Plant Traits and Resource Reduction For Five Grasses Growing on a Nitrogen Gradient

摘要: Five grass species (Agrostis scabra, Agropyron repens, Poa pratensis, Schiz- achyrium scoparium and Andropogon gerardi) were grown in monoculture for 3 yr on an experimental nitrogen gradient. The differed significantly the levels to which they reduced soil solution (0.01 mol/L KCl extractable) nitrate ammonium concentrations light penetration surface. Soil concentration was inverse function of root mass, explained 73% observed variance nitrate. Other differences additional 9.2%, total N 5% this variance. Extractable also depended these variables, but most Light surface monocultures a negative exponential aboveground biomass (R2 = 0.79). Schizachyrium Andropogon, that lowest infertile soils, had lower vegetative growth rates, higher allocation, reproductive tissue than other species. Many traits are associated with plants habitats, suggesting direct link between ecophysiology, resource reduction, distributional patterns. Because all survived even our nitrogen-poor (subsurface sand), differential nutrient not tolerance, may be main mechanism favoring habitats. On three earlier successional (Agrostis, Agropyron, Poa) allocated more reproduction (rhizome or seed) later species, did reduce as low levels. This suggests early superior colonists inferior competitors compared prairie bunchgrasses. Our results can used make explicit predictions outcome competition among possible combinations five