Growing human population adds to the natural nitrogen loads to coastal waters. Both anthropogenic and natural nitrogen is readily incorporated in new biomass, and these different nitrogen sources may be traced by the measurement of the ratio of stable nitrogen isotopes (δ(15)N). In this study δ(15)N was determined in two species of macroalgae (Ascophyllum nodosum and Fucus vesiculosus), and in ...

Question: How are the effects of mineral soil properties on understory plant species richness propagated through a network of processes involving the forest overstory, soil organic matter, soil nitrogen, and understory plant abundance? Location: North-central Arizona, USA. Methods: We sampled 75 0.05-ha plots across a broad soil gradient in a Pinus ponderosa (ponderosa pine) forest ecosystem. W...

Species-rich grasslands that become enriched with nitrogen often suffer decreases in species richness, increases in plant biomass, and invasion by weedy exotic species. Suitable techniques to restore enriched grasslands and reestablish native communities are increasingly needed. Here we report results of a 5-yr experiment in enriched coastal prairie grasslands (Bodega Marine Reserve, Bodega Bay...

BACKGROUND AND AIMS Functional trait differences and trait adjustment in response to influences of the biotic environment could reflect niche partitioning among species. In this study, we tested how variation in above-ground plant traits, chosen as indicators for light and nitrogen acquisition and use, differs among taxonomically closely related species (Poaceae) to assess their potential for n...

Anthropogenic activities have severely altered fluxes of nitrogen and phosphorus in ecosystems worldwide. In grasslands, subsequent negative effects are commonly attributed to competitive exclusion of plant species following increased above-ground biomass production. However, some studies have shown that this does not fully account for nutrient enrichment effects, questioning whether lowering c...

Title of Document: A COMPETITIVE INTERACTION AND DOMINANCE EXPERIMENT BETWEEN THE VEGETATIVE MARSH SPECIES PHRAGMITES AUSTRALIS AND SPARTINA CYNOSUROIDES UNDER ELEVATED NITROGEN AND SALINITY LEVELS Michelle L. Arthur, Master of Science, 2013 Directed By: Dr. Andrew Baldwin, Department of Environmental Science and Technology In recent decades the invasive plant Phragmites australis (common reed)...

Oxidative stress is defined as the imbalance between reactive species such as free radicals and oxidants and the antioxidant defenses. Free radicals are molecules with one or more unpaired electrons, while oxidants are molecules with a high potential for taking electrons from other molecules. The more recognized reactive species are the reactive oxygen species (ROS), which include oxygen and it...

Photosynthetic capacity is one of the most sensitive parameters in vegetation models and its relationship to leaf nitrogen content links the carbon and nitrogen cycles. Process understanding for reliably predicting photosynthetic capacity is still missing. To advance this understanding we have tested across C(3) plant species the coordination hypothesis, which assumes nitrogen allocation to pho...

plant litter is an important factor for soil conservation and sustainability that could modify soil chemical properties and increase the plant biomass production. the aim of this research was to compare plant litter chemical composition and its effects on soil properties in three species including hordeum bulbosum, poa bulbosa, bromus tectorum. first, soil samples were taken in the depth of 0-3...

Reactive oxygen species, such as superoxide, and nitrogen oxides, such as peroxynitrite, are thought to contribute to beta-cell destruction during the disease process that leads to type 1 diabetes. EUK-8 is a member of a new class of synthetic salen-manganese compounds with low toxicity that possess catalytic superoxide dismutase, peroxidase, and catalase activity that can inactivate superoxide...