Reproductive Strategies in Dewberries

Abstract

Two predictions are made. (1) In a stable, predictable habitat when population density is low and clonal expansion is possible, vegetative reproduction should be favored. When population density is high because of crowding, plants should put a greater proportion of their resources into seed reproduction, resulting in dispersal. (2) In a temporally unstable habitat, this reproductive density response will not exist. Field studies utilizing Rubus hispidus and Rubus trivalis confirm the first prediction but not the second. In addition, cattle grazing and precipitation had a marked effect on mode of reproduction.