Tree rings reveal a major episode of forest mortality in the late 18th century on the Tibetan Plateau
作 者：Fang OY, Alfaro RI, Zhang QB*
影响因子:3.915
刊物名称:Global and Planetary Change
出版年份:2018
卷:163期: 页码:44-50
文章摘要:There is a growing research interest on studying forest mortality in relation to ongoing climate warming, but little is known about such events in past history. The study of past forest mortality provides valuable information for determining baselines that establish the normal parameters of functioning inforest ecosystems. Here we report a major episode of previously undocumented forest mortality in the late 18th century on the northern Tibetan Plateau, China. The event was not spatially uniform, in which a more severe mortality happened in dryer sites. We useddendrochronologyto compare radial growth trajectories of individual trees from 11 sites in the region, and found that many trees showed positive growth trend, or growth release, during 1796–1800？CE. Growth releases are a proxy indicator of stand thinning caused by tree mortality. The growth release was preceded by an almost two-decade long growth reduction. Long-term drought related to weakenedNorth Atlantic Oscillationand frequentEl Ni？oevents are the likely factors causing the tree mortality in a large area of the plateau. Our findings suggest that, besides the effect of drought in the late 18th century, large-scale forest mortality may be an additional factor that further deteriorated the environment and increased the intensity ofdust storms.