Reconstruction of disturbance history on Juniperus przewalskii forests in middle Qilian Mountains
Aims The reconstruction of regional disturbance history provides important information in understanding the health status of local forests and facilitating their management and protection.However,the history and regimes of disturbances in the Qilian Mountains remain poorly reported.Methods In this study,we explored the disturbance history of Juniperus przewalskii,a dominant tree species on the sunny slope of the Qilian Mountains.Tree-ring cores were collected and the standard chronologies of tree-ring width from eight sites were established.We analyzed the correlation between climate factors and tree-ring index.By calculating the percentage growth change in each tree,we examined whether there had been tree-growth release or suppression,thereby identifying the historical course and spatial pattern of disturbances.Important findings Winter air temperature and summer moisture conditions significantly affected the growth of the tree species.The reconstruction of disturbance history highlighted two major forest disturbance events that occurred during the 1930s and 1970s in our study area.These events were intimately linked to extreme cold winters and severe summer droughts,coinciding remarkably with the occurrence of El Nino.Both events showed spatial variability in disturbance,reflecting differences in resistance across forests.Our study results offer new perspectives in mitigating forest degradation and enhancing forest management in the future.
tree ringgrowth releasegrowth suppressionextreme climateQilian Mountains
万方数据
维普
