Modeling the ecohydrological role of aspect-controlled 4 radiation on tree-grass-shrub coexistence in a semiarid climate 5 6 7

7 Xiaochi Zhou 2 Erkan Istanbulluoglu * and Enrique R. Vivoni 4 8 9 10 1. Department of Civil and Environmental Engineering, 11 University of Washington, Seattle, WA 98195, USA 12 13 2. Department of Civil and Environmental Engineering, 14 Duke University, Durham, NC 27708, USA 15 16 3. School of Earth and Space Exploration, 17 Arizona State University, Tempe, AZ, 85287, USA 18 19 4. School of Sustainable Engineering and the Built Environment, 20 Arizona State University, Tempe, AZ, 85287, USA 21 22 Submitted to Water Resources Research 23 July 06, 2011 24 25 26 27 28 29 30 31 32 33 34

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