Capacity for clonal integration in introduced versus native clones of the invasive plant Hydrocotyle vulgaris

Chao Si; Peter Alpert; Jian-Feng Zhang; Jing Lin; Yi-Yue Wang; Meng-Meng Hong; Sergio R Roiloa; Fei-Hai Yu

doi:10.1016/j.scitotenv.2020.141056

Capacity for clonal integration in introduced versus native clones of the invasive plant Hydrocotyle vulgaris

Sci Total Environ. 2020 Nov 25:745:141056. doi: 10.1016/j.scitotenv.2020.141056. Epub 2020 Jul 20.

Authors

Chao Si¹, Peter Alpert², Jian-Feng Zhang³, Jing Lin³, Yi-Yue Wang³, Meng-Meng Hong³, Sergio R Roiloa⁴, Fei-Hai Yu⁵

Affiliations

¹ Institute of Wetland Ecology & Clone Ecology/Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou 318000, China; School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China.
² Biology Department, University of Massachusetts, Amherst, MA 01003, USA.
³ Institute of Wetland Ecology & Clone Ecology/Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou 318000, China.
⁴ BioCost Group, Biology Department, Universidade da Coruña, A Coruña 15071, Spain.
⁵ Institute of Wetland Ecology & Clone Ecology/Zhejiang Provincial Key Laboratory of Plant Evolutionary Ecology and Conservation, Taizhou University, Taizhou 318000, China; School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, China. Electronic address: feihaiyu@126.com.

PMID: 32717606
DOI: 10.1016/j.scitotenv.2020.141056

Abstract

Clonal plants can make up a disproportionately high number of the introduced, invasive plant species in a region. Physiological integration of connected ramets within clones is a key ecological advantage of clonal growth. To ask whether clonal integration underlies the invasiveness of clonal plants, we tested the hypothesis that introduced clones of an invasive species will show higher capacity for integration than native clones of the same species. We conduct a greenhouse experiment on the widespread, perennial herb Hydrocotyle vulgaris. Clonal fragments consisting of pairs of connected ramets from seven sites in northwestern Spain where the species is native and seven sites in southeastern China where the species is introduced and invasive were grown for 79 days with the younger, apical ramet shaded to 30% of ambient light and the connection between ramets either severed or left intact. Severance decreased the final dry mass and ramet number of the apical ramet and its offspring in nearly all clones and increased the mass or ramet number of the basal portion of the fragment in about half of the clones, but these effects did not differ consistently between native and introduced clones. Severance did affect allocation more in introduced than in native clones, decreasing root/total mass more in apical portions and increasing it more in basal portions. Maintaining the connection between ramets caused introduced, but not native, clonal fragments to produce more leaf and less root mass and thus to lower allocation to roots. Regardless of severance, introduced clones accumulated about twice as much mass as native clones. Results suggest that introduced clones of a species can show greater effects of integration on allocation than native clones. In species such as H. vulgaris, this might increase competitiveness for light.

Keywords: Biomass allocation; Clonal integration; Genotype; Hydrocotyle vulgaris; Introduced invasive plant species.

MeSH terms

Araliaceae*
Biomass
Centella*
China
Introduced Species
Spain