Species composition, spatial heterogeneity, interspecific association and diversity of an early successional plant community: A comparison of some species association indices

Shaukat, S.S. . Inst. of Environmental Studies; Hussain, F. . Dept. of Agriculture and Agribusiness Management; Zafar, H. . Dept. of Botany; Rao, T.A. . Dept. of Botany; Mahmood, K. . Inst. of Environmental Studies; Raza, A. . Dept. of Environmental Science

Species composition, spatial heterogeneity, interspecific association and diversity of an early successional plant community: A comparison of some species association indices

Shaukat, S.S. (Karachi Univ. (Pakistan). Inst. of Environmental Studies) | Hussain, F. (Karachi Univ. (Pakistan). Dept. of Agriculture and Agribusiness Management) | Zafar, H. (Federal Urdu Univ. of Arts, Science and Technology, Karachi (Pakistan). Dept. of Botany) | Rao, T.A. (Federal Urdu Univ. of Arts, Science and Technology, Karachi (Pakistan). Dept. of Botany) | Mahmood, K. (Karachi Univ. (Pakistan). Inst. of Environmental Studies) | Raza, A. (Federal Urdu Univ. of Arts, Science and Technology, Karachi (Pakistan). Dept. of Environmental Science)

The investigation focuses on species composition, spatial heterogeneity, diversity and interspecific associations in an early successional plant community. A total of twenty species were recorded of which five were grasses while the rest were undershrubs or perennial herbs. Out of 11 species investigated for spatial pattern using variance/ mean ratio and Morisita's index, ten exhibited aggregated distribution pattern which was presumably caused by topographic-edaphic heterogeneity or by limited seed dispersal. Test for species richness pattern within the community showed variability in species richness which can be attributed to environmental heterogeneity. Species diversity (H´) was moderate (H´ = 2.442), equitability was also moderate (J´= 0.815) while species richness (d) was 0.575. Dominance-diversity curve approached geometric distribution. Dominance (D) was low. Ten different species association coefficients (or similarity indices) were tested and compared of which three including those proposed by Jaccard, Soenesen & Dice and Ochiai provided consistent results in terms of disclosing the degree of interspecific association. These three measures are recommended for application in ecology.

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