Glades
Soil, vegetation and historical land use were investigated in nine peri-forest grasslands (glades) in the Harenna forest, Ethiopia. The aims of the study were to collect base line data in order to (1) provide a general characterization of the glades in terms of soil properties, vegetation and landuse, and to (2) infer hypothesis on their origin, with particular reference to possible anthropogenic versus natural origin. Three glades and three adjacent forest sites assessed at different altitudes within the Harenna forest. For both glades and controls a soil profile was described and soil analyzed for pH, TEB (Cmol(+)/Kg; Ca++, Mg++, K+, Na+), BS (%), Texture, CEC (Cmol(+)/Kg), EC (ds/m), OC (%) and TN (%). In eight of the glades above ground biomass was removed from five 50 cm x 50 cm plots, morpho-species were counted and (morpho-) Species Richness (SR) was calculated for each site; Dry Above Ground Biomass (DAGB) was weighted after drying (70°C, 24h) the samples of each morpho-species as occurring at each site. Historical landuse was also investigated through interviews with a key informant from Rira and casual interviews with local inhabitants. Glades tended to be associated with patches of low pH, TEB and BS as a result of increased leaching, probably vertically due to excessive drainage or due to water logging. Topography and drainage characteristics seemed to determine variation in vegetation type (forest vs. grassland). Grazing seemed to have negative effects on species richness and abundance (particularly of dicotyledons) but further investigation is needed to validate the results. A strong social network appears to be associated with the archipelago of glades within the broader forest, and are, thus, important both socially and biologically in the conservation of the area.
This research was undertaken by Giovanni Chiodi under the auspices of the Darwin Initiative funded Harenna project and the University of Aberdeen.