窗口宽度对树木径向生长与气候要素之间关系的影响

Effect of Window Width on Relationship between Tree Radial Growth and Climatic Elements

在神农架林区的太子垭地区,以神农架建群树种巴山冷杉(Abies fargesii)为研究对象,利用生长锥在样木胸高处(1.3 m)进行树芯取样(24棵树50个样芯),应用LINTAB TM轮宽测量仪测量样本生长轮宽度,应用COFFCHA程序进行定年及测量质量控制,应用ARSTAN程序进行生长趋势拟合并合成标准年表(1880—2021年);依据年表及日平均气温、日降水量数据(1953—2021年),应用R程序中树轮工具包,将滑动窗口宽度下限设置为21 d、上限设置为270 d,分析树木生长轮与不同窗口宽度气候要素的相关性。结果表明:神农架地区巴山冷杉径向生长的最佳气温窗口期为33 d、最佳降水量窗口期为28 d。与传统月度气候数据相比,树木生长轮与气候最佳窗口期的相关性更显著。当年3月份、9月份中旬平均气温显著促进巴山冷杉径向生长;而当年9月份和上年9月份的降水量、当年和上年5月份的平均气温,显著抑制巴山冷杉的径向生长。

To understand the influence of window width on the relationship between tree radial growth and climatic factors, we took the Shennongjia- established tree species Abies fargesii as a research object. Samples (50 cores from 24 trees) were cored at breast height (1.3 m) using increment core, and the width of growth rings was measured using the LINTABTM, then the quality for dating and measuring was insured by using the COFFCHA program. After that, the growth trend was detrended, and then standard chronology (1880-2021) was produced using the ARSTAN program. With the chronology and mean daily temperature and precipitation data (1953-2021), the DendroTools package implied in the R program was applied, by setting the lower sliding window width to 21 d and the upper to 270 d, and analyzing the correlation between chronology and climate elements with different window widths. The optimal window for radial growth of A. fargesii in the research area was 33 d for temperature and 28 d for precipitation, and the correlation between the tree growth ring and the optimal climate window was more significant than that of the traditional monthly climate data. The average temperature in March and mid-September of the current year significantly promoted the radial growth of A. fargesii , while the precipitation in September of the current year and the previous year, and the average temperature in May of the current year and the previous year significantly inhibited the radial growth of A. fargesii .