Aims Growth-induced irreversible stem expansion(GROrate)and tree water deficit-induced stem shrinkage(TWD)reflect the responding characteristics of trees to environmental change,which are affected by different factors,so that their responses to environmental factors are different.Knowledge of radial growth dynamics and its response to environmental factors is crucial for understanding the tree growth and physiological characteristics to climate change.Methods Dendrometer was used to record the radial growth process of Castanopsis hystrix from 2018 to 2020,and climatic factors were measured simultaneously.The main goal of this study was to analyze GROrate and TWD dynamics and its relationship with environmental factors.Important findings The radial growth of C.hystrix began from March 4 to April 1,ended from September 23 to November 5,and the maximum growth rates occurred from May 31 to June 8.Within the growing period,growth was intermittent,and the actual growing days accounted for 47.8％-74.1％of the whole growing season.The longer the growing period,the more days with growth occurred.On the diurnal scale,the GROrate was positively related with relative humidity(RH),precipitation(P),photosynthetically active radiation(PAR)during the main growing period(April to September).However,the negative correlation was observed between TWD and above mentioned factors.The 21-day sliding correlation showed that vapor pressure deficit(VPD),P and RH were the key factors affecting radial growth of C.hystrix in most time of the growing season from 2018 to 2020.On the monthly scale,the GROrate was highly synchronized with the monthly rainfall events,while TWD was synchronized with the dry period.Taken together,these results showed that the radial changes of C.hystrix is primarily responsive to moisture-related environmental factors.This finding will help to better predict the growth response of forest dynamics under climate change.
关键词
径向变化动态/环境响应/树木水分亏缺/径向变化记录仪/红锥/亚热带
Key words
radial variation dynamics/environmental response/tree water deficit/dendrometer/Castanopsis hystrix/subtropics
维普
万方数据