Publication Date:
2013-01-25
Description:
We study the interaction between climate and vegetation on an ideal water-limited planet, focussing on the influence of vegetation on the global water cycle. We introduce a simple mechanistic box model consisting in a two-layer representation of the atmosphere and a two-layer soil scheme. The model includes the dynamics of vegetation cover, and the main physical processes of energy and water exchange among the different components. With a realistic choice of parameters, this model displays three stable equilibria, depending on the initial conditions of soil water and vegetation cover. The system reaches a hot and dry state for low values of initial water content and/or vegetation cover, while we observe a wet, vegetated state with mild surface temperature when the system starts from larger initial values of both variables. The third state is a cold desert, where plants transfer enough water to the atmosphere to start a weaker, evaporation-dominated water cycle before they wilt. These results indicate that in this system vegetation plays a central role in transferring water from the soil to the atmosphere and trigger a hydrologic cycle. The model adopted here can also be used to conceptually illustrate processes and feedbacks affecting the water cycle in water-limited continental areas on Earth. Keywords: climatevegetation interactions, multiple stable states, water cycle, zero-dimensional models, evapotranspiration (Published: 24 January 2013) Citation: Tellus B 2013, 65 , 17662, http://dx.doi.org/10.3402/tellusb.v65i0.17662 To access the supplementary material to this article, please see Supplementary files in the column to the right (under Article Tools)
Print ISSN:
0280-6509
Electronic ISSN:
1600-0889
Topics:
Geography
,
Physics
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