The effect of leaf water deficit on net CO(2) assimilation was studied under two conditions: in one, the stomata were allowed to contribute to the regulation of CO(2) assimilation; in the other, air was forced through the leaf at a constant rate to overcome the effects of change in stomatal resistance accompanying changes in leaf water deficit. When the stomata were allowed to regulate the gase...

Since CO2 is the fundamental substrate for photosynthesis, fluctuating concentrations have a direct effect on plant growth and metabolism. Accordingly, enrichment within certain range was found to improve yields quality of plants. In order further understand underlying impact enrichment, this study employed an open-top chamber box model with following two treatments: control treatment (CO2 conc...

BACKGROUND Effects of elevated atmospheric CO2 concentrations on plant growth and associated C cycling have intensively been studied, but less is known about effects on the fluxes of radiatively active trace gases other than CO2. Net soil-atmosphere CH4 fluxes are determined by the balance of soil microbially-driven methane (CH4) oxidation and methanogenesis, and both might change under elevate...

Transpiration from plant canopies is an important determinant of surface energy budgets at the vegetated land surface. A recent parameterization of plant transpiration and stomatal conductance (Sellers et al., 1992a) is based on enzyme kinetics in plant chloroplasts. This paper presents background concepts in plant physiology and biochemistry needed to understand and evaluate the parameterizati...

dry matter production in oak (Quercus robur L.) seedlings and clonal cherry (Prunus avium L. × pseudocerasus Lind.) plants were measured during 19 months of growth in climate-controlled greenhouses at ambient (350 vpm) or elevated (700 vpm) CO2. In both species, the elevated CO2 treatment increased the PPFD saturated-rate of photosynthesis and dry matter production. After two months at elevated...

The ecosystem-level carbon uptake and respiration were measured under di€erent CO2 concentrations in the tropical rainforest and the coastal desert of Biosphere 2, a large enclosed facility. When the mesocosms were sealed and subjected to step-wise changes in atmospheric CO2 between daily means of 450 and 900 lmol mol, net ecosystem exchange (NEE) of CO2 was derived using the diurnal changes in...