Agroforestry Systems

, Volume 82, Issue 1, pp 25–35 | Cite as

Folk perception of sexual dimorphism, sex ratio, and spatial repartition: implications for population dynamics of Sclerocarya birrea [(A. Rich) Hochst] populations in Benin, West Africa

  • Gerard Nounagnon Gouwakinnou
  • Anne Mette Lykke
  • Bruno Agossou Djossa
  • Brice Sinsin


In Sub-Saharan Africa, indigenous fruit trees play vital roles in nutrition and food security particularly, in food shortage times. Sclerocarya birrea subsp. birrea, an indigenous dioecious fruit tree is such a resource with strong multipurpose use characteristics in semi-arid zones of West Africa. We assessed sex ratio, spatial distribution among male and female adult trees using second-order spatial statistics and assessed folk perception of dioecism among the natural populations in protected areas and surrounding agroforestry systems. A field survey showed that 55% of interviewees were aware of sex separation in the species. Some used bark appearance to make distinction between sexes, but this morphological criterion was not consistent with statistical results. The sex ratio did not deviate significantly from 0.5 in any of the districts or land use types. Bivariate spatial analysis with pair correlation function revealed no spatial association between male and female individuals. Moreover, a strict spatial segregation of sexes was not observed even though some individuals of the same sex could sometimes be found together. Results confirmed the functional dioecy of the species and showed that the species did not display any apparent sex-specific dimorphism outside the reproduction period or any apparent sex-specific requirement for environment conditions.


Agroforestry Spatial analysis Local perception Dioecious species Spatial segregation of sexes Protected area 



This study was supported by IFS (International Foundation for Science) through a grant to GNG (No: D/4794-1) and by European Union (FP6 INCO-dev 031685) through SUN Project (Tools for Management and Sustainable Use of Natural Vegetation in West Africa). The authors acknowledge the support of farmers from Tanguiéta and Karimama districts.


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Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  • Gerard Nounagnon Gouwakinnou
    • 1
  • Anne Mette Lykke
    • 2
  • Bruno Agossou Djossa
    • 1
  • Brice Sinsin
    • 1
  1. 1.Laboratory of Applied Ecology, Faculty of Agronomic SciencesUniversity of Abomey-CalaviCotonouBenin
  2. 2.Department of Terrestrial Ecology, National Environmental Research InstituteAarhus UniversitySilkeborgDenmark

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