Leaf N concentration is important because it is associated with the CO2 assimilatory capacity of crops, and in grasslands, it is an important determinant of forage nutritive value. Consequently, the productivity of both domestic and native animals in future global environments may be closely linked to possible changes in leaf N concentration of grasses. Since grasslands are frequently subjected...

Using controlled environmental growth chambers, whole plants of soybean, cv. ‘Clark’, were examined during early development (7–20 days after sowing) at both ambient (μ 350 μL L–1) and elevated (μ 700 μL L–1) carbon dioxide and a range of air temperatures (20, 25, 30, and 35 °C) to determine if future climatic change (temperature or CO2 concentration) could alter the ratio of carbon lost by dar...

A simple CO2 control system was developed for a greenhouse with a high natural or forced ventilation rate. This CO2 control system maintains the difference in CO2 concentration between inside and outside the greenhouse, ∆C, during daytime being small (ca. 5 μmol mol), by supplying a variable amount of CO2 gas with time. Results showed that this system worked satisfactorily, while the CO2 concen...

The objective of this study was to determine if low stomatal conductance (g) increases growth, nitrate (NO3 (-)) assimilation, and nitrogen (N) utilization at elevated CO2 concentration. Four Arabidopsis (Arabidopsis thaliana) near isogenic lines (NILs) differing in g were grown at ambient and elevated CO2 concentration under low and high NO3 (-) supply as the sole source of N. Although g varie...

The use of analogies and repeated feedback might help people learn about the dynamics of climate change. In this paper, we study the influence of repeated feedback on the control of a carbon-dioxide (CO2) concentration to a goal level in a Dynamic Climate Change Simulator (DCCS) using the “bathtub” analogy. DCCS is a simplification of the complex climate system into its essential elements: CO2 ...

Forecasting the effects of climate change on nitrogen (N) cycling in pastures requires an understanding of changes in tissue N. We examined the effects of elevated atmospheric CO2 concentration, atmospheric warming and simulated grazing (clipping frequency) on aboveground and belowground tissue N concentrations and C : N ratios of a C3 pasture grass. Phalaris aquatica L. cv. 'Holdfast' was grow...

Global climate changes involve elevated temperature and CO2 concentration, imposing significant impact on plant growth of various plant species. Elevated temperature exacerbates heat damages, but elevated CO2 has positive effects on promoting plant growth and heat tolerance. The objective of this study was to identify metabolic pathways affected by elevated CO2 conferring the improvement of hea...

Model projections suggest that although increased temperature and decreased soil moisture will act to reduce global crop yields by 2050, the direct fertilization effect of rising carbon dioxide concentration ([CO2]) will offset these losses. The CO2 fertilization factors used in models to project future yields were derived from enclosure studies conducted approximately 20 years ago. Free-air co...