林分密度对兴安落叶松径向生长-气候关系的影响  

Effect of stand density on radial growth-climate relationship of Larix gmelinii

作　　者：韩新宇 高露双[1] 秦莉[2] 庞荣荣 刘鸣谦 朱一泓 田益雨 张金 HAN Xinyu;GAO Lushuang;QIN Li;PANG Rongrong;LIU Mingqian;ZHU Yihong;TIAN Yiyu;ZHANG Jin(College of Forestry,Beijing Forestry University,Beijing 100083,China;Institute of Desert Meteorology,China Meteorological Administration,Urimqi 830002,China;University of California,Berkeley,Berkeley California 94704,USA;Wuerqi Khan Forest Industry Co.,Ltd.,Hulun Buir 022159,China)

机构地区：[1]北京林业大学林学院,北京100083 [2]中国气象局乌鲁木齐沙漠气象研究所,新疆乌鲁木齐830002 [3]University of California,Berkeley,Berkeley California 94704 [4]乌尔旗汉森林工业有限公司,内蒙古呼伦贝尔022159

出　　处：《南京林业大学学报（自然科学版）》2024年第2期182-190,共9页Journal of Nanjing Forestry University：Natural Sciences Edition

基　　金：国家重点研发计划(2022YFD2201001-04)。

摘　　要：【目的】研究不同密度下兴安落叶松径向生长与气候因子动态关系,为全球变暖背景下兴安落叶松林可持续经营中合理的林分密度确定提供依据。【方法】根据林分密度指数(SDI)选取大兴安岭中北部地区低、中和高3种林分密度梯度兴安落叶松(Larix gmelinii)纯林为研究对象,采用Mann-Kendall检验确定研究区气温突变点,基于野外调查和树轮数据,分析气温突变点后各林分密度下兴安落叶松径向生长趋势,并利用皮尔森相关和滑动相关分析其与各气候因子的关系及稳定性。【结果】在气温突变点后,研究区域兴安落叶松生长出现增强和衰退趋势,且随着林分密度增加,树木生长衰退比例增高。高林分密度下兴安落叶松生长受抑制程度最高,1988—1990年平均生长变化率为-25%,处于衰退状态。林分密度改变了兴安落叶松生长对气候的响应关系,高密度下衰退组树木生长与8月标准化降水蒸散指数(SPEI)正相关关系最强(P<0.05),与夏季温度呈稳定的显著负相关关系(P<0.05)。研究区气候呈现明显暖干化趋势,而低林分密度兴安落叶松保持54%的生长增强比例,树木与温度由低密度下的正相关关系向高密度的负相关关系转变。【结论】气温发生显著改变后,随着林分密度增加,树木生长衰退比例增高。低密度林分对干旱的抵抗力较强,而高密度林分增强了树木生长对气候因子的敏感性。因此,较低林分密度可以减缓气候变暖对兴安落叶松生长带来的负面影响,调整林分密度成为减缓兴安落叶松林树木生长衰退趋势的必要经营措施。【Objective】To develop a sustainable management plan for Larix gmelinii,which is influenced by climate change,it is crucial to understand the dynamic relationship between radial growth and climate in forests with different tree densities.【Method】Based on the stand density index,nine plots with three density levels(low,middle,high)were established in the central and northern Greater Khingan Mountains.Tree cores of L.gmelinii were collected during a field investigation.The Mann-Kendall test method was used to determine the turning point of temperature in the study area.To examine the radial growth trend of L.gmelinii,negative exponential function detrending and a linear function fitting were applied.Then,a Pearson correlation and sliding correlation were used to analyze whether the relationship between the radial growth and climate factors under each stand density remained stable after the temperature turning point.【Result】The radial growth of L.gmelinii displayed trends of both enhancement and decline after the temperature turning point.The proportion of declining trees increased with increasing stand density.The growth of L.gmelinii was strongly inhibited when the stand density was high.Its average growth change rate reached-25%during 1988-1990,indicating a serious growth decline.Instead,the L.gmelinii trees in low density plots maintained a 54%growth enhancement ratio.Stand density may also influence the response of L.gmelinii growth to climate.Under a high stand density,the L.gmelinii growth of the decline group was positively correlated with the standardized precipitation evapotranspiration index in August(P<0.05)and negatively correlated with summer temperature(P<0.05),but under a low stand density,the growth of L.gmelinii was positively correlated with temperature.With the warming and drying trend in the study area,the relationship between tree growth and temperature shifted from positive to negative with increasing stand density.【Conclusion】The proportion of declining trees increased with inc

关 键 词：兴安落叶松 林分密度 径向生长 气候因子 

分 类 号：S791[农业科学—林木遗传育种]