Net radiation rather than surface moisture limits evapotranspiration over a humid alpine meadow on the northeastern Qinghai-Tibetan Plateau

The Qinghai-Tibetan Plateau (QTP) is generally considered to be the water source region for its surrounding lowlands. However, there have only been a few studies that have focused on quantifying alpine meadow evapotranspiration (ET) and its partitioning, which are important components of water balance. This paper used the Shuttleworth–Wallace (S–W) model to quantify soil evaporation (E) and plant transpiration (T) in a degraded alpine meadow (34°24′ N, 100°24′ E, 3963 m a.s.l) located at the QTP from September 2006 to December 2008. The results showed that the annual ET estimated by the S–W model (ETSW) was 511.5 mm (2007) and 499.8 mm (2008), while E estimated by the model (ESW) was 306.0 mm and 281.7 mm for 2007 and 2008, respectively, which was 49% and 29% higher than plant transpiration (TSW). Model analysis showed that ET, E, and T were mainly dominated by net radiation (Rn), while leaf area index (LAI) and soil water content at a 5 cm depth (SWC5cm) were the most important factors influencing ET partitioning. The study results suggest that meadow degradation may increase water loss through increasing E, and reduce the water conservation capability of the alpine meadow ecosystem.

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Microbial Communities of Alpine Meadow Soil in the Eastern Qinghai-Tibetan Plateau Subjected to Experimental Warming and Grazing*

Chinese Journal of Appplied Environmental Biology ◽

10.3724/sp.j.1145.2011.00151 ◽

2012 ◽

Vol 17 (2) ◽

pp. 151-157 ◽

Cited By ~ 2

Author(s):

Bei WANG ◽

Geng SUN ◽

Peng LUO ◽

Zhiyuan WANG ◽

Yanbo ZHANG ◽

...

Keyword(s):

Tibetan Plateau ◽

Microbial Communities ◽

Alpine Meadow ◽

Meadow Soil ◽

Experimental Warming

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4Flowering Responses of Alpine Meadow Plant in the Qinghai-Tibetan Plateau to Extreme Drought Imposed in Different Periods

Chinese Journal of Appplied Environmental Biology ◽

10.3724/sp.j.1145.2013.00272 ◽

2013 ◽

Vol 19 (2) ◽

pp. 272-279 ◽

Cited By ~ 4

Author(s):

Chengxiang MOU ◽

Geng SUN ◽

Peng LUO ◽

Zhiyuan WANG ◽

Guangrong LUO

Keyword(s):

Tibetan Plateau ◽

Alpine Meadow ◽

Extreme Drought

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Annual Variability in Summer Evapotranspiration and Water Balance at a Subarctic Forest Site

Hydrology Research ◽

10.2166/nh.1994.0012 ◽

1994 ◽

Vol 25 (5) ◽

pp. 331-344 ◽

Cited By ~ 8

Author(s):

Peter M. Lafleur

Keyword(s):

Water Balance ◽

Daily Precipitation ◽

The Other ◽

Forest Site ◽

Net Radiation ◽

Atmospheric Conditions ◽

Surface Moisture ◽

Equilibrium Evaporation ◽

Subarctic Forest ◽

Single Regression

Evapotranspiration (ET) and precipitation were measured during five summers (1989-1993 inclusive) at a subarctic forest site near Churchill, Manitoba, Canada. Mean daily ET varied from 2.14-3.18 mm d−1 during the five summers, while mean daily precipitation (P) ranged from 1.46-3.15 mm d−1. Yearly variability in summer ET was most influenced by availability of surface moisture, then by atmospheric conditions (i.e. temperature), and least of all by net radiation. In four of the five years total summer ET exceeded P resulting in significant soil water deficits and in the other year summer ET and P were similar in magnitude. The use of equilibrium evaporation (EE) as a predictor of ET was explored. Separate relationships between ET and EE were computed for all five years. Three statistically dissimilar groups of equations were found: 1989/1990, 1991/ 1992, and 1993. A single regression equation describing all years is presented.

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