林业科学2025，Vol.61Issue(9)：39-47,9.DOI:10.11707/j.1001-7488.LYKX20230537
蒙古栎次生林林下红松幼树开敞度优化方法
Optimization Method of Canopy Openness Index for Korean Pine Saplings within a Mongolian Oak Secondary Forest
摘要
Abstract
[Objective]The purpose of this study was to improve the light conditions of the Korean pine saplings under the forest by simulating the cutting of the canopy layer of the secondary forest,so as to promote the growth and development of the Korean pine saplings and accelerate the recovery process of the secondary forest.[Method]According to distance control and growth quality,Korean pine saplings were selected from the core area in a 1 hm2 large plot of Mongolian oak secondary forest.Individual openness optimization schemes with different thresholds(KT=1,1.5,2)were used to control the openness of target Korean pine saplings under the forest.The openness optimization scheme is implemented through a two-level iterative optimization method,encompassing both tree and stand levels.At the tree level,the objective is to ensure that the openness of each target Korean pine sapling meets the predefined threshold value.Simultaneously,at the stand level,the optimization involves controlling a specific target Korean pine sapling while taking into account other target Korean pine saplings within the stand.The changes of non-spatial structure(total diameter classes,total species and canopy density)and spatial structure(uniform angle index,neighbourhood comparison and mingling)of stands before and after simulated cutting under different openness thresholds were compared,as well as the differences in openness and openness change rate of Korean pine saplings under different treatments.[Result]A total of 145 target Korean pine saplings were selected by distance control and growth quality.The target Korean pine saplings were 1.1-4.9 m in DBH,1.5-4.7 m in height and 0.6-1.7 m in crown radius.When KT was 1,1.5 and 2,the target Korean pine saplings reach the openness condition after cutting 14,130 and 262 canopy trees for 3,6 and 8 rounds respectively.After the optimized cutting simulation,the openness of Korean pine saplings was improved as a whole:when KT was 1,the openness increased by 5.7%on average compared with the control,but there was no significant difference;when KT was 1.5,the openness was 44.7%on average higher than that of the control,with significant difference;when KT was 2,the openness was 107.7%on average higher than that of the control,with significant difference.Pre-and post-simulated harvesting activities exhibited no alterations in the total diameter classes and total species within the forest stand.Moreover,spatial structural metrics exhibited minimal changes.Under three different thresholds of openness(KT=1,1.5,2),the stocking intensity of harvesting is 1.5%,15.6%,and 37.2%respectively.Compared with the canopy density of the control(CK)at 0.646,the canopy density under the three openness thresholds(KT=1,1.5,2)decrease by 0.5%,13.3%,and 33.1%respectively.[Conclusion]The two-level iterative optimization method for the openness index of Korean pine saplings improved the light conditions of Korean pine saplings under the forest,while maintaining the stability of most stand structures,and the openness threshold KT=1.5 was better than KT=1 or 2.The optimization methodology introduced in this research enables the determination of key parameters,including the total count of cutting rounds,the number of cutting trees within each round,the openness regulation route of each target Korean pine sapling and the distribution of cutting trees under different openness thresholds.This comprehensive framework offers invaluable guidance for shaping the post-replanting thinning strategy of Korean pine saplings and informs best practices for managing secondary forest ecosystems.关键词
冠层优化/开敞度调控/蒙古栎次生林/红松幼树Key words
canopy optimization/openness/Mongolian oak secondary forest/Korean pine saplings分类
农业科技引用本文复制引用
刘迪,周超凡,雷相东,刘宪钊,张会儒,何潇..蒙古栎次生林林下红松幼树开敞度优化方法[J].林业科学,2025,61(9):39-47,9.基金项目
"十四五"国家重点研发计划"森林立地质量评价与全周期多功能经营关键技术"(2022YFD22005) （2022YFD22005）
国家自然科学基金项目面上项目"基于博弈论的近自然防护林单木稳定性机制"(32271878). （32271878）
