Background:The relationship between climate and radial growth of trees exhibits spatial variation due to environ-mental changes.Therefore,elucidation of how the growth–climate responses of trees vary in space is esse...Background:The relationship between climate and radial growth of trees exhibits spatial variation due to environ-mental changes.Therefore,elucidation of how the growth–climate responses of trees vary in space is essential for understanding forest growth dynamics to facilitate scientific management with the ongoing global climate warming.To explore the altitudinal and slope variations of these interactions,tree-ring width chronologies of Larix olgensis A.Henry were analyzed in the southern Lesser Khingan Mountains,Northeast China.Results:The radial growth of L.olgensis exhibited significant 5-to 10-year periodic changes at three altitudes and two slopes,and the frequency change occurred mainly during the early growth stage and after 2000.The radial growth of L.olgensis was significantly negatively correlated with September precipitation only at low altitudes,but also with the mean temperature in July–August and the mean maximum temperature in June–August at high altitudes.The radial growth of L.olgensis at low and middle altitudes as well as on the sunny slope led to a higher demand for moisture,while temperature was the key limiting factor at high altitudes and on the shady slope.Conclusions:The climate–radial growth relationship of L.olgensis exhibits altitudinal and slope variability.This study quantitatively describes the spatially varying growth–climate responses of L.olgensis in the southern Lesser Khingan Mountains,which provides basic data for the management of L.olgensis forests and the prediction of future climate impacts on forest ecosystems.展开更多
In order to understand the management of regional vegetation,numerical classification and ordination are widely used to investigate community distribution and vegetation features.In particular,two-way indicator-specie...In order to understand the management of regional vegetation,numerical classification and ordination are widely used to investigate community distribution and vegetation features.In particular,two-way indicator-species analysis programs(TWINSPAN)classifies plots and species into different groups.De-trended correspondence analysis(DCA)and canonical correspondence analysis(CCA)reflects the relationship between community and site conditions.Afforestation with Larix olgensis Herry.Plantations is a suitable restoration strategy on post-agricultural fields in the Lesser Khingan Mountains.The results of this study show how these plantations develop over time to establish a reliable pathway model by measuring and clarifying the succession process.Twenty-eight L.olgensis plantations along a 48-year chronosequence of afforestation were investigated with a quadrat sampling method.Species composition,community structure attributes of diversity,and site conditions were analyzed.Communities were classified by TWINSPAN into five successional stages:immature,juvenile,mid-aged,nearmature and mature.Classifications were validated by DCA and CCA analysis.Site conditions such as soil and litter thickness,soil organic matter,soil density,and pH were measured.Successional stages varied in community composition and species population,accompanied by time from afforestation and a gradient of site conditions.This gradient showed changes in vegetation occurrence and diversity coinciding with changes in soil conditions.The study showed that L.olgensis plantations had marked predominance in growth and were associated with improved soil fertility and the formation of a stable plant community.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.31870620)the Fundamental Research Funds for the Central Universities(Grant No.PTYX202107).
文摘Background:The relationship between climate and radial growth of trees exhibits spatial variation due to environ-mental changes.Therefore,elucidation of how the growth–climate responses of trees vary in space is essential for understanding forest growth dynamics to facilitate scientific management with the ongoing global climate warming.To explore the altitudinal and slope variations of these interactions,tree-ring width chronologies of Larix olgensis A.Henry were analyzed in the southern Lesser Khingan Mountains,Northeast China.Results:The radial growth of L.olgensis exhibited significant 5-to 10-year periodic changes at three altitudes and two slopes,and the frequency change occurred mainly during the early growth stage and after 2000.The radial growth of L.olgensis was significantly negatively correlated with September precipitation only at low altitudes,but also with the mean temperature in July–August and the mean maximum temperature in June–August at high altitudes.The radial growth of L.olgensis at low and middle altitudes as well as on the sunny slope led to a higher demand for moisture,while temperature was the key limiting factor at high altitudes and on the shady slope.Conclusions:The climate–radial growth relationship of L.olgensis exhibits altitudinal and slope variability.This study quantitatively describes the spatially varying growth–climate responses of L.olgensis in the southern Lesser Khingan Mountains,which provides basic data for the management of L.olgensis forests and the prediction of future climate impacts on forest ecosystems.
基金We express our sincere appreciation to Xiao-Yu Guo,Yao Fu,Yu Dong,Tian-Bo Wang,Yi-Fu Wang for their fieldwork assistance,and to the members of Langxiang Forestry Bureau for their friendship and assistance.
文摘In order to understand the management of regional vegetation,numerical classification and ordination are widely used to investigate community distribution and vegetation features.In particular,two-way indicator-species analysis programs(TWINSPAN)classifies plots and species into different groups.De-trended correspondence analysis(DCA)and canonical correspondence analysis(CCA)reflects the relationship between community and site conditions.Afforestation with Larix olgensis Herry.Plantations is a suitable restoration strategy on post-agricultural fields in the Lesser Khingan Mountains.The results of this study show how these plantations develop over time to establish a reliable pathway model by measuring and clarifying the succession process.Twenty-eight L.olgensis plantations along a 48-year chronosequence of afforestation were investigated with a quadrat sampling method.Species composition,community structure attributes of diversity,and site conditions were analyzed.Communities were classified by TWINSPAN into five successional stages:immature,juvenile,mid-aged,nearmature and mature.Classifications were validated by DCA and CCA analysis.Site conditions such as soil and litter thickness,soil organic matter,soil density,and pH were measured.Successional stages varied in community composition and species population,accompanied by time from afforestation and a gradient of site conditions.This gradient showed changes in vegetation occurrence and diversity coinciding with changes in soil conditions.The study showed that L.olgensis plantations had marked predominance in growth and were associated with improved soil fertility and the formation of a stable plant community.
