Impact of human foraging on tree diversity, composition, and abundance in a tropical rainforest

Sijeh A. Asuk*, Thomas J. Matthews, Jonathan P. Sadler, Thomas A.M. Pugh, Vincent T. Ebu, Nzube M. Ifebueme, Nicholas Kettridge

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

85 Downloads (Pure)


Tropical forest tree communities are structured by a range of large-scale drivers including elevation, certain high-impact anthropogenic activities (e.g., deforestation), and fires. However, low-impact human activities such as foraging may also be subtly but notably altering the composition of tropical forest tree communities. The study assessed the (i) differences in species diversity, patterns of relative abundance, and pairwise beta diversity between trees with edible and inedible fruits and seeds along an elevation gradient, and (ii) impact of human foraging on the forest tree communities in Oban Division of Cross River National Park, Nigeria. Fifteen permanent 40 by 40 m plots were established along an elevational gradient (120–460 m above mean sea level). All trees of 0.1 m diameter at breast height (dbh) and above were measured, identified, and, with the aid of structured questionnaires, classified into those with edible and inedible fruits/seeds. A total of 35 edible species with density of 128 stems/hectare and basal area of 11.99 m2/hectare, and 109 inedible species with density of 364 stems/hectare and basal area of 22.42 m2/hectare were sampled. However, the evenness of edible and inedible species was similar at pooled and plot levels. For inedible species, there was a positive relationship between pairwise beta diversity and elevation, and this was driven mainly by turnover. In contrast, edible species exhibited a non-significant trend between elevation and beta diversity. Thus, the study showed that human foraging of edible fruits may have subtly influenced patterns of species diversity and community structure in this tropical forest.

Original languageEnglish
Pages (from-to)1-14
Number of pages14
Issue number1
Early online date27 Nov 2022
Publication statusPublished - Jan 2023

Bibliographical note

Funding Information:
We gratefully acknowledge the following people: for data collections: Mr Albert; for logistical support and field research assistance: Birmingham Institute of Forest Research (BIFOR), Sagan Friant's Risk laboratory, and staff of Cross River National Park—Nigeria; for comments and suggestions: Adriane Esquivel Muelbert. Permission to established permanent sample plots and collect data was given by the Nigerian National Park Service. Funding was provided by the Petroleum Technology Development Fund (PTDF), Nigeria. This paper contributes towards the Strategic Research Areas BECC and MERGE.

Publisher Copyright:
© 2022 The Authors. Biotropica published by Wiley Periodicals LLC on behalf of Association for Tropical Biology and Conservation.


  • Africa
  • beta diversity
  • edible trees
  • evenness
  • human foraging
  • inedible trees
  • species abundance distribution
  • tropical rainforest

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics


Dive into the research topics of 'Impact of human foraging on tree diversity, composition, and abundance in a tropical rainforest'. Together they form a unique fingerprint.

Cite this