title: No evidence for a role of competitive capabilities of adults in causing habitat segregation of diploid and hexaploidSenecio carniolicus(Asteracaeae).
abstract: Hexaploid individuals ofSenecio carniolicus(Asteraceae) predominantly occur in dense swards while diploids prevail in open vegetation. We test whether this habitat segregation is due to differential responses to competition. Linear regression models were used to relate biomass and maximum leaf length of adults to vegetation cover within radii of 20 cm around target individuals. Biomass differed between ploidy levels, but was independent from vegetation cover in both cytotypes. Maximum leaf length of diploids increased with vegetation cover, but remained constant in hexaploids. This suggests that at the adult stage diploids respond to increasing competition by changes in plant architecture rather than changes in resource utilization, while hexaploids are unaffected by competition. Consequently, other factors, such as competitive interactions at earlier life stages, likely are responsible for habitat segregation of diploid and hexaploidS. carniolicus.
authors.affiliation: Vienna Institute for Nature Conservation & Analyses, Giessergasse 6/7, 1090 Vienna, Austria; Department of Conservation Biology Vegetation and Landscape Ecology, University of Vienna, Rennweg 14, 1030 Vienna, Austria.
authors.forename: Karl
authors.initials: K
authors.lastname: Hülber
authors.affiliation: Department of Systematic and Evolutionary Botany, University of Vienna, Rennweg 14, 1030 Vienna, Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Berger
authors.affiliation: Department of Systematic and Evolutionary Botany, University of Vienna, Rennweg 14, 1030 Vienna, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Gilli
authors.affiliation: Department of Systematic and Evolutionary Botany, University of Vienna, Rennweg 14, 1030 Vienna, Austria.
authors.forename: Markus
authors.initials: M
authors.lastname: Hofbauer
authors.affiliation: Department of Conservation Biology Vegetation and Landscape Ecology, University of Vienna, Rennweg 14, 1030 Vienna, Austria.
authors.forename: Monika
authors.initials: M
authors.lastname: Patek
authors.affiliation: Department of Systematic and Evolutionary Botany, University of Vienna, Rennweg 14, 1030 Vienna, Austria.
authors.forename: Gerald M
authors.initials: GM
authors.lastname: Schneeweiss
keywords: Alpine plants; Biomass; Competition; Polyploidy; Vegetation cover