学报》 CAS CSCD 北大核心 2021年第4期68-76,共9页 Journal of Beijing Forestry University
基金 “十三五”国家重点研发计划项目(2017YFD0601204)。
关键词 人工林 林分空间结构 抚育间伐 空间结构评价指数 plantation stand spatial structure tending and cutting spatial structure evaluation index
