中文摘要：

植被物候学是生物圈的季节的动力学上的气候变化影响的重要指示物。然而，很少在一个高山的生态系统对对春天 phenological 敏感的举起的影响被知道到温度。从 2001 ～ 2010 基于遥远地察觉到的陆地表面物候学和温度数据，这研究在不同举起响应 interannual 温度变化调查了西藏的高原(TP ) 草地的春天 phenological 变化的率。结果建议在 TP 草地的那春天物候学比在更低的点在更高的举起在温度展出更强壮的回答到变化。特别地，春天物候学到 12 天进展了响应一 1 ? 桴ǐ

英文摘要：

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 to 2010, 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 ℃ increase in May average temperature at elevations from 3,000 to 3,500 m, while the rate was up to 8-9 days/℃ at 5,000-5,500 m. Analysis using accumulated growing degree days （AGDD） from January 1 through May 31 showed the same general trend with increased elevation associated with increased sensitivity （as measured by phenological change per unit of AGDD change）. 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 climates. Furthermore, 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.