Biodiv Sci ›› 2020, Vol. 28 ›› Issue (10): 1182-1191.DOI: 10.17520/biods.2020035

• Original Papers • Previous Articles     Next Articles

The influence of harmful plant Wedelia biflora expansion on terrestrial mollusks in Xisha Islands

Biyue Yan1,3,4, Fuchun Tong2, Luhui Kuang1,3,4, Zhijian Mou1,3,4, Wenjia Wu1,3, Hongyue Cai1,4, Jun Wang1, Shuguang Jian1, Hai Ren1, Zhanfeng Liu1,3,*()   

  1. 1 Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems / CAS Engineering Laboratory for Vegetation Ecosystem Restoration on Islands and Coastal Zones, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650
    2 College of Forestry and Landscape Architecture, South China Agricultural University, Guangzhou 510642
    3 Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458
    4 University of Chinese Academy of Sciences, Beijing 100049
  • Received:2020-02-04 Accepted:2020-04-27 Online:2020-10-20 Published:2020-10-20
  • Contact: Zhanfeng Liu

Abstract:

It is well-documented that the expansion of Wedelia biflora profoundly impacts the structure and functions of the native plant community in the Xisha Islands, but the effects of this expansion on terrestrial mollusks remain unclear. In this study, we investigated the population density and shell features (e.g. height, width and mass) of the major groups of terrestrial mollusks: Achatina fulica, Subulinidae, Camaenidae and Ariphantidae. Mollusk conditions were assessed under different degrees of W. biflora expansion on Yongxing Island. Results showed: (1) As the coverage of W. biflora increased, the population density of A. fulica and Subulinidae also increased, decreased for Camaenidae, and initially increased and then decreased for Ariphantidae. (2) Population density of A. fulica small-sized individuals increased at a disproportionately higher rate with W. biflora expansion, while the density of other body size remained unaltered. (3) W. biflora expansion inhibited certain shell features of A. fulica, which adopted an r strategy to cope with W. biflora expansion. In summary, the expansion of W. biflora on Yingxing Island altered the body sizes, population density and community structure of terrestrial mollusks. To cope with this expansion, different mollusks adopted different response strategies, a selective process which should be considered when managing the spread of invasive species.

Key words: harmful plant, population expansion, Achatina fulica, inter species interaction, tropical coral island