title: An invasive clonal plant benefits from clonal integration more than a co-occurring native plant in nutrient-patchy and competitive environments.
abstract: Many notorious invasive plants are clonal, however, little is known about the different roles of clonal integration effects between invasive and native plants. Here, we hypothesize that clonal integration affect growth, photosynthetic performance, biomass allocation and thus competitive ability of invasive and native clonal plants, and invasive clonal plants benefit from clonal integration more than co-occurring native plants in heterogeneous habitats. To test these hypotheses, two stoloniferous clonal plants, Alternanthera philoxeroides (invasive), Jussiaea repens (native) were studied in China. The apical parts of both species were grown either with or without neighboring vegetation and the basal parts without competitors were in nutrient- rich or -poor habitats, with stolon connections were either severed or kept intact. Competition significantly reduced growth and photosynthetic performance of the apical ramets in both species, but not the biomass of neighboring vegetation. Without competition, clonal integration greatly improved the growth and photosynthetic performance of both species, especially when the basal parts were in nutrient-rich habitats. When grown with neighboring vegetation, growth of J. repens and photosynthetic performance of both species were significantly enhanced by clonal integration with the basal parts in both nutrient-rich and -poor habitats, while growth and relative neighbor effect (RNE) of A. philoxeroides were greatly improved by clonal integration only when the basal parts were in nutrient-rich habitats. Moreover, clonal integration increased A. philoxeroides's biomass allocation to roots without competition, but decreased it with competition, especially when the basal ramets were in nutrient-rich sections. Effects of clonal integration on biomass allocation of J. repens was similar to that of A. philoxeroides but with less significance. These results supported our hypothesis that invasive clonal plants A. philoxeroides benefits from clonal integration more than co-occurring native J. repens, suggesting that the invasiveness of A. philoxeroides may be closely related to clonal integration in heterogeneous environments.
authors.affiliation: The National Field Station of Lake Ecosystem of Liangzi Lake, College of Life Science, Wuhan University, Wuhan, P.R. China.
authors.forename: Wenhua
authors.initials: W
authors.lastname: You
authors.affiliation: The National Field Station of Lake Ecosystem of Liangzi Lake, College of Life Science, Wuhan University, Wuhan, P.R. China.
authors.forename: Shufeng
authors.initials: S
authors.lastname: Fan
authors.affiliation: The National Field Station of Lake Ecosystem of Liangzi Lake, College of Life Science, Wuhan University, Wuhan, P.R. China.
authors.forename: Dan
authors.initials: D
authors.lastname: Yu
authors.affiliation: The National Field Station of Lake Ecosystem of Liangzi Lake, College of Life Science, Wuhan University, Wuhan, P.R. China.
authors.forename: Dong
authors.initials: D
authors.lastname: Xie
authors.affiliation: The National Field Station of Lake Ecosystem of Liangzi Lake, College of Life Science, Wuhan University, Wuhan, P.R. China.
authors.forename: Chunhua
authors.initials: C
authors.lastname: Liu
mesh_terms: D027703:Amaranthaceae / Q000254:growth & development*; D000704:Analysis of Variance; D018533:Biomass; D002681:China; D017753:Ecosystem; D058865:Introduced Species; D029594:Onagraceae / Q000254:growth & development*; D010788:Photosynthesis / Q000502:physiology; D012100:Reproduction, Asexual / Q000502:physiology*; D013045:Species Specificity