In order to investigate the relative impacts of increases in day and night temperature on tree carbon relations, we measured night-time respiration and daytime photosynthesis of leaves in canopies of 4-m-tall cottonwood ( Populus deltoides Bartr. ex Marsh) trees experiencing three daytime temperatures (25, 28 or 31 ∞ C) and either (i) a constant nocturnal temperature of 20 ∞ C or (ii) increasin...

Plant growth and survival near range limits are likely sensitive to small changes in environmental conditions. Warming temperatures are causing range shifts and thus changes in species composition within range-edge ecotones; however, it is often not clear how temperature alters performance. Through an observational field study, we assessed temperature and nitrogen effects on survival and growth...

wheat, cv. alvand, under late sowing condition and comparison with conventional sowing date was investigated in a field experiment in 2009-2010. the factors were seven levels of priming by sa, including control or untreated seeds, 400, 800, 1200, 1600, 2000 and 2400 µm sa and two sowing dates including conventional sowing date (23 october) and late sowing (22 november). results showed that prim...

Efficient processing, handling, and storage of corn stover, a major crop‐based biomass, require an understanding of the moisture sorption thermodynamic properties of its fractions. Moisture sorption thermodynamic properties of the major corn stover fractions such as leaf, stalk skin, and stalk pith were determined, utilizing the static gravimetric sorption isotherms data in the temperature rang...

Biochemical leaf photosynthesis models are evaluated by laboratory results andhave been widely used at field scale for quantification of plant production,biochemical cycles and land surface processes. It is a key issue to search forappropriate model structure and parameterization, which determine modeluncertainty. A leaf photosynthesis model that couples the Farquhar-vonCaemmerer-Berry (FvCB) f...

in order to evaluate the effect of freezing stress on electrolyte leakage of three mooseers’ (allium altissimum regel.) ecotypes (shirvan, kalat and tandoureh), a factorial experiment based on completely randomized design with three replications was carried out under the controlled conditions in the faculty of agricultural, ferdowsi university of mashhad, iran, during 2009. plants were grown in...

Decreasing temperature and increasing precipitation along altitude gradients are typical mountain climate in subtropical China. In such a climate regime, identifying the patterns of the C stable isotope composition (δ(13)C) in plants and soils and their relations to the context of climate change is essential. In this study, the patterns of δ(13)C variation were investigated for tree leaves, lit...

Extensive research shows temperature to be the primary environmental factor controlling the phyllochron, or rate of leaf appearance, of wheat (Triticum aestivum L.). Experimental results suggest that soil temperature at crown depth, rather than air temperature above the canopy, would better predict wheat leaf appearance rates. To test this hypothesis, leaf appearance in spring wheat ('Nordic') ...

The temperature dependence of C3 photosynthesis is known to vary according to the growth environment. Atmospheric CO2 concentration and temperature are predicted to increase with climate change. To test whether long-term growth in elevated CO2 and temperature modifies photosynthesis temperature response, wheat (Triticum aestivum L.) was grown in ambient CO2 (370 micromol mol(-1)) and elevated C...

PREMISE OF STUDY Leaf shape is predicted to have important ecophysiological consequences; for example, theory predicts that lobed leaves should track air temperature more closely than their entire-margined counterparts. Hence, leaf-lobing may be advantageous during cold nights (∼0°C) when there is the risk of damage by radiation frost (a phenomenon whereby leaves fall below air temperature beca...