Great Plains Natural Science Society


The Prairie Naturalist

Date of this Version


Document Type



The Prairie Naturalist 43(1/2):45–51; 2011


Published by the Great Plains Natural Science Society. Used by permission.


We conducted an experiment to investigate effects of species, water (W), and nitrogen (N) on competition among little bluestem (Schizachyrium scoparium), sideoats grama (Bouteloua curtipendula), and indiangrass (Sorghastrum nutans). All biomass parameters and the root:shoot ratio of little bluestem were reduced by the presence off 1 of 2 other species, and its shoot biomass and total biomass were both increased by addition of N. Root and shoot biomass of sideoats grama were reduced by the presence of indiangrass and its total biomass was reduced by the presence of itself, whereas its shoot biomass was increased by addition of W at the highest level. Root biomass and total biomass of indiangrass were increased by N and that response pattern was preserved for root biomass but lost for total biomass when W was added. We conclude that grass seedlings were affected by species more than by levels of W and N, interspecific competition was more important than intraspecific competition, and both N and W effects occurred only in the highest levels of addition with some interaction.