Filters: Tags: photosynthesis (X)520 results (135ms)
Photosynthetic performance at low temperature of Bouteloua gracilis Lag., a highâ€�altitude C4 grass from the Rocky Mountains, USA
The mechanisms controlling the photosynthetic performance of C4 plants at low temperature were investigated using ecotypes of Bouteloua gracilis Lag. from high (3000 m) and low (1500 m) elevation sites in the Rocky Mountains of Colorado. Plants were grown in controlled-environment cabinets at a photon flux density of 700 Î¼mol mâˆ’2 sâˆ’1 and day/night temperatures of 26/16 Â°C or 14/7 Â°C. The thermal response of the net CO2 assimilation rate (A) was evaluated using leaf gas-exchange analysis and activity assays of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), phosphoenolpyruvate carboxylase (PEPCase) and pyruvate,orthophosphate dikinase (PPDK). In both ecotypes, a reduction in measurement temperature...
Leaf gas exchange and water status responses of a native and non-native grass to precipitation across contrasting soil surfaces in the Sonoran Desert.
Arid and semi-arid ecosystems of the southwestern US are undergoing changes in vegetation composition and are predicted to experience shifts in climate. To understand implications of these current and predicted changes, we conducted a precipitation manipulation experiment on the Santa Rita Experimental Range in southeastern Arizona. The objectives of our study were to determine how soil surface and seasonal timing of rainfall events mediate the dynamics of leaf-level photosynthesis and plant water status of a native and non-native grass species in response to precipitation pulse events. We followed a simulated precipitation event (pulse) that occurred prior to the onset of the North American monsoon (in June) and...
Gas exchange and water relations of two Rocky Mountain shrub species exposed to a climate change manipulation
Gas exchange and water relations responses to warming were compared for two shrub species, Artemisia tridentata spp. vaseyana (Asteraceae), a widely distributed evergreen species of the Great Basin and the western slope of the Rocky Mountains, and Pentaphylloides floribunda (Rosaceae), a deciduous shrub limited in distribution to moist, high-elevation meadows. Plants were exposed to an in situ infrared (IR) climate change manipulation at the Rocky Mountain Biological Laboratory, near Crested Butte, CO. Measurements of gas exchange and water relations were made on the two species in July and August, 1993 from plants growing in situ in infrared-heated and control plots. Carbon dioxide uptake, water loss, leaf temperature,...
Isolation and characterization of a mildly thermophilic nonsulfur purple bacterium containing bacteriochlorophyll b.
Effect of water and nitrogen amendments on photosynthesis, leaf demography, and resource-use efficiency in Larrea tridentata , a desert evergreen shrub.
Autumnal leaf conductance and apparent photosynthesis by saplings and sprouts in a recently disturbed northern hardwood forest.
Net photosynthesis as a function of carbon dioxide concentration in pine trees grown at ambient and elevated CO sub(2)
Cytochrome f loss in astaxanthin-accumulating red cells of Haematococcus pluvialis (Chlorophyceae): Comparison of photosynthetic activity, photosynthetic enzymes, and thylakoid membrane polypeptides in red and green cells
Phytoplankton productivity in Saginaw Bay, Lake Huron: Effects of zebra mussel (Dreissena polymorpha) colonization
Combination effects of UV-B radiation and temperature on sunflower (Helianthus annuus L., cv. Polstar) and maize (Zea mays L., cv. Zenit 2000) seedlings
Role of the Sahelian biosphere on the water and the CO sub(2) cycle during the HAPEX-Sahel experiment
Modelling the daily integral of photosynthesis by phytoplankton: Its dependence on the mean depth of the population
Combined effects of light and water availability on photosynthesis and growth of Arisaema heterophyllum in the forest understory and an open site
Estimation of the annual primary production of stream epilithic biofilms based on photosynthesis-irradiance relations