in present world, inequality and uncertainty is high in section of agriculture production and food security of a great amount of people in developing countries is not supplied. based on studies of international organizations, about a third of produced food for human consumption in worldwide is lost or wasted. while in developing countries, there is price enhancement, decrease in access to healt...

Although the global partitioning of evapotranspiration (ET) into transpiration, soil evaporation, and canopy evaporation is not well known, most current land surface schemes and the few available observations indicate that transpiration is the dominant component on the global scale, followed by soil evaporation and canopy evaporation. The Community Land Model version 3 (CLM3), however, does not...

For years, the principal objective of evapo-transpiration research has been to calculate the loss of water under varying conditions of climate, soil, and vegetation. The early simple empirical methods have generally been replaced by more detailed models which more closely represent the physical and biological processes involved. Monteith's modification of the original Penman This paper is not s...

The terrestrial hydrological cycle is strongly influenced by transpiration--water loss through the stomatal pores of leaves. In this report we present studies showing that the energy content of radiation absorbed by the leaf influences stomatal control of transpiration. This observation is at odds with current concepts of how stomata sense and control transpiration, and we suggest an alternativ...

The weather patterns of the west side of the Sierra Nevada Mountains (cold, wet winters and hot, dry summers) strongly influence how water is partitioned between transpiration and evaporation and result in a specific strategy of water use by ponderosa pine trees (Pinus ponderosa) in this region. To investigate how year-round water fluxes were partitioned in a young ponderosa pine ecosystem in t...

We discuss a simplifed, conceptual model for the dynamics of the soil-vegetation system in drylands. The model considers the different dynamical processes taking place in vegetated and non-vegetated soil and it distinguishes between the upper soil layer, where rapid evaporation dominates, and the deeper root layer where only plant transpiration takes place. We explore the role of rainfall inter...

Literature regarding evaporation from soil, wet plant surfaces, and sprinkler droplets was examined, normalized, and inter­ preted. Much of the evaporation literature is difficult to compare and interpret; this paper offers comparisons and discussions of various findings by others as well as by the writers. Techniques of measuring and estimating evaporation from irrigation and rainfall are disc...

Soil evaporation can signifi cantly infl uence energy fl ux partitioning of partially vegetated surfaces, ultimately affecting plant transpiration. While important, quantifi cation of soil evaporation, separately from canopy transpiration, is challenging. Techniques for measuring soil evaporation exist and continually improve. The large variability in soil water content requires that there be c...