SREL Reprint #1769
Competition between native and immigrant Polygonum congeners
B. Collins and G.R. Wein
Edward J. Meeman Biological Station and Department of Biology, Memphis State University, Memphis, TN 38152, USA
Abstract: Coexistence of annual herbs Polygonum punctatum, a native, and Polygonum caelpitosum, an immigrant, may result from (i) niche differentiation that reduces or avoids competition, (ii) competitive equivalence for shared resources, or (iii) interaction between a strong competitor and a species that tolerates competition. We investigated competitive interactions between the Polygonum congeners in a greenhouse experiment using plants grown from seed to seed set. Thinning profiles of monocultures were density dependent but did not differ between the species in monocultures. Biomass allocation to root, shoot, and racemes was not influenced by competition from conspecifics or congeners. Mature plant height and raceme production of both species were negatively affected by congener density; however, the species were not competitively equivalent. Polygonum caespitosum was suppressed into the shorter heights in mixture pots but produced more racemes at all but the greatest congener densities.
Keywords: competition, coexistence, annual herbs, immigrant
SREL Reprint #1769
Collins, B. and G. R. Wein. 1993. Competition between native and immigrant Polygonum congeners. Canadian Journal of Botany 71: 939-945.
This information was provided by the University of Georgia's Savannah River Ecology Laboratory (srel.uga.edu).