摘要
研究不同海拔高度天然次生林径向生长特征及其对气候变化的响应,揭示影响山地树木径向生长的主要因子,对于研究气候变化对温带森林生态系统适应性生长、演替和可持续经营的影响具有重要意义。该研究以冀西北山地次生林优势树种白桦(Betula platyphylla)为对象,于研究区海拔1350、1550、1750、1950 m处分别设置样地,采集样木树芯和圆盘,运用树木年轮气候学方法建立白桦天然次生林标准年表,并将年轮宽度指数与气候因子进行相关、多元逐步回归分析。主要结果:(1)1960-2018年研究区气候呈变暖变干趋势,其中1960-1989年为平稳期,1989-2018年为快速期。(2)白桦次生林径向生长在1989年发生改变,年轮宽度指数呈现“增长-下降”的“Λ”形生长趋势。(3)在气候变化平稳期,白桦次生林径向生长在低海拔样地(B1350、B1550)与气温(平均气温、最高气温、最低气温)呈正相关关系,在高海拔样地(B1750、B1950)与上年和当年生长季降水量呈显著正相关关系;在气候变化快速期,低海拔样地(B1350、B1550)白桦次生林径向生长与生长季气温、生长季潜在蒸散发(ET_(0))呈负相关关系,高海拔样地(B1750、B1950)白桦次生林径向生长与生长季及生长季末期ET_(0)呈负相关关系。(4)在气候变化平稳期,温度对B1350、B1550、B1750样地白桦次生林径向生长的贡献率分别为76%、54%、51%,水分的贡献率为24%、46%、49%;在气候变化快速期,温度对B1350、B1550、B1750样地树木径向生长的贡献率分别为58%、41%、38%,水分的贡献率为42%、59%、62%;高海拔B1950样地树木生长始终受水分因子的控制。
Aims This study aims to determine the radial growth characteristics of natural secondary forests along an elevation gradient and their responses to climate change,and to identify the main factors affecting the radial growth of trees on mountain sites.The outcome of the study would be of great significance for understanding the impact of climate change on growth adaptation,succession and sustainable management in temperate forest ecosystems.Methods Field plots were set up at 1350,1550,1750,and 1950 m above sea level in the study area to collect samples of wood cores and discs.Tree-ring climatology method was adopted to establish the standard chronology of Betula platyphylla in natural secondary forest,and the annual ring width index and climate factors were subjected to correlation analysis and multiple stepwise regression analysis.Important findings From 1960 to 2018,climate in the study area showed a warming and drying trend,with 1960-1989 as a stable period and 1989-2018 as a period with rapid changes.A change occurred in the radial growth of B.platyphylla in 1989,with the annual ring width index displaying an“up-down”growth trend.During the stable period of climate change,the radial growth of B.platyphylla at the low-elevation sites(B1350,B1550)was positively correlated with temperature variables(i.e.average air temperature,maximum air temperature,minimum air temperature);whereas at the high-elevation sites(B1750,B1950),the growth was significantly and positively correlated with the precipitation of the previous year and during the growing season of current year.During the period of rapid climate change,the radial growth was negatively correlated with temperature and potential evapotranspiration(ET_(0))during the growing season at the low-elevation sites(B1350,B1550),and negatively with ET_(0) during the growing season and end of the growing season at the high-elevation sites(B1750,B1950).During the stable period of climate change,temperature explained 76%,54%,and 51%of the variations in radial growth,and
作者
李肖
PIALUANG Bounthong
康文辉
冀晓东
张海江
薛治国
张志强
LI Xiao;PIALUANG Bounthong;KANG Wen-Hui;JI Xiao-Dong;ZHANG Hai-Jiang;XUE Zhi-Guo;ZHANG Zhi-Qiang(School of Soil and Water Conservation,Beijing Forestry University,Jixian National Forest Ecosystem Observation and Research Station,CNERN,Beijing 100083,China;Forestry and Grassland Bureau of Chongli District,Zhangjiakou,Hebei 076350,China)
出处
《植物生态学报》
CAS
CSCD
北大核心
2022年第8期919-931,共13页
Chinese Journal of Plant Ecology
基金
国家水体污染控制与治理科技重大专项(2017ZX07101002-002)。
关键词
气候变化
径向生长
海拔
天然次生林
山地
冀西北
climate change
radial growth
altitude
natural secondary forest
mountains
northwest Hebei
