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.
Liang, E., Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China, Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China, CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, 100101, China; Wang, Y., Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China; Piao, S., Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China, CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, 100101, China; Lu, X., Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China; Camarero, J.J., Instituto Pirenaico de EcologÃ-a, Consejo Superior de Investigaciones CientÃ-ficas (IPE-CSIC), Zaragoza, 50059, Spain; Zhu, H., Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China; Zhu, L., Key Laboratory of Tibetan Environment Changes and Land Surface Processes, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing, 100101, China, CAS Center for Excellence in Tibetan Plateau Earth Sciences, Beijing, 100101, China; Ellison, A.M., Harvard Forest, Petersham, MA 01366, United States; Ciais, P., Laboratoire des Sciences du Climat et de l'Environnement, Commissariat A l'Energie Atomique CNRS, L'Universitã de Versailles Saint-Quentin, Gif sur Yvette, 91191, France; Peñuelas, J., CSIC, Global Ecology Unit, Centre de Recerca Ecologica i Aplicacions Forestals (CREAF)-CSIC-UAB, Cerdanyola Del Valles, Catalonia, E-08193, Spain, CREAF, Cerdanyola del Valles, Catalonia, E-08193, Spain
Recommended Citation:
Liang E.,Wang Y.,Piao S.,et al. Species interactions slow warming-induced upward shifts of treelines on the Tibetan Plateau[J]. Proceedings of the National Academy of Sciences of the United States of America,2016-01-01,113(16)