In many ecosystem models based on empirical formulations, parameters generally are calibrated in order to achieve the best fit between measured and simulated chlorophyll a standing stocks. An accurate calibration of rate processes as primary production rarely is taken into account. In this paper, we test the usefulness of calibration of phytoplankton photosynthetic processes in an ecosystem mod...

Ebria tripartita (Schumann) Lemmermann, 1899, a non-photosynthetic flagellate was identified from the southern coast of the Caspian Sea in December 2012. Water temperature at the sampling time was 10 ºC.  The abundance of total phytoplankton cells was 3 × 106 Cells.l-1, while E. tripartita with 2 × 10 3 Cells. l-1 included 0.75% of phytoplankton community. Water quality parameters were recorded...

Chlorophyll fluorescence has been routinely used for many years to monitor the photosynthetic performance of plants non-invasively. The relationships between chlorophyll fluorescence parameters and leaf photosynthetic performance are reviewed in the context of applications of fluorescence measurements to screening programmes which seek to identify improved plant performance. The potential role ...

Artificially implementing the biological light reactions responsible for the remarkably efficient photon-to-charge conversion in photosynthetic complexes represents a new direction for the future development of photovoltaic devices. Here, we develop such a paradigm and present a model photocell based on the nanoscale architecture and molecular elements of photosynthetic reaction centers. Quantu...

Rangelands play a critical role in the global carbon cycle. However, the eco-physiological mechanisms associated with the effects of grazing on leaf photosynthesis and soil respiration remain poorly understood. To examine the impacts of grazing on leaf photosynthesis and soil respiration, we measured the photosynthetic parameters of the dominant species (Trifolium repens) and the soil respirati...

Bistable optical emission has been observed for photosynthetic purple non-sulfur bacteria Rhodobacter capsulatus SB1003. The microbes respond to UV excitation (at 395nm) in a bifurcating way one branch corresponding to increase and the other corresponding to diminishing fluorescent emission in the range 590-685nm.The switching between such bifurcating branches can be observed when parameters li...

Comparison of the growth parameters and photosynthetic capacities of cells of Aphanocapsa 6714 under various growth conditions led to the following conclusions: (a), no enzymic regulation of CO(2)/glucose assimilation takes place in this strain; (b), functioning of photodependent phosphorylating pathways turns off oxidative ATP synthesis; (c), no efficient regulation of pigment synthesis exists...

Cadmium, a non-essential and toxic metal, negatively affects plant growth and productivity, and alters the plant's physiological processes necessary for its survival. The present study was designed to explore the individual and combined effects of calcium and salicylic acid (SA) on the morphology and physiology of Brassica juncea L. cv. Varuna under cadmium stress. The application of calcium (2...

Arundo donax has attracted interest as a potential bioenergy crop due to a high apparent productivity. It uses C3 photosynthesis yet appears competitive with C4 grass biomass feedstock's and grows in warm conditions where C4 species might be expected to be that productive. Despite this there has been no systematic study of leaf photosynthetic properties. This study determines photosynthetic and...

A plantation trial of six selected clones of Dalbergia sissoo Roxb. laid out in randomized block design at four sites in northern India during July, 1996 was evaluated for growth, physiological and biochemical parameters. Genotype-site interactions were significant for collar diameter increment, photosynthetic rate, transpiration rate, stomatal conductance, photosynthetic pigments, total solubl...