Soil moisture plays a key role in most environmental processes, as evaporation and transpiration are heavily dependent on soil moisture variability. While it is one of the few important hydrological variables that can be directly observed, the high spatial and temporal variability makes it difficult to measure globally or even regionally. Reliance is therefore placed on land surface models to p...

The Sound attenuation and dispersion in saturated gas-vapor-droplet mixtures with evaporation has been investigated theoretically. The theory is based on an extension of the work of Davidson (1975) to accommodate the effects of transpiration on the linear particle relaxation processes of mass, momentum and energy transfer. It is shown that the inclusion of transpiration in the presence of mass ...

Previous work in climatically similar sagebrush steppe, USA and Patagonian steppe, Argentina suggested that a more intense evolutionary history of grazing in Patagonia selected for graminoids of lower forage quality, resulting in a plant community more resistant to livestock grazing. Here we consider whether subtle abiotic differences might create greater water or nutrient limitation in Patagon...

Grasshoppers of the species Schistocerca nitens (Thiinberg), Locusta migratoria (L.) and Tmethis pulchripennis (Bolivar) are able to withstand air temperatures higher than lethal internal temperature (48 °C) for more than an hour, during which time they maintain an internal temperature as much as 8°C below air temperature. Rates of evaporation at high air temperatures are much greater than thos...

Transpiration from a hawthorn (Crataegus monogyna L.) dominated hedgerow in southern England was measured continuously over two growing seasons by the sap flow technique. Accompanying measurements of structural parameters, microclimate and leaf stomatal and boundary layer conductances were used to establish the driving factors of hedgerow transpiration. Observed transpiration rates, reaching pe...

The relative contributions of overstory and understory plant transpiration and soil evaporation to total evapotranspiration (ET) in a semiarid savanna woodland were determined from stable isotope measurements of atmospheric water vapor. The savanna overstory was dominated by the deeply rooted, woody legume Prosopis velutina (“mesquite”), and the understory was dominated by a perennial C4 grass,...

Numerous studies have addressed effects of rising atmospheric CO2 concentration on rice biomass production and yield but effects on crop water use are less well understood. Irrigated rice evapotranspiration (ET) is composed of floodwater evaporation and canopy transpiration. Crop coefficient Kc (ET over potential ET, or ETo) is crop specific according to FAO, but may decrease as CO2 concentrati...