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Ecological optimality in water‐limited natural soil‐vegetation systems: 2. Tests and applications
Author(s) -
Eagleson Peter S.,
Tellers Tobin E.
Publication year - 1982
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/wr018i002p00341
Subject(s) - climax , evapotranspiration , climax community , vegetation (pathology) , environmental science , canopy , surface runoff , soil science , porosity , hydrology (agriculture) , bulk density , water content , soil water , ecology , ecological succession , geology , geotechnical engineering , biology , pathology , medicine
The long‐term optimal climatic climax soil‐vegetation system is defined for several climates according to previous hypotheses in terms of two free parameters, effective porosity and plant water use coefficient. The free parameters are chosen by matching the predicted and observed average annual water yield. The resulting climax soil and vegetation properties are tested by comparison with independent observations of canopy density and average annual surface runoff. The climax properties are shown also to satisfy a previous hypothesis for short‐term optimization of canopy density and water use coefficient. Using these hypotheses, a relationship between average evapotranspiration and optimum vegetation canopy density is derived and is compared with additional field observations. An algorithm is suggested by which the climax soil and vegetation properties can be calculated given only the climate parameters and the soil effective porosity. Sensitivity of the climax properties to the effective porosity is explored.