Tree-grass coexistence in Savannas: The role of spatial dynamics and climate fluctuations
Ignacio Rodríguez-Iturbe
Princeton Environmental Institute and Water Resources and Environmental Engineering Program, Princeton University, New Jersey
Search for more papers by this authorPaolo D'Odorico
Princeton Environmental Institute and Water Resources and Environmental Engineering Program, Princeton University, New Jersey
Search for more papers by this authorAmilcare Porporato
Dipartimento di Idraulica, Trasporti e Infrastrutture Civili, Politecnico di Torino, Torino, Italy
Search for more papers by this authorLuca Ridolfi
Dipartimento di Idraulica, Trasporti e Infrastrutture Civili, Politecnico di Torino, Torino, Italy
Search for more papers by this authorIgnacio Rodríguez-Iturbe
Princeton Environmental Institute and Water Resources and Environmental Engineering Program, Princeton University, New Jersey
Search for more papers by this authorPaolo D'Odorico
Princeton Environmental Institute and Water Resources and Environmental Engineering Program, Princeton University, New Jersey
Search for more papers by this authorAmilcare Porporato
Dipartimento di Idraulica, Trasporti e Infrastrutture Civili, Politecnico di Torino, Torino, Italy
Search for more papers by this authorLuca Ridolfi
Dipartimento di Idraulica, Trasporti e Infrastrutture Civili, Politecnico di Torino, Torino, Italy
Search for more papers by this authorAbstract
The codominance of trees and grasses in savannas is explained as resulting from the minimization of vegetation stress. It is shown that under different climate, soil and vegetation conditions local interactions dictated by the spatial competition for soil moisture lead to an optimal state of minimum global water stress involving a stable coexistence of trees and grasses. The optimal state matches the observed canopy cover and soil moisture characteristics. Moreover, changes in canopy cover in the savanna environments are also suggested to result from climate fluctuations.
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