文章摘要：
The alpine treeline is commonly regarded as being sensitive to climatic warming because regeneration and growth of trees at treeline generally are limited by low temperature. The alpine treelines of the Tibetan Plateau (TP) occur at the highest elevations (4,900 m above sea level) in the Northern Hemisphere. Ongoing climatic warming is expected to shift treelines upward. Studies of treeline dynamics at regional and local scales, however, have yielded conflicting results, indicating either unchanging treeline elevations or upward shifts. To reconcile this conflict, we reconstructed in detail a century of treeline structure and tree recruitment at sites along a climatic gradient of 4 °C and mean annual rainfall of 650 mm on the eastern TP. Species interactions interacted with effects of warming on treeline and could outweigh them. Densification of shrubs just above treeline inhibited tree establishment, and slowed upward movement of treelines on a time scale of decades. Interspecific interactions are major processes controlling treeline dynamics that may account for the absence of an upward shift at some TP treelines despite continued climatic warming.
文章信息：
Species interactions slow warming-induced upward shifts of treelines on the Tibetan Plateau
Eryuan Liang, Yafeng Wang, Shilong Piao, Xiaoming Lu, Jesús Julio Camarero, Haifeng Zhu, Liping Zhu, Aaron M. Ellison, Philippe Ciais, and Josep Peñuelasg
Edited by Christopher B. Field, Carnegie Institution of Washington, Stanford, CA, and approved March 3, 2016 (received for review October 19, 2015)
