Understory red spruce (Picea rubens Sarg.) trees, between 20 and 50 cm in height and 12 years or more in age, were collected from mid- and high-elevation stands in north-central Vermont and placed in a closed-cuvette system to measure photosynthetic and transpirational responses to photosynthetic photon flux density (PPFD) and temperature. Photosynthesis, dark respiration, transpiration and wat...

terminal drought stress during grain filling period has recently become more common in the semiarid mediterranean regions, where wheat (triticum aestivum) is grown as an important winter cereal crop. the objective of this experiment was to study the effect of terminal drought stress on grain yield, gas exchange variables, and some physiological traits of nine bread wheat cultivars. an experimen...

It is important to develop a convenient method for predicting photosynthetic rates in cold regions such as high elevations. Dwarf pine Pinus pumila representative treeline species Japan. In this study, we investigated how environmental factors affect diurnal and seasonal variations of the situ rate P. pumila. Five (photosynthetic photon flux density [PPFD], air temperature [Ta], soil [Ts], vapo...

We explored the effect of high-growth temperatures on a dominant North American boreal tree, black spruce [Picea mariana (Mill.) B.S.P.]. In 2004 and 2005, we grew black spruce at either 22 1C/16 1C day/night temperatures [low temperature (LT)] or 301/24 1C [high temperature (HT)] and determined how temperature affected growth, leaf morphology, photosynthesis, respiration and thermotolerance. H...

Long-term excessive application of chemical fertilizers can cause many problems, such as soil degradation and environmental pollution. Therefore, we reduced conventional nitrogen fertilization added organic in some cases to investigate the response photosynthetic characteristics, root nodules yield on fertilization. Compared fertilization, 25% 35% reduction treatments leaf area index, net rate,...

Daily productivity determinations of linear photosynthetic electron transfer and of net and gross inorganic CO2 uptake were determined in situ throughout a 6-week sampling period of the spring phytoplankton bloom in Esthwaite Water in the English Lake District. Photosynthetic electron transfer rates, expressed as gross O2 evolution, were determined from fast repetition rate (FRR) fluorometry an...