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Biodiversity matters in many aspects for human well-being by providing timber and non-timber products. The most important ecosystems providing these products in West Africa are savannas. In the context of land-use changes, there is an urgent need to understand the impact of land-use on savanna vegetation and biodiversity. This study assesses the impact of land-use on savannas by comparing protected and communal areas. Vegetation relevés were performed in the W National Park and its surrounding communal area in Burkina Faso. Vegetation types were established using ordination and clustering methods. We analyzed to find which environmental factors determine the occurrence of the vegetation types and whether land-use has a specific effect on diversity of vegetation types occurring in both areas. Furthermore, we tested the effect of land-use on vegetation structure and the occurrence of life forms and highly valued tree species. Our results reveal five vegetation types occurring in both areas. Elevation and soil characteristics played the most important role for the occurrence of the vegetation types. Land-use had an effect on vegetation structure, diversity, and the occurrence of life form and highly valued species. Our findings suggest that traditional human land-use does not automatically lead to loss of species and degradation of savanna habitats and that combination of communal and protected areas may be of great importance for the conservation of broad spectrum of biodiversity. Our study demonstrates the complexity of land-use impact on biodiversity patterns and provides insights on what kind of management activities may be most appropriate in both areas.

Abstract:Termites are renowned ecosystem engineers. Their mounds have been described as an important element of savanna vegetation dynamics, but little is known about their large-scale impact on vegetation composition. To investigate the influence of termite-induced heterogeneity in savannas along a climatic gradient in West Africa termite mound vegetation was compared with adjacent savanna vegetation using 256 paired plots (size of the termite mound and a corresponding savanna area) in five protected areas from northern Burkina Faso to northern Benin. On each plot vegetation and soil sampling was performed. Additionally bioclimatic variables from the WORLDCLIM database were used. The vegetation on the mounds and the surrounding savanna differed within all study sites (DCA length of gradient 3.85 SD) and showed complete turnover along the climatic gradient (DCA length of gradient 5.99 SD). Differences between mounds and savanna were significantly related to termite-induced changes in soil parameters, specifically clay enrichment and increased cation concentrations (base saturation). On a local scale, termite-induced differences in soil conditions were found to be the most important factor affecting mound vegetation, while on a regional scale, annual precipitation showed the strongest significant correlations. However, with increasing precipitation, differences between mounds and the surrounding matrix became more pronounced, and the contribution of mounds to local phytodiversity increased. Eleven plant species were identified as characteristic termite mound species. In the more humid parts of the gradient, more characteristic plant species were found that may benefit from favourable soil conditions, good water availability, and a low fire impact in the mound microhabitat.

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The florae of Central European cities and towns differ largely from the flora of the hinterland. Characteristics of the urban flora (in comparison to that of the hinterland) are: a remarkable decrease in the percentage of indigenous and archeophytic species, in particular of those that have a narrow ecological amplitude and/or are strictly bound to oligotrophic habitats; an increase in the population of a small group of indigenous species resulting from a change from natural to synanthropic habitats (apophytisation, synanthropisation); an immigration of alien species (neophytes), in particular to disturbed habitats; and the development of new ecotypes. The origin and development of the typical features of the Central European urban flora can be divided into four distinctive periods: the time up until the end of the 15th century, the time from the 16th century to the beginning of the industrial age, the industrial age, the post-industrial age.

Riparian forests are classified as endangered ecosystems in general, particularly in sahelian countries like Burkina Faso because of human-induced alterations and civil engineering works. The modification of this important habitat is continuing, with little attention being paid to the ecological or human consequences of these changes. The objective of this study is to describe the variation of woody species diversity and dynamic in riparian forests on different type of watercourse banks along phytogeographical gradient in Burkina Faso. All woody species were systematically measured in 90 sample plots with sides of 50 m × 20 m. Density, dominance, frequency and species and family importance values were computed to characterize the species composition. Different diversity indices were calculated to examine the heterogeneity of riparian forests. A total of 196 species representing 139 genera and 51 families were recorded in the overall riparian forests. The species richness of individuals with dbh ≥ 5cm increased significantly from the North to the South along the phytogeographical gradient and varied significantly between the different types of riparian forests. Similarity in tree species composition between riparian forests was low, which indicates high beta diversity and reflects differences in habitat conditions and topography. The structural characteristics varied significantly along the phytogeographical gradient and between the different types of riparian forests. The diameter class distribution of trees in all riparian forests showed a reverse "J" shaped curve except riparian forest of stream indicating vegetation dominated by juvenile individuals. Considering the ecological Foundation project: This work was financially supported by University of Frankfurt and BIOTA West project The online version is available at Responsible editor: Chai Ruihai importance of riparian forest, there is a need to delineate and classify them along watercourses throughout the country.

Aim  Africa is expected to face severe changes in climatic conditions. Our objectives are: (1) to model trends and the extent of future biome shifts that may occur by 2050, (2) to model a trend in tree cover change, while accounting for human impact, and (3) to evaluate uncertainty in future climate projections. Location  West Africa. Methods  We modelled the potential future spatial distribution of desert, grassland, savanna, deciduous and evergreen forest in West Africa using six bioclimatic models. Future tree cover change was analysed with generalized additive models (GAMs). We used climate data from 17 general circulation models (GCMs) and included human population density and fire intensity to model tree cover. Consensus projections were derived via weighted averages to: (1) reduce inter‐model variability, and (2) describe trends extracted from different GCM projections. Results  The strongest predicted effect of climate change was on desert and grasslands, where the bioclimatic envelope of grassland is projected to expand into the desert by an area of 2 million km2. While savannas are predicted to contract in the south (by 54 ± 22 × 104 km2), deciduous and evergreen forest biomes are expected to expand (64 ± 13 × 104 km2 and 77 ± 26 × 104 km2). However, uncertainty due to different GCMs was particularly high for the grassland and the evergreen biome shift. Increasing tree cover (1–10%) was projected for large parts of Benin, Burkina Faso, Côte d’Ivoire, Ghana and Togo, but a decrease was projected for coastal areas (1–20%). Furthermore, human impact negatively affected tree cover and partly changed the direction of the projected change from increase to decrease. Main conclusions  Considering climate change alone, the model results of potential vegetation (biomes) show a ‘greening’ trend by 2050. However, the modelled effects of human impact suggest future forest degradation. Thus, it is essential to consider both climate change and human impact in order to generate realistic future tree cover projections.