Global separation of plant transpiration from groundwater and streamflow

摘要: Current land surface models assume that groundwater, streamflow and plant transpiration are all sourced mediated by the same well mixed water reservoir--the soil. However, recent work in Oregon Mexico has shown evidence of ecohydrological separation, whereby different subsurface compartmentalized pools supply either fluxes or combined groundwater streamflow. These findings have not yet been widely tested. Here we use hydrogen oxygen isotopic data ((2)H/(1)H (δ(2)H) (18)O/(16)O (δ(18)O)) from 47 globally distributed sites to show separation is widespread across biomes. Precipitation, stream each site plot approximately along δ(2)H/δ(18)O slope local precipitation inputs. But soil xylem waters extracted below on meteoric line, suggesting plants does itself contribute recharge Our results further that, at 80% sites, supplies parts transpiration. The ubiquity compartmentalization found here, segregation storm types relative hydrological ecological fluxes, may be used improve numerical simulations runoff generation, transit time evaporation-transpiration partitioning. Future model parameterizations should closely examined for how vegetation, assumed coupled.