Spatial patterns of riparian vegetation community composition and diversity along human‐ affected East African highland streams

Abstract

Riparian vegetation, which plays important roles in conservation of regional biodiversity and provision of many environmental services, has been severely degraded in East Africa by human activities. To ameliorate this degradation, more knowledge of the vegetation and factors affecting it is required. Thus, effect of land use on the plant community composition, species richness and diversity patterns were investigated along 18 streams in the Gilgle Gibe River catchment, in south-western Ethiopia, using 100 m 2 plots established along transects on both sides of the streams at 35 sampling locations beside land designated as agricultural, forested, mixed vegetation or eucalyptus plantation. The communities in the plots were surveyed and classified by Two-Way Indicator Species Analysis. In total, 107 vascular plant species belonging to 49 families were recorded. Species richness and diversity were lowest along streams beside agricultural land, which had narrow riparian buffers, and highest along forested streams, which had wider riparian buffers. The communities in the sampling plots were assigned to seven groups. Species richness was positively correlated buffer width (r = 0.74, p < 0.01). The results highlight the human influence on riparian vegetation and the importance of sustainable management that is compatible with its conservation and restoration. However, to address the severity and complexity of forest fragmentation, conservation strategies must embrace a multi-site, contextual approach.

The Natural Consequences of Land Use Change on Transformation and Vegetation Development in the Upper Odra Floodplain

“…River valley ecosystems are some of the most vulnerable areas to human transformation on Earth. The high biodiversity of the floodplains of natural rivers is closely linked to the constant remodeling of relief that rejuvenates riparian habitats [1] but, nowadays, the functioning of the natural environment increasingly depends on human activity and its intensity [2][3][4][5][6][7]. Man influences the environment both in the use of natural resources and in taking various types of conservation measures [8] with the aim of maintaining ecological balance.…”

“…The anthropogenic disturbance of riparian ecosystems leads to a reduction in biodiversity and synanthropization of the existing vegetation, and also creates conditions for the entry of alien or unusual species for a given habitat [19,20]. This often manifests itself in the increase in the number of anthropogenic communities, the disappearance of original species combinations, the creation of new heterogeneous species combinations, the creation of species-poor and less diverse communities and even the artificial planting of trees through forest reclamation [7,18,[21][22][23].…”