title: Invasive clonal plant species have a greater root-foraging plasticity than non-invasive ones.
abstract: Clonality is frequently positively correlated with plant invasiveness, but which aspects of clonality make some clonal species more invasive than others is not known. Due to their spreading growth form, clonal plants are likely to experience spatial heterogeneity in nutrient availability. Plasticity in allocation of biomass to clonal growth organs and roots may allow these plants to forage for high-nutrient patches. We investigated whether this foraging response is stronger in species that have become invasive than in species that have not. We used six confamilial pairs of native European clonal plant species differing in invasion success in the USA. We grew all species in large pots under homogeneous or heterogeneous nutrient conditions in a greenhouse, and compared their nutrient-foraging response and performance. Neither invasive nor non-invasive species showed significant foraging responses to heterogeneity in clonal growth organ biomass or in aboveground biomass of clonal offspring. Invasive species had, however, a greater positive foraging response in terms of root and belowground biomass than non-invasive species. Invasive species also produced more total biomass. Our results suggest that the ability for strong root foraging is among the characteristics promoting invasiveness in clonal plants.
authors.affiliation: Institute of Plant Sciences, University of Bern, Altenbergrain 21, 3013, Bern, Switzerland, lidewij.keser@gmail.com.
authors.forename: Lidewij H
authors.initials: LH
authors.lastname: Keser
authors.forename: Wayne
authors.initials: W
authors.lastname: Dawson
authors.forename: Yao-Bin
authors.initials: YB
authors.lastname: Song
authors.forename: Fei-Hai
authors.initials: FH
authors.lastname: Yu
authors.forename: Markus
authors.initials: M
authors.lastname: Fischer
authors.forename: Ming
authors.initials: M
authors.lastname: Dong
authors.forename: Mark
authors.initials: M
authors.lastname: van Kleunen
mesh_terms: D018533:Biomass; D002999:Clone Cells; D058865:Introduced Species; D019684:Magnoliopsida / Q000254:growth & development*; D018517:Plant Roots / Q000254:growth & development*; D012987:Soil; D014481:United States
chemical_list: D012987:Soil