Human-climate induced drivers of mountain grassland over the last 40 years in Sidama, Ethiopia: perceptions versus empirical evidence

Abstract

Mountain grasslands are globally important ecosystems. They are considered as heritage sites with “outstanding values” to ecological communities by adding a further “layer and support to the existing protection measures.” However, mountain grasslands are increasingly under threat from human activities and impacts of climate change. Using satellite imagery, we studied land use/land cover (LULC) patterns between 1973 and 2015. Individual interviews consisting of 240 households for comparison and field data collection were conducted for accuracy assessment. Five categories of LULC types were identified from the image classification that included forestland, grassland, shrubland, bushland, and agricultural land. Between 1973 and 2015, the forestland, grassland, and shrubland covers were declined by 15.9%, 53.6%, and 41.0%, respectively. In contrast, bushland and agricultural land were increased by 169% and 647%, respectively. The overall LULC classification accuracies for the four reference years ranged from 77.6 to 86.5% with Kappa statistic of 0.69 to 0.80. The majority of respondents (92.5%) mentioned that the cover of forestland outsized the other land use land cover types followed by grassland in the past. The stated indicators of land use/land cover changes linked to the impact of climate change were decline in milk yield and crop production, spread of livestock diseases, degradation of grazing lands, and change in the timing of rain. The results of the study suggest that human-climate related components were major drivers of land use/land cover dynamics that demand for proper management and conservation of mountain grassland ecosystem in Sidama South Ethiopia.