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基于
竞争
截止
系数
崇礼
人工林
目标
抚育
模拟
张晓红
doi:10.11707/j.1001-7488.LYKX20210869基于光竞争截止系数的崇礼冬奥核心区华北落叶松人工林目标树抚育间伐模拟*张晓红1,2周超凡1,2张状1,2冯林艳1,2符利勇1,2张会儒2,3(1.中国林业科学研究院资源信息研究所北京 100091;2.国家林业和草原局森林经营与生长模拟实验室北京 100091;3.中国林业科学研究院华北林业实验中心北京 102300)ccc摘要:【目的】以崇礼冬奥核心区华北落叶松人工近熟林为研究对象,探讨目标树抚育间伐采伐木选择方法及其对林分空间结构的影响,为更加合理开展森林经营活动、促进人工林质量提升提供科学依据。【方法】设置并调查 6块面积 0.09 hm2(30 m30 m)标准地,按 125 株hm2目标树密度,采用定性与定量指标相结合的方法标记目标树。基于树冠重叠和树冠光竞争高度构建采伐木选择指标,设置不同光竞争截止系数(c)模拟选择采伐木,分析采伐强度变化,运用角尺度、混交度、密集度、交角竞争指数、林层指数和综合空间结构指数分析不同 c 值下目标树和林分空间结构指标的变化。【结果】c 取值在 01 之间时,株数采伐强度和断面积采伐强度在 10%35%范围内变化,且呈随 c 值增大而降低的相同变化趋势。经模拟采伐后目标树空间结构得到优化,改善幅度随采伐强度增大而增大。综合空间结构指数在 值 0.6 时达到最大提升幅度 45.50%,角尺度和密集度在 值 0.7 时变化幅度最大,分别为 17.93%和 46.83%,其他空间结构参数在 值 0.6 时达到最大变化幅度。抚育间伐可同时优化林分空间结构,对林分树种隔离程度、林木透光条件和竞争水平均具有不同程度改善。【结论】基于树冠重叠和树冠光竞争高度的采伐木选择方法,可通过调整光竞争截止系数控制采伐强度。树冠光竞争截止系数可作为目标树经营采伐木选择的约束条件,但具体抚育对象和抚育方式须结合林分特征和作业要求而定。关键词:目标树经营;采伐木;光竞争截止系数;冬奥核心区;空间结构;抚育中图分类号:S750文献标识码:A文章编号:10017488(2023)02003010Simulation on Crop Tree Management Tending and Thinning of Larix principis-rupprechtiiPlantation in Chongli Winter Olympics Core Area Based on Coefficient of Light CompetitionZhang Xiaohong1,2Zhou Chaofan1,2Zhang Zhuang1,2Feng Linyan1,2Fu Liyong1,2Zhang Huiru2,3(1.Research Institute of Forest Resource Information Techniques,CAFBeijing 100091;2.Key Laboratory of Forest Management and Growth Modeling,National Forestry and Grassland AdministrationBeijing 100091;3.Experimental Centre of Forestry in North China,CAFBeijing 102300)cccccAbstract:【Objective】Taking larch near-mature plantations(Larix principis-rupprechtii)in the core area of Chongli WinterOlympics as objects,this paper was carried out to discuss the selection method of target trees thinning and its effects on forestspatial structure in order to provide scientific bases for reasonable management activities making and plantation qualityimprovement.【Method】Six sample plots with the area of 0.09 hm2(30 m 30 m)were set up and measured.125 tree hm2target trees were marked according to qualitative and quantitative indicators.Based on crown overlap and crown light competitionheight,the method of cutting trees selection was developed,which was used to select cutting trees simulated in 6 sample plots bysetting different values of light competition coefficient().Changes on cutting intensity were analyzed while those of target treeand stand spatial structure indexes under different c values were analyzed by using angular scale,mingling,crowding,intersectioncompetition index,storey index and comprehensive index.【Result】The cutting intensity of both tree number and basal areavaried from 10%to 35%when the value of ranged from 0 to 1,indicating the same trend of decreasing with the increase of valueof.The spatial structure of target trees was optimized by simulated tending thinning,and the improvement increased along withthe increase of cutting intensity.The maximum increase of comprehensive spatial structure index was 45.50%when value of was0.6.The maximum improvement of angular scale and crowding were 17.93%and 46.83%,respectively,under value was 0.7,收稿日期:20211124;修回日期:20220119。基金项目:张家口市崇礼区森林防火综合体系建设无人机巡护监测系统(DA2020001);基于无人机平台的荒漠植被信息提取和生物量动态计测(CAFYBB2019QD003);国家自然科学基金面上项目(31971653)。*张会儒为通讯作者。第 59 卷 第 2 期林业科学 Vol.59,No.22 0 2 3 年 2 月SCIENTIA SILVAE SINICAEFeb.,2 0 2 3cwhile other spatial structure parameters reached the maximum improvement with the values of is 0.6.Thinning also optimized thespatial structure of stand,and improved the isolation degree of tree species,light transmission conditions and competition levelamong trees in different degrees.【Conclusion】The thinning intensity could be controlled by adjusting the coefficient of lightcompetition using cutting trees selection method based on crown overlap and crown light competition height.The coefficient ofcanopy light competition could be used as a constraint for selecting cutting trees of crop tree management.However,the thinningobjects and thinning methods should be determined according to the stand characteristics and operation requirements.Key words:crop tree management;cutting trees;coefficient of light competition;Winter Olympics core area;spatial structure;tending 目标树经营是一种通过降低邻木冠层竞争、增加目标树生长空间提高单株木质量的营林技术,可以看作一种特殊的抚育间伐,是实现近自然森林经营的重要途径(Pommerening et al.,2019),选择目标树、伐除干扰木是增加目标树生长空间的重要手段,也是目标树经营的核心。不同于下层间伐、上层间伐和机械间伐等常规抚育间伐,目标树经营的间伐对象是影响目标树生长的竞争木、干扰木,不涉及目标树树冠以下的邻木(Healy et al.,1999)。因此,开展目标树抚育间伐研究对合理制定人工林近自然经营措施具有重要意义。当前,有关目标树抚育间伐研究主要集中在间伐对单木和林分的生长影响方面,结果发现目标树抚育间伐能够显著提高单株目标树的胸径定期生长量和材积定期生长量(Kochenderfer et al.,2001;宁金魁等,2009;何友均等,2013;王懿祥等,2014;李婷婷等,2015;周超凡等,2022),促进林分断面积和蓄积增长,如经过目标树抚育间伐的美国北方黑桦(Betula lenta)8 年间胸径定期生长量和材积定期生长量约为对照目标树的 2 倍(Schuler,2006),长 白 山 蒙 古 栎(Quercusmongolica)次生林 3 年间林分断面积和蓄积定期生长率约为对照样地的 2.5 和 3.6 倍(张晓红等,2020)。也有学者探讨目标树抚育间伐对林分结构的影响,结果发现目标树抚育间伐能够在短期内改变林分密度和物种组成(Zenner et al.,2008),调整垂直结构,降低林木竞争水平(张晓红等,2019;胡雪凡等,2021),提高林木种间隔离程度,使林分空间分布格局趋于随机分布(胡雪凡等,2019),在实现目标树空间结构优化的同时,保证林分空间结构稳定(陈科屹等,2017)。以往研究主要对目标树的经营效果进行分析,较少关注间伐对象,事实上,抚育间伐对林分生长的促进作用和对结构的改善程度与间伐对象(即采伐木)选择密切相关(Li et al.,2014;王懿祥等,2014;张晓红等,2