干旱事件对华北落叶松和油松生态弹性的影响差异

Influences of drought events on ecological resilience of Larix principis-rupprechtii and Pinus tabulaeformis

为了探究干旱事件对人工林主要树种树木生长的影响,本研究以华北落叶松(Larix principis-rupprechtii)以及油松(Pinus tabulaeformis)人工林为研究对象,分析了2个树种径向生长对不同气候因子的响应以及单年、连年干旱事件影响下的生态弹性差异。结果表明:不同区域树种径向生长对气候因子和标准化降水蒸散指数(Standardized precipitation evaportranspiration index,SPEI)的响应存在差异,且与SPEI的相关性明显强于其他因子,随着干旱程度的增加华北落叶松的抵抗力稳定性呈现下降趋势,而油松较为稳定。单年干旱事件影响下的种间稳定性差异增大,连年干旱事件影响下的种间稳定性差异先增大后减小,在连年干旱事件的影响下,华北落叶松抵抗力明显下降,因此注重连年干旱下华北落叶松人工林的经营与管理,以保持其树木生长的稳定。

This study used Larix principis-rupprechtii and Pinus tabulaeformis plantation to explore the effects of drought events on the growth of main tree species in planted forest.The radial growth of two tree species were analyzed in response to different climatic factors and the differences of ecological elasticity were evaluated under the influence of single and successive drought events.The results showed that there were differences in the response of different tree species to regional climatic factors.Drought is the main limiting factor for the radial growth of trees in the study area.With the increase of drought intensity,the resistance stability of Larix principis-rupprechtii decreased while Pinus tabulaeformis showed stable resistance,and the difference of interspecific stability increased under the influence of annual drought events.The difference of interspecific stability under the influence of successive drought events increased at first and then decreased,and the resistance of Larix principis-rupprechtii decreased obviously under the influence of successive drought events.Therefore,we should pay attention to the management of Larix principis-rupprechtii plantation under continuous drought in order to maintain the stability of its tree growth.