transpiration, as one of the components of hydrological cycle, has not been paid enough attention yet, while it is necessary for sound utilization of rangelands, mostly located in the arid and semiarid regions. the comparison of the different kinds of rangelands species in terms of transpiration rates provides range managers the required information to achieve optimal forage production for a gi...

Previous studies suggest that the radiative effects of atmospheric aerosols (reducing total radiation while increasing the diffuse fraction) can enhance terrestrial productivity. Here, simulations using a regional climate/terrestrial biosphere model suggest that atmospheric aerosols could also enhance terrestrial photosynthesis and transpiration through an interaction between solar radiation, l...

Increased tomato fruit quality in response to increased salinity is well documented (Li, 2000). However, the increased fruit quality is achieved at the expenses of severe yield losses mostly due to reduced fruit size (fresh weight) and increased incidence of physiological disorders such as blossom end rot (BER). The ability to minimize the negative effects of high salinity at the root level, wh...

Most mercury emission inventories only include anthropogenic emissions and neglect the large contribution of the natural mercury cycle due to difficulty in spatially estimating natural emissions and uncertainties in the natural emissions process. The Mercury (Hg) Surface Interface Model (HgSIM) has been developed to estimate the natural emissions of mercury, for inclusion in a more complete mer...

The high altitude spruce—fir (Abies fraseri (Pursh) Poiret.—Picea rubens Sarg.) forests of the southern Appalachian Mountains. USA, experience frequent cloud immersion. Recent studies indicate that cloud bases may have risen over the past 30 years, resulting in less frequent forest cloud immersion, and that further increases in cloud base height are likely in the event of continued climate warm...

Root hydraulic conductivity in plants (Lp(r)) exhibits large variations in response to abiotic stimuli. In this study, we investigated the impact of dynamic, aquaporin-mediated changes of Lp(r) on leaf growth, water potential, and water flux throughout the plant. For this, we manipulated Lp(r) by subjecting roots to four independent treatments, with aquaporin inhibitors applied either to transp...

Objectives Prediction of climate change impacts on terrestrial carbon fluxes is highly uncertain. Upland ecosystem models, even when constrained with flux tower data, fail to explain interannual variability in CO2 fluxes in the upper Midwest. One possible reason is lack of model mechanisms for wetland biogeochemistry and hydrology, where fluxes would be expected to vary with changes in depth to...

Under conditions of high vapor pressure deficit (VPD) and soil drying, restricting transpiration is an important avenue to gain efficiency in water use. The question we raise in this article is whether breeding for agro-ecological environments that differ for the rainfall have selected for traits that control plant water use. These are measured in pearl millet materials bred for zones varying i...

Productivity of conifers in seasonally snow-covered forests is high before and during snowmelt when environmental conditions are optimal for photosynthesis. Climate change is altering the timing of spring in many locations, and changes in the date of transition from winter dormancy can have large impacts on annual productivity. Sap flow methods provide a promising approach to monitor tree activ...

We measured sap flux in Pinus ponderosa Laws. and Pinus flexilis James trees in a high-elevation meadow in northern Arizona that has been invaded by conifers over the last 150 years. Sap flux and environmental data were collected from July 1 to September 1, 2000, and used to estimate leaf specific transpiration rate (El), canopy conductance (Gc) and whole-plant hydraulic conductance (Kh). Leaf ...