Biodiv Sci

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Community characteristics and interspecific association of the Songyang population of Isoetes sinensis

Shengchao Zhu*   

  1. Department of Biology, Lishui University, Lishui, Zhejiang 323000
  • Received:2006-01-16 Revised:2006-03-27 Online:2006-05-20 Published:2006-05-20
  • Contact: Shengchao Zhu

Abstract:

Isoetes sinensis (Isoeteaceae), a critically endangered species in China, has declined rapidly in population size in recent years. Interspecific associations, which play an important role in ecosystem functioning, can reflect interspecific competition within communities. We investigated the habitat characteristics of the I. sinensis population in Songyang of Zhejiang Province using 1 m×1 m quadrats. Based on 2×2 contingency tables using test and association coefficients (AC), we analyzed the interspecific associations of I. sinensis with 27 common species frequently appearing in the community. The results showed that species abundance of the community was poor and the community was dominated by temperate elements. Isoetes sinensis can form the dominant population in a few microcoenses, but its density varied remarkably in different community types. The 2 values implied that I. sinensis had close relationship with seven species such as Neanotis hirsuta, Eclipta prostrata and Carex brevicuspis, but had no correlations with most species, with association coefficients (AC) ranging from –0.4 to 0.4. With poor ecological adaptability, I. sinensis is greatly affected by habitat and interspecific competition in the community. This result can provide information for design of an appropriate conservation strategy and restoration plan for I. sinensis.