Water-Use Efficiency of the Terrestrial Biosphere: A Model Analysis Focusing on Interactions between the Global Carbon and Water Cycles
Open Access
- 1 April 2012
- journal article
- Published by American Meteorological Society in Journal of Hydrometeorology
- Vol. 13 (2), 681-694
- https://doi.org/10.1175/jhm-d-10-05034.1
Abstract
Carbon and water cycles are intimately coupled in terrestrial ecosystems, and water-use efficiency (WUE; carbon gain at the expense of unit water loss) is one of the key parameters of ecohydrology and ecosystem management. In this study, the carbon cycle and water budget of terrestrial ecosystems were simulated using a process-based ecosystem model called Vegetation Integrative Simulator for Trace Gases (VISIT), and WUE was evaluated: WUEC, defined as gross primary production (GPP) divided by transpiration; and WUES, defined as net primary production (NPP) divided by actual evapotranspiration. Total annual WUEC and WUES of the terrestrial biosphere were estimated as 8.0 and 0.92 g C kg−1 H2O, respectively, for the period 1995–2004. Spatially, WUEC and WUES were only weakly correlated. WUES ranged from 1.5 g C kg−1 H2O in boreal and alpine ecosystems. The historical simulation implied that biospheric WUE increased from 1901 to 2005 (WUEC, +7%; WUES, +12%) mainly as a result of the augmentation of productivity in parallel with the atmospheric carbon dioxide increase. Country-based analyses indicated that total NPP is largely determined by water availability, and human appropriation of NPP is also related to water resources to a considerable extent. These results have implications for 1) responses of the carbon cycle to the anticipated global hydrological changes, 2) responses of the water budget to changes in the terrestrial carbon cycle, and 3) ecosystem management based on optimized resource use.Keywords
This publication has 66 references indexed in Scilit:
- How climate and vegetation type influence evapotranspiration and water use efficiency in Canadian forest, peatland and grassland ecosystemsAgricultural and Forest Meteorology, 2012
- Ecosystem stewardship: sustainability strategies for a rapidly changing planetTrends in Ecology & Evolution, 2010
- Simulations of global evapotranspiration using semiempirical and mechanistic schemes of plant hydrologyGlobal Biogeochemical Cycles, 2009
- Temporal and among‐site variability of inherent water use efficiency at the ecosystem levelGlobal Biogeochemical Cycles, 2009
- Projected increase in continental runoff due to plant responses to increasing carbon dioxideNature, 2007
- Mean annual GPP of Europe derived from its water balanceGeophysical Research Letters, 2007
- Global response of terrestrial ecosystem structure and function to CO2 and climate change: results from six dynamic global vegetation modelsGlobal Change Biology, 2001
- Net CO2 and H2O fluxes of terrestrial ecosystemsGlobal Biogeochemical Cycles, 1999
- Comparing global models of terrestrial net primary productivity (NPP): overview and key resultsGlobal Change Biology, 1999
- Stomatal Behaviour and EnvironmentPublished by Elsevier BV ,1978