Although there is now some agreement with the view that the supply of photochemical energy may influence photosynthetic rate (P) at high CO2 pressures, it is less clear whether this limitation extends to P at low CO2. This was investigated by measuring P per area as a function of the intercellular CO2 concentration (C,) at different levels of photochemical energy supply. Changes in the latter w...

concentration of co2 in the atmosphere is likely to increase up to 550 µmol mol-1 by the middle of 21st century. such an increase in the atmospheric co2 would affect plant growth, and as well the productivity of crop plants. a field experiment was conducted with two potato cultivars namely kufri surya and kufri chipsona-3 grown inside open top chambers (otcs) at ambient (385±30 µmol mol-1) vs. ...

and growth of Mangifera indica L. saplings during long-term exposure to a CO2-enriched atmosphere in the seasonally wet-dry tropics of northern Australia. Grafted saplings of M. indica were planted in the ground in four air-conditioned, sunlit, plastic-covered chambers and exposed to CO2 at the ambient or an elevated (700 μmol mol) concentration for 28 months. Light-saturating assimilation (Ama...

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 ...