Change in the woody floristic composition, diversity and structure from protected to unprotected savannahs in Pendjari Biosphere Reserve (Benin, West Africa)

Abstract

Savannahs are widespread vegetation type in Sudanian zone of Africa. As protected areas are often assumed to be the best way to conserve biodiversity, we assessed the effectiveness of the Pendjari Biosphere Reserve in Benin, for maintaining savannah woody species composition, diversity and structure. Square plots of 900 m 2 were randomly established in protected and surrounding unprotected savannahs, and all woody species (dbh ! 1 cm) were recorded and identified. Species composition, Importance Value Index, densities, basal area and diversity indexes were assessed in relation to conservation status. The results showed that DCA based on presence/absence species data did not separate clearly protected savannahs from unprotected ones. However, some species were prominent in unprotected savannahs while others showed the same scheme in protected ones. Diversity indexes indicated a good distribution of species in the two savannah types. The woody density showed a higher value in protected than unprotected savannah at shrub layer level. The basal area was significantly higher in the protected savannah than unprotected one at the two woody layer levels. It can be concluded that biodiversity conservation in surrounding unprotected areas should be of great importance to increase biodiversity conservation by protected area whether specific actions were implemented.

Vegetation changes over the past two decades in a West African savanna ecosystem

“…In accordance with Houehanou et al. (), we suggest that the decreasing evenness might be due to increased livestock herds. Browsers, mainly goat, particularly favor specific browse species, such as Anogeissus leiocarpa (Lykke, Kristensen, & Ganaba, ).…”

“…Agriculture in West Africa is traditionally practiced in the form of shifting cultivation, which allows a recovery of the soil fertility during fallow periods (Mendoza‐Vega & Messing, ) and the re‐establishment of natural vegetation. Numerous studies (Houehanou et al., ; Nacoulma et al., ; Schmidt et al., ; Shackleton, ) have focused on the impact of land use on African savanna ecosystems by comparing the vegetation and biodiversity between protected and communal areas. In eastern Burkina Faso, a vegetation type‐specific impact of land use on plant diversity was observed; the highest impact was found on vegetation types with a high degree of anthropogenic disturbances (cultivation, grazing), whereas no impact on diversity was found in rarely grazed and never cultivated vegetation types with poor soils (Nacoulma et al., ).…”

Caught in a human disturbance trap: Responses of tropical savanna trees to increasing land-use pressure

“…Our set of key species corresponds well with previous findings from protected North-Sudanian savannas; all key species (except Crossopteryx febrifuga) were frequently found to have IVI values P10% (Ouédraogo et al, 2009;Gnoumou et al, 2011;Houehanou et al, 2013b). C. febrifuga populations tend to have a clumped spatial dispersion and might for this reason not be well-represented in other studies.…”

Assessment of Habitat Change Processes within theOti-Keran-Mandouri Network of Protected Areas in Togo (West Africa) from 1987 to 2013 Using Decision Tree Analysis

“…Forest ecosystems and wildlife habitats are currently under high human pressure and climate change impacts in West Africa [10][11][12], particularly in Togo [13]. In this country, forest cover is being highly reduced with serious impacts on ecosystem resilience to climate change [14].…”