To study the effect of thinning intensity on the carbon sequestration by natural mixed coniferous and broad-leaf forests in Xiaoxing’an Mountains,China,we established six 100 m×100 m experimental plots in Dongfa...To study the effect of thinning intensity on the carbon sequestration by natural mixed coniferous and broad-leaf forests in Xiaoxing’an Mountains,China,we established six 100 m×100 m experimental plots in Dongfanghong For-est that varied in thinning intensity:plot A(10%),B(15%),C(20%),D(25%),E(30%),F(35%),and the control sample area(0%).A principal component analysis was performed using 50 different variables,including species diversity,soil fertility,litter characteristics,canopy structure param-eters,and seedling regeneration parameters.The effects of thinning intensity on carbon sequestration were strongest in plot E(0.75),followed by D(0.63),F(0.50),C(0.48),B(0.22),A(0.11),and the control(0.06).The composite score of plot E was the highest,indicating that the carbon sequestration effect was strongest at a thinning intensity of 30%.These findings provide useful insights that could aid the management of natural mixed coniferous and broadleaf forests in Xiaoxing’an Mountains,China.This information has implications for future studies of these forests,and the methods used could aid future ecological assessments of the natural forests in Xiaoxing’an Mountains,China.展开更多
Solar-induced chlorophyll fluorescence(SiF)is a promising new proxy for global carbon cycle monitoring.Although many studies consider SIF to be linearly correlated with gross primary production(GPP),the relationship b...Solar-induced chlorophyll fluorescence(SiF)is a promising new proxy for global carbon cycle monitoring.Although many studies consider SIF to be linearly correlated with gross primary production(GPP),the relationship between SIF and GPP is jointly influenced by instantaneous radiation,canopy structure,and plant physiological factors,and their complex interactions lead to intricate SIF-GPP dynamics.Current research on SIF and GPP in subtropical evergreen mixed forests remains limited,primarily due to the lack of observational data from forest flux sites.Based on observations from the Dabie Mountain subtropical evergreen forest flux station from 2023 to 2024,we investigated the relative contributions of the radiative,structural,and physiological components of SiF to the SIF-GPP relationship at different temporal scales.The results revealed that:(1)At both seasonal and diurnal scales,SIF effectively tracks the changes in GPP;(2)The radiative component of SIF dominates the SIF-GPP linear relationship,with canopy structural variations driving its seasonal-scale dynamics while physiological response mechanisms reduce the correlation at hourly scales;and(3)During the growing season,as the time scale increased from half-hourly to daily,the SIF-GPP correlation strengthened(R2 rising from 0.36 to 0.44),while the radiative component contribution decreased slightly and the physiological component contribution weakened.Understanding the influences of these different factors on the SIF-GPP relationship can contribute to the development of more accurate models for GPP estimation using SIF.展开更多
基金funded by National Key Research and development project(2022YFD2201001)Project for Applied TechnologyResearch and Development in Heilongjiang Province(GA19C006).
文摘To study the effect of thinning intensity on the carbon sequestration by natural mixed coniferous and broad-leaf forests in Xiaoxing’an Mountains,China,we established six 100 m×100 m experimental plots in Dongfanghong For-est that varied in thinning intensity:plot A(10%),B(15%),C(20%),D(25%),E(30%),F(35%),and the control sample area(0%).A principal component analysis was performed using 50 different variables,including species diversity,soil fertility,litter characteristics,canopy structure param-eters,and seedling regeneration parameters.The effects of thinning intensity on carbon sequestration were strongest in plot E(0.75),followed by D(0.63),F(0.50),C(0.48),B(0.22),A(0.11),and the control(0.06).The composite score of plot E was the highest,indicating that the carbon sequestration effect was strongest at a thinning intensity of 30%.These findings provide useful insights that could aid the management of natural mixed coniferous and broadleaf forests in Xiaoxing’an Mountains,China.This information has implications for future studies of these forests,and the methods used could aid future ecological assessments of the natural forests in Xiaoxing’an Mountains,China.
基金The National Natural Science Foundation of China(42250205)The‘CUG Scholar’Scientific Research Funds at China University of Geosciences(2019004)。
文摘Solar-induced chlorophyll fluorescence(SiF)is a promising new proxy for global carbon cycle monitoring.Although many studies consider SIF to be linearly correlated with gross primary production(GPP),the relationship between SIF and GPP is jointly influenced by instantaneous radiation,canopy structure,and plant physiological factors,and their complex interactions lead to intricate SIF-GPP dynamics.Current research on SIF and GPP in subtropical evergreen mixed forests remains limited,primarily due to the lack of observational data from forest flux sites.Based on observations from the Dabie Mountain subtropical evergreen forest flux station from 2023 to 2024,we investigated the relative contributions of the radiative,structural,and physiological components of SiF to the SIF-GPP relationship at different temporal scales.The results revealed that:(1)At both seasonal and diurnal scales,SIF effectively tracks the changes in GPP;(2)The radiative component of SIF dominates the SIF-GPP linear relationship,with canopy structural variations driving its seasonal-scale dynamics while physiological response mechanisms reduce the correlation at hourly scales;and(3)During the growing season,as the time scale increased from half-hourly to daily,the SIF-GPP correlation strengthened(R2 rising from 0.36 to 0.44),while the radiative component contribution decreased slightly and the physiological component contribution weakened.Understanding the influences of these different factors on the SIF-GPP relationship can contribute to the development of more accurate models for GPP estimation using SIF.
