Despite of the downward acclimation of photosynthesis in C. convoluta, increased net photosynthesis and carbon balance can be anticipated in response to elevated atmospheric C 0 2 level. C 0 2 exchange measurement seems to be more indicative when detecting heavy metal stress than fluorescence parameters. Among these, the relative fluorescence decrease ratio (RFd690) shows damage first, suggesti...

The senescence of excised discs of primary leaves of Phaseolus vulgaris, L., var. Red Kidney was followed by measuring the net breakdown of protein and chlorophyll. The chemical growth regulators indoleacetic acid, 2,4-dichlorophenoxy-acetic acid, gibberellic acid, kinetin, and 6-benzylaminopurine were relatively ineffective in retarding senescence in this tissue. White light, on the other hand...

Photosynthesis of green plants, algae and cyanobacteria is powered by sunlight. It uses water as ultimate donor of electrons for the reduction of CO2 to yield carbohydrates. Photosystem II (PS II), a water^ plastoquinone oxidoreductase, is the key enzyme of oxygenic photosynthesis. It is an integral protein of the thylakoid membrane. PS II is functionally bipartite, its photosynthetic reaction ...

A process-based, general ecosystem model (BIOME-BGC) was used to simulate daily gross primary production, maintenance and heterotrophic respiration, net primary production and net ecosystem carbon exchange of boreal aspen, jack pine and black spruce stands. Model simulations of daily net carbon exchange of the ecosystem (NEE) explained 51.7% (SE = 1.32 g C m(-2) day(-1)) of the variance in dail...

The atmospheric concentration of CO2 will probably rise to about 700 micromol mol(-1) by the end of this century. The effects of elevated growth CO2 on photosynthesis are still not fully understood. Effects of elevated growth CO2 on the capacity for photosynthesis of a single leaf and a whole plant were investigated with the radish cultivar White Cherish. The plants were grown under ambient ( a...

We describe a classification system for daily phytoplankton primary productivity models based on four implicit levels of mathematical integration. Depth-integrated productivity models have appeared in the literature on average once every 2 years over the past four decades. All of these models can be related to a single formulation equating depth-integrated primary production (2 PP) to surface p...

To determine the effects of ozone (O3) on the canopy carbon budget, we investigated photosynthesis and respiration of leaves of Siebold's beech saplings under free air O3 exposure (60 nmol mol(-1), during daytime) in relation to the within-canopy light gradient; we then calculated the canopy-level photosynthetic carbon gain (PCG) and respiratory carbon loss (RCL) using a canopy photosynthesis m...

We set up a free-air ozone (O(3)) exposure system for determining the photosynthetic responses of Siebold's beech (Fagus crenata) and oak (Quercus mongolica var. crispula) to O(3) under field conditions. Ten-year-old saplings of beech and oak were exposed to an elevated O(3) concentration (60 nmol mol(-1)) during daytime from 6 August to 11 November 2011. Ozone significantly reduced the net pho...

to better understanding of drought resistance features including tolerance to chemical desiccation and transient photosynthesis under soil moisture stress in triticale in comparison with wheat and barley, an experiment was conducted during year 2009-10 in grizeh agricultural research station located in sanandaj. effect of three soil moisture regimes including irrigation in soil water potential ...

Photoperiod and nutrient nitrogen (N) supply influence the growth, development, and productivity of crops. This study examined the physiological, biochemical, and morpho-anatomical traits of NA5 and NA9, two barley cultivars with contrasting photoperiod lengths, under the combined treatment of photoperiod regime and N supply. Under long photoperiod, high N supply decreased net photosynthesis; d...