Effects of elevation on spring phenological sensitivity to temperature in Tibetan Plateau grasslands
- 217 Downloads
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 °C increase in May average temperature at elevations from 3,000 to 3,500 m, while the rate was up to 8–9 days/°C 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.
KeywordsTemperature sensitivity Elevation Growth efficiency Land surface phenology Greenup Grasslands
This work was supported by the National Basic Research Program (CB951701), the External Cooperation Program of the Chinese Academy of Sciences (GJH21123), and the National Natural Science Foundation of China (40971197). We also thank CIAT for providing DEM data and Haiying Yu for useful comments.
Conflict of interest
The authors declare that they have no conflict of interest.
- 13.Hopkins AD (1920) The bioclimatic law. J Wash Acad Sci 10:34–40Google Scholar
- 21.Körner C (2004) Mountain biodiversity, its causes and function. Ambio 13:11–17Google Scholar
- 40.Zhang XS (2007) Vegetation map of the People’s Republic of China 1:1 000 000. The Geological Publishing House, Beijing (in Chinese)Google Scholar
- 45.Zhang GL, Zhang YJ, Dong JW et al (2013) Green-up dates in the Tibetan Plateau have continuously advanced from 1982 to 2011. Proc Natl Acad Sci USA 110:4309–4314Google Scholar
- 47.Liang L, Schwartz MD (2013) Testing a growth efficiency hypothesis with continental-scale phenological variations of common and cloned plants. Int J Biometeorol 1–9Google Scholar
- 52.Montague J, Barrett S, Eckert C (2008) Re-establishment of clinal variation in flowering time among introduced populations of purple loosestrife (Lythrum salicaria, Lythraceae). J Evol Biol 21:234–245Google Scholar
- 54.Liu LL, Liu LY, Hu Y (2012) Response of spring phenology to climate change across Tibetan Plateau. In: 2012 2nd International Conference on Remote Sensing, Environment and Transportation Engineering (RSETE 2012), Nanjing, June 2012. IEEE, Piscataway, NJ, USAGoogle Scholar
- 58.IPCC2007. Climate Change 2007: The Physical Science Basis: Summary for Policymakers. Intergovernmental Panel on Climate Change, Geneva, SwitzerlandGoogle Scholar
- 65.Willis CG, Ruhfel BR, Primack RB et al (2010) Favorable climate change response explains non-native species’ success in Thoreau’s woods. PLoS One 5:e8878Google Scholar