As part of an intensive study of crop response to CO 2 enrichment in a free-air CO2 enrichment (FACE) experiment in the field, we determined aspects of the water relations of a cotton crop on selected dates in 1991. The atmosphere was enriched from 370 #mol CO2 mo1-1 (control) to about 550 #mol mo1-1 in free air during daylight hours. Under full irrigation, CO2 enrichment decreased stomatal con...

Lippia citriodora H.B.K. is a valuable medicinal plant of Verbenaceae family. This study was calculated to evaluate potential role of salicylic acid (SA) in diminish the harmful effects of drought stress on L. citriodora plants. SA (0.5 and 1 mM) was used to L. citriodora plants grown under stressed (5, 10, 15 and 20% PEG) and unstressed conditions. Fresh weight (FW) and relative water content ...

Elevated atmospheric CO2 has been shown to rapidly alter plant physiology and ecosystem productivity, but contemporary evolutionary responses to increased CO2 have yet to be demonstrated in the field. At a Mojave Desert FACE (free-air CO2 enrichment) facility, we tested whether an annual grass weed (Bromus madritensis ssp. rubens) has evolved in response to elevated atmospheric CO2 . Within 7 y...

Soybean (Glycine max L. Merr. cv. Bragg), peanut (Arachis hypogaea L. cv. Georgia Green) and rice (Oryza saliva L. cv. IR-72) were grown for a full season in sunlit, controlled-environment chambers at 350 (ambient) and 700 (double-ambient, elevated) imol CO2 moF' air, and under daytime maximum/nighttime minimum air temperature regimes ranging from 28/18 to 48/38°C for soybean and peanut, or soi...

Bacterial and yeast endophytes isolated from the Salicaceae family have been shown to promote growth and alleviate stress in plants from different taxa. To determine the physiological pathways through which endophytes affect plant water relations, we investigated leaf water potential, whole-plant water use, and stomatal responses of rice plants to Salicaceae endophyte inoculation under CO2 enri...

Experimental evidence indicates that the stomatal conductance and nitrogen concentration ([N]) of foliage decline under CO2 enrichment, and that the percentage growth response to elevated CO2 is amplified under water limitation, but reduced under nitrogen limitation. We advance simple explanations for these responses based on an optimisation hypothesis applied to a simple model of the annual ca...

An open-top-chamber (OTC) CO2 enrichment (∼720μmol mol−1) study was conducted in the Colorado shortgrass steppe from April 1997 through October 2001. Aboveground plant biomass increased under elevated CO2 and soil moisture content was typically higher than under ambient CO2 conditions. Fluxes of CH4, CO2, NOx and N2O, measured weekly year round were not significantly altered by CO2 enrichment o...

The Earth's atmosphere will continue to be enriched with carbon dioxide (CO2) over the coming century. Carbon dioxide enrichment often reduces leaf transpiration, which in water-limited ecosystems may increase soil water content, change species abundances and increase the productivity of plant communities. The effect of increased soil water on community productivity and community change may be ...