title: Intraspecific competition, growth, chemistry, and susceptibility to voles in seedlings of Betula pendula.
abstract: We studied the effects of the intensity of intraspecific competition, as indicated by seedling density, and competitive success within populations, as indicated by seedling size, on the secondary chemistry of the stems of silver birch seedlings and their palatability to field voles. We found that the size of seedlings and their total phenolic concentrations were inversely related to stand density. Voles, however, did not discriminate between seedlings grown at the densities studied. Variation in competitive success was associated with several phenomena. Seedling size was positively related to the concentrations of several secondary compounds and to vole preferences, but negatively related to nitrogen concentration. We suggest that the ecological consequences of variation in seedling size cannot be predicted without knowledge of the mechanism behind the variation.
authors.affiliation: Department of Biology, University of Joensuu, P.O. Box 111, FIN-80101, Joensuu, Finland. mtiainen@cc.joensuu.fi
authors.forename: Merja
authors.initials: M
authors.lastname: Tiainen
authors.forename: Jyrki
authors.initials: J
authors.lastname: Pusenius
authors.forename: Riitta
authors.initials: R
authors.lastname: Julkunen-Tiitto
authors.forename: Heikki
authors.initials: H
authors.lastname: Roininen
mesh_terms: D000818:Animals; D003411:Arvicolinae / Q000502:physiology*; D029662:Betula / Q000737:chemistry* / Q000254:growth & development*; D018533:Biomass; D002851:Chromatography, High Pressure Liquid; D005419:Flavonoids / Q000032:analysis; D005518:Food Preferences / Q000502:physiology*; D009584:Nitrogen / Q000032:analysis; D009929:Organ Size; D010636:Phenols / Q000032:analysis; D018517:Plant Roots / Q000033:anatomy & histology; D018547:Plant Stems / Q000033:anatomy & histology / Q000737:chemistry; D036226:Seedlings / Q000033:anatomy & histology / Q000737:chemistry* / Q000254:growth & development*; D013045:Species Specificity; D013997:Time Factors
chemical_list: D005419:Flavonoids; D010636:Phenols; D009584:Nitrogen