Effects of nitrogen availability on the growth of native grasses exotic weeds.

摘要: Many studies have shown that high nitrogen availability encourages the community dominance of exotic, weedy species. Other researchers attempted to reduce existing exotic species infestations by reducing soil availability. We tested hypothesis weeds and native differ in their response availability, predicting exotics would a much more positive than natives at levels but better tolerate low levels. To test this hypothesis, we conducted greenhouse experiment investigating aboveground biomass, belowground height, tissue concentration 2 North American plant species, blue grama (Bouteloua gracilis H.B.K. Lag.) western wheatgrass (Pascopyrum smithii (Rybd.) A. Love), 4 cheatgrass (Bromus tectorum L.), leafy spurge (Euphorbia esula Canada thistle (Cirsium arvense Russian knapweed (Centaurea repens 5 0 g N/m2, 1 7g 10 N/m2. grew single individuals each from seed 3 liter pots for 75 days. The did not predicted manner. with poorest was an exotic. There were no differences between any level root:shoot ratios, total or percent leaf nitrogen, as group gained height every Our data do show generalizable relationship groups growth nitrogen. DOI:10.2458/azu_jrm_v55i1_lowe