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Biodiversity and Conservation

, Volume 16, Issue 7, pp 2045–2074 | Cite as

Rarity and abundance in a diverse African forest

  • David Kenfack
  • Duncan W. Thomas
  • George Chuyong
  • Richard Condit
Original Paper

Abstract

We censused all trees ≥1 cm dbh in 50 ha of forest in Korup National Park, southwest Cameroon, in the central African coastal forest known for high diversity and endemism. The plot included 329,519 individuals and 493 species, but 128 of those taxa remain partially identified. Abundance varied over four orders of magnitude, from 1 individual per 50 ha (34 species) to Phyllobotryon spathulatum, with 26,741 trees; basal area varied over six orders of magnitude. Abundance patterns, both the percentage of rare species and the dominance of abundant species were similar to those from 50-ha plots censused the same way in Asia and Latin America. Rare species in the Korup plot were much less likely to be identified than common species: 42% of taxa with <10 individuals in the plot were identified to species, compared to 95% of the abundant taxa. Geographic ranges for all identified species were gleaned from the literature and online flora. Thirteen of the plot species are known only from Korup National Park (all discovered during the plot census), and 39 are restricted to the Nigeria–Cameroon coastal zone. Contrary to expectation, species with narrow geographic ranges were more abundant in the plot than average. The small number of narrow endemics (11% of the species), many locally abundant, mitigates short-term extinction risk, either from demographic stochasticity or habitat loss.

Keywords

Korup Cameroon Tree abundance Dominance Rarity Geographic range 

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Notes

Acknowledgments

Funding for the fieldwork in Cameroon was provided by the International Cooperative Biodiversity Groups (a consortium of the U.S. National Institutes of Health, the U.S. National Science Foundation, and the U.S. Department of Agriculture), with supplemental funding by the Central Africa Regional Program for the Environment (a program of the U.S. Agency for International Development), and the Celerity Foundation at the Peninsula Community Foundation. Permission to conduct the field program in Cameroon was provided by the Ministry of Environment and Forests and the Ministry of Scientific and Technical Research. Data analyses were supported by U.S. National Science Foundation grant #009011 to the Center for Tropical Forest Science of the Smithsonian Tropical Research Institute, a global network of large-scale demographic plots.

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Copyright information

© Springer Science+Business Media B.V. 2006

Authors and Affiliations

  • David Kenfack
    • 1
  • Duncan W. Thomas
    • 2
  • George Chuyong
    • 3
  • Richard Condit
    • 4
    • 5
  1. 1.Missouri Botanical GardenLouisUSA
  2. 2.Department of Forest ScienceOregon State UniversityCorvallisUSA
  3. 3.Department of Life SciencesUniversity of BueaBueaCameroon
  4. 4.National Center for Ecological Analysis and SynthesisSanta BarbaraUSA
  5. 5.Smithsonian Tropical Research InstituteAPO AAUSA

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