The Prairie Heating and CO2 Enrichment (PHACE) experiment has been initiated at a site in southern Wyoming (USA) to simulate the impact of warming and elevated atmospheric CO2 on ecosystem dynamics for semiarid grassland ecosystems. The DAYCENT ecosystem model was parametrized to simulate the impact of elevated CO2 at the open-top chamber (OTC) experiment in north-eastern Colorado (1996-2001), ...

Studies of responses of forest vegetation to steadily increasing atmospheric concentrations of CO2 have focussed strongly on the potential of trees to absorb extra carbon; the effects of elevated [CO2] on plant–soil water relations via decreased stomatal conductance and increased ambient temperature have received less attention, but may be significant in the long term at the ecosystem level. CO...

The effects of CO2 enrichment on the growth and physiology of maize were investigated at the molecular, biochemical, leaf, and canopy levels. Maize plants were grown in sunlit soil–plant–atmosphere research (SPAR) chambers at ambient (370 lmol mol ) or elevated (750 lmol mol ) atmospheric carbon dioxide concentration (Ca) under wellwatered and fertilized conditions. Canopy gas exchange rates an...

A regional climate change model (PRECIS) for China, developed by the UK's Hadley Centre, was used to simulate China's climate and to develop climate change scenarios for the country. Results from this project suggest that, depending on the level of future emissions, the average annual temperature increase in China by the end of the twenty-first century may be between 3 and 4 degrees C. Regional...

* Greater fine-root production under elevated [CO2] may increase the input of carbon (C) and nitrogen (N) to the soil profile because fine root populations turn over quickly in forested ecosystems. * Here, the effect of elevated [CO)] was assessed on root biomass and N inputs at several soil depths by combining a long-term minirhizotron dataset with continuous, root-specific measurements of roo...

We investigated the effects of CO2 enrichment on fine root chemical composition of two tree species common to northern hardwood forests. Two-year-old Betula papyrifera and 3-year-old Acer saccharum saplings were grown under ambient (400 μmol·mol–1) and elevated (700 μmol·mol–1) CO2 in a glasshouse experiment. In both species, root/shoot ratios and fine root percentages (of total biomass) were u...

Global production of rice (Oryza sativa) grain is limited by water availability and the low 'leaf-level' photosynthetic capacity of many cultivars. Oryza sativa is extremely susceptible to water-deficits; therefore, predicted increases in the frequency and duration of drought events, combined with future rises in global temperatures and food demand, necessitate the development of more productiv...

To decrease adverse effects of water deficit is foliar application with chemical agents such as silicon. However, there is low information on the influence of silicon on alfalfa under drought stress conditions. Thus, the current study was conducted to assessment the effect of different silicon concentrations (0, 1 and 2 mili Molar concentration) on alfalfa growth trend and biochemical traits, w...

We developed a new method using 13CO2 and mass spectrometry to elucidate the role of photorespiration as an alternative electron dissipating pathway under drought stress. This was achieved by experimentally distinguishing between the CO2 fluxes into and out of the leaf. The method allows us to determine the rates of gross CO2 assimilation and gross CO2 evolution in addition to net CO2 uptake by...