Effects of elevation on spring phenological sensitivity to temperature in Tibetan Plateau grasslands

作     者：Lingling Liu Liangyun Liu Liang Liang Alison Donnelly Isaac Park Mark D.Schwartz 

作者机构：Institute of Remote Sensing and Digital Earth Chinese Academy of Sciences University of Chinese Academy of Sciences Department of Geography University of Wisconsin-MilwaukeeMilwaukee WI 53201-0413 USA Department of Geography University of Kentucky LexingtonKY 40506-0027 USA 

出 版 物：《Chinese Science Bulletin》 (科学通报(英文版))

年 卷 期：2014年第59卷第34期

页      面：4856-4863页

核心收录：

学科分类：07[理学] 070601[理学-气象学] 0706[理学-大气科学] 

基　　金：supported by the National Basic Research Program(CB951701) the External Cooperation Program of the Chinese Academy of Sciences(GJH21123) the National Natural Science Foundation of China(40971197) 

主　　题：植被物候 海拔高度 温度数据 青藏高原 敏感性 草原 气候变化影响 高山生态系统 

摘      要：Vegetation phenology is an important indicator of climate change impacts on the seasonal dynamics of the biosphere. However, little is known about the influence of elevation on spring phenological sensitivity to temperature in an alpine ecosystem. Based on remotely sensed land surface phenology and temperature data from 2001 to2010, this study investigated the rate of spring phenological change of the Tibetan Plateau(TP) grasslands in response to interannual temperature variations at different elevations. Results suggest that spring phenology in the TP grasslands exhibits a stronger response to changes in temperature at higher elevations than at lower ones. In particular, spring phenology advanced by 1–2 days in response to a 1 °C increase in May average temperature at elevations from 3,000 to 3,500 m, while the rate was up to8–9 days/°C at 5,000–5,500 m. Analysis using accumulated growing degree days(AGDD) from January 1through May 31 showed the same general trend with increased elevation associated with increased sensitivity(as measured by phenological change per unit of AGDDchange). Such temperature sensitivity gradients in the TP grasslands could be partly explained by the growth efficiency hypothesis which suggests that vegetation adapted to colder climates likely requires less heat energy for the onset of growing season and vice versa in warmer ***, accumulated growing degree days from January 1 to the greenup date were found to decrease with increasing elevations, which provided evidence to support the applicability of the growth efficiency hypothesis in an alpine grassland ecosystem.