Carbon dioxide (CO2) is a major climate forcing factor, closely related to human activities. Quantifying the contribution of CO2 emissions global radiative (RF) therefore important evaluate effects caused by anthropogenic and natural factors. China, United States (USA), Russia Canada are largest countries land area, at different levels socio-economic development. In this study, we used data fro...

The effect of 3,3-dichloro-2-(dihydroxyphosphinoylmethyl)propenoate (DCDP), an analog of phosphoenolpyruvate (PEP), on PEP carboxylase activity in crude leaf extracts and on photosynthesis of excised leaves was examined. DCDP is an effective inhibitor of PEP carboxylase from Zea mays or Pancum miliaceum; 50% inhibition was obtained at 70 or 350 micromolar, respectively, in the presence of I mil...

The O2 and CO2 compensation points (O2 and CO2) of plants in a closed system depend on the ratio of CO2 and O2 concentrations in air and in the chloroplast and the specificities of ribulose bisphosphate carboxylase/oxygenase (Rubisco). The photosynthetic O2 is defined as the atmospheric O2 level, with a given CO2 level and temperature, at which net O2 exchange is zero. In experiments with C3 pl...

Coffee is one of the world's most traded agricultural products. Modeling studies have predicted that climate change will have a strong impact on the suitability of current cultivation areas, but these studies have not anticipated possible mitigating effects of the elevated atmospheric [CO2] because no information exists for the coffee plant. Potted plants from two genotypes of Coffea arabica an...

Chloroplast-targeted overexpression of an Fe superoxide dismutase (SOD) from Arabidopsis thaliana resulted in substantially increased foliar SOD activities. Ascorbate peroxidase, glutathione reductase, and monodehydroascorbate reductase activities were similar in the leaves from all of the lines, but dehydroascorbate reductase activity was increased in the leaves of the FeSOD transformants rela...

Experiments are described further indicating that 02-resistant photosynthesis observed in a tobacco (Nicotiana tabacum) mutant with enhanced catalase activity is associated with decreased photorespiration under conditions of high photorespiration relative to net photosynthesis. The effects on net photosynthesis of (a) increasing O2 concentrations from 1% to 42% at low CO2 (250 microliters CO2 p...

We observed diurnal and seasonal patterns of leaf-scale gas exchange within the crown of a Dipterocarpus sublamellatus Foxw. tree growing in a lowland dipterocarp forest at Pasoh, Peninsular Malaysia. Observations were carried out nine times over 6 years, from September 2002 to December 2007. Observation periods included both wet and mild-dry periods, and natural and saturated photosynthetic ph...

Growth parameters such as leaf area (LA), total dry mass (TDM) production, crop growth rate (CGR), relative growth rate (RGR), and net assimilation rate (NAR) were compared in six varieties of mungbean under subtropical condition (24°8' N 90°0' E) to identify limiting growth characters for the efficient application of physiology breeding for higher yields. Results revealed that a relatively sma...

Disturbances such as fire, hurricanes, and herbivory often result in the net release of CO2 from forests to the atmosphere, but the magnitude of carbon (C) loss is poorly quantified and difficult to predict. Here, we investigate the carbon balance of an oak/pine forest in the New Jersey Pine Barrens using the Canopy Conductance Constrained Carbon Assimilation (4C-A) model. The 4C-A model utiliz...