Fixed or mixed? variation in tree functional types and vegetation structure in a forest-savanna ecotone in West Africa

  • George K.D. Ametsitsi (Kwame Nkrumah University of Science and Technology) (Creator)
  • Thomas Adjei-Gyapong (Creator)
  • Vincent Logah (Creator)
  • Jon Lloyd (Creator)
  • Elmar Veenendaal (Creator)



We analysed thirty-five 400-m2 plots encompassing forest, savanna and intermediate vegetation types in an ecotonal area in Ghana, West Africa. Across all plots, fire frequency was over a period of 15 years relatively uniform (once in 2–4 years). Although woodlands were dominated by species typically associated with savanna-type formations, and with forest formations dominated by species usually associated with closed canopies, these associations were non-obligatory and with a discrete non-specialized species grouping also identified. Across all plots, crown area index, stem basal area and above-ground biomass were positively associated with higher soil exchangeable potassium and silt contents: this supporting recent suggestions of interplays between potassium and soil water storage potential as a significant influence on tropical vegetation structure. We also found an average NDVI cover increase of ~0.15% year−1 (1984–2011) with plots dominated by non-specialized species increasing more than those dominated by either forest- or savanna-affiliated species. Our results challenge the traditional view of a simple forest vs. savanna dichotomy controlled by fire, and with our newly identified third non-specialized species grouping also potentially important in understanding ecotonal responses to climate change.,Refer to the uploaded file,
Date made available23 Jul 2020
PublisherWageningen University & Research

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