|
|
|
Evapotranspiration and Its Energy Exchange in Alpine Meadow Ecosystem on the Qinghai-Tibetan Plateau |
LI Jie, JIANG Sha, WANG Bin, JIANG Wei-wei, TANG Yan-hong, DU Ming-yuan , GU Song |
1.College of Life Science, Nankai University, Tianjin 300071, P.R.China
2.National Institute for Environmental Studies, Tsukuba 305-8506, Japan
3.National Institute for Agro-Environmental Sciences, Tsukuba 305-8604, Japan |
|
|
摘要 To understand the water and energy exchange on the Qinghai-Tibetan Plateau, we explored the characteristics of evapotranspiration (ET) and energy fluxes from 2002 to 2005 over a Kobresia meadow ecosystem using the eddy covariance method. The ratio of annual ET to precipitation (P) of meadow ecosystem was about 60%, but varied greatly with the change of season from summer to winter. The annual ET/P in meadow was lower than that in shrub, steppe and wetland ecosystems of this plateau. The incident solar radiation (Rs) received by the meadow was obviously higher than that of lowland in the same latitude; however the ratio of net radiation (Rn) to Rs with average annual value of 0.44 was significantly lower than that in the same latitude. The average annual ET was about 390 mm for 2002-2005, of which more than 80% occurred in growing season from May to September. The energy consumed on the ET was about 44% of net radiation in growing season, which was lower than that of shrub, steppe and wetland on this plateau. This study demonstrates that the Kobresia meadow may prevent the excessive water loss through evapotranspiration from the ecosystem into the atmosphere in comparison to the shrub, steppe and wetland ecosystems of the Qinghai-Tibetan Plateau.
Abstract To understand the water and energy exchange on the Qinghai-Tibetan Plateau, we explored the characteristics of evapotranspiration (ET) and energy fluxes from 2002 to 2005 over a Kobresia meadow ecosystem using the eddy covariance method. The ratio of annual ET to precipitation (P) of meadow ecosystem was about 60%, but varied greatly with the change of season from summer to winter. The annual ET/P in meadow was lower than that in shrub, steppe and wetland ecosystems of this plateau. The incident solar radiation (Rs) received by the meadow was obviously higher than that of lowland in the same latitude; however the ratio of net radiation (Rn) to Rs with average annual value of 0.44 was significantly lower than that in the same latitude. The average annual ET was about 390 mm for 2002-2005, of which more than 80% occurred in growing season from May to September. The energy consumed on the ET was about 44% of net radiation in growing season, which was lower than that of shrub, steppe and wetland on this plateau. This study demonstrates that the Kobresia meadow may prevent the excessive water loss through evapotranspiration from the ecosystem into the atmosphere in comparison to the shrub, steppe and wetland ecosystems of the Qinghai-Tibetan Plateau.
|
Received: 17 October 2012
Accepted:
|
Fund: This study was supported by the National Natural Science Foundation of China (31070433) and Japan-China Research Cooperative Program (2010DFA31290). This study was also partly supported by the project of Early Detection and Prediction of Climate Warming Based on the Long- Term Monitoring of Alpine Ecosystems on the Tibetan Plateau funded by the Ministry of Environment, Japan. |
Corresponding Authors:
Correspondence GU Song, Tel: +86-22-23508245, E-mail: songgu@nankai.edu.cn
E-mail: songgu@nankai.edu.cn
|
Cite this article:
LI Jie, JIANG Sha, WANG Bin, JIANG Wei-wei, TANG Yan-hong, DU Ming-yuan , GU Song.
2013.
Evapotranspiration and Its Energy Exchange in Alpine Meadow Ecosystem on the Qinghai-Tibetan Plateau. Journal of Integrative Agriculture, 12(8): 1396-1401.
|
[1]Cao G M, Li Y N, Bao X K. 1998. Water-retentioncharacteristics of mat cryo-sod soil in high frigidregions. Soils, 1, 27-30 (in Chinese)Cui X F, Graf H F 2009. Recent land cover changes on theTibetan Plateau: A review. Climatic Change, 94, 47-61[2]Gu S, Tang Y H, Du M Y, Kato T, Li Y N, Cui X Y, Zhao X Q.2003. Short-term variation of CO2 flux in relation toenvironmental controls in an alpine meadow on theQinghai-Tibetan Plateau. Journal of GeophysicalResearch, 108, D21, 4670. doi: 10.1029/2003JD003584[3]Gu S, Tang Y H, Cui X Y, Kato T, Du M Y, Li Y N, Zhao X Q.2005. Energy exchange between the atmosphere and ameadow ecosystem on the Qinghai-Tibetan Plateau.Agricultural and Forest Meteorology, 129, 175-185[4]Gu S, Tang Y H, Cui X Y, Du M Y, Zhao L, Li Y N, Xu S X,Zhou H K, Kato T, Qi P T, et al 2008. Characterizingevapotranspiration over a meadow ecosystem on theQinghai-Tibetan Plateau. Journal of GeophysicalResearch, 113, D08118. doi: 10.1029/2007JD009173[5]Hammerle A, Haslwanter A, Tappeiner U, Cernusca A,Wohlfahrt G. 2008. Leaf area controls on energypartitioning of a temperate mountain grassland.Biogeosciences, 5, 421-431[6]Hao Y B, Wang Y F, Huang X Z, Cui X Y, Zhou X Q, WangS P, Niu H S, Jiang G M. 2007. Seasonal and interannualvariation in water vapor and energy exchange over atypical steppe in Inner Mongolia, China. Agriculturaland Forest Meteorology, 146, 57-69[7]Hu Z M, Yu G R, Zhou Y L, Sun X M, Li Y N, Shi P L, WangY F, Song X, Zheng Z M, Zhang L, et al. 2009. Partitioning of evapotranspiration and its controls in fourgrassland ecosystem: application of a two-sourcemodel. Agricultural and Forest Meteorology, 149,1410-1420[8]Hunt J E, Kelliher F M, McSeveny T M, Byers J N. 2002.Evaporation and carbon dioxide exchange between theatmosphere and a tussock grassland during a summerdrought. Agricultural and Forest Meteorology, 111,65-82[9]Kato T, Tang Y H, Gu S, Hirota M, Cui X Y, Du M Y, Li Y N,Zhao X Q, Oikawa T. 2004. Seasonal patterns of grossprimary production and ecosystem respiration in analpine meadow ecosystem on the Qinghai-TibetanPlateau. Journal of Geophysical Research, 109,D12109. doi: 10.1029/2003JD003951[10]Li S G, Lai C T, Lee G, Shimoda S, Yokoyama T, Higuchi A,Oikawa T. 2005. Evapotranspiration from a wettemperate grassland and its sensitivity tomicroenvironmental variables. Hydrological Processes,19, 517-532[11]Liu S, Li S G, Yu G R, Sun X M, Zhang L M, Hu Z M, Li Y N,Zhang X Z 2009. Surface energy exchanges above twograssland ecosystems on the Qinghai-Tibetan Plateau.Biogeosciences Discussions, 6, 9161-9193[12]Liu S, Li S G, Yu G R, Sun X M, Zhang L M, Michiaki S, Li YN, Zhang X Z, Wang Y F. 2010. Surface energyexchanges in grassland ecosystems along aprecipitation gradient. Acta Ecologica Sinica, 30, 557-567[13](in Chinese)Malhi Y, Pegoraro E, Nobre A D, Pereira M G P, Grace J,Culf A D, Clement R. 2002. The energy and waterdynamics of a central Amazonian rain forest. Journalof Geophysical Research, 107, D20, 8061. doi: 10.1029/2001JD000623[14]Mitchell P J, Veneklaas E, Lambers H, Stephen S O B. 2009.Partitioning of evapotranspiration in a semi-arideucalypt woodland in south-western Australia.Agricultural and Forest Meteorology, 149, 25-37[15]Rosenberg N J, Blad B L, Verma S B. 1983. Microclimate:the Biological Environment. John Wiley & Sons, NewYork. p. 315.Shi S B, Ben G Y, Han F, Li Y N, Shen Z X. 2001. Plantgrowth analysis of Kobresia humilis meadowcommunity in Qingzang Plateau regions. ActaEcologica Sinica, 21, 871-876[16](in Chinese)Wever L A, Flanagan L B, Carlson P J. 2002. Seasonal andinterannual variation in evapotranspiration, energybalance and surface conductance in a northerntemperate grassland. Agricultural and ForestMeteorology, 112, 31-49[17]Zhang X C, Gu S, Zhao X Q, Cui X Y, Zhao L, Xu S X, Du MY, Jiang S, Gao Y B, Ma C, et al. 2010. Radiationpartitioning and its relation to environmental factorsabove a meadow ecosystem on the Qinghai-TibetanPlateau. Journal of Geophysical Research, 115, D10106.doi: 10.1029/2009JD012373 |
No Suggested Reading articles found! |
|
|
Viewed |
|
|
|
Full text
|
|
|
|
|
Abstract
|
|
|
|
|
Cited |
|
|
|
|
|
Shared |
|
|
|
|
|
Discussed |
|
|
|
|