Conservation science for common ground: Developing tools to manage livestock grazing in the Bale Mountains of Ethiopia

Understanding when human encroachments may push an ecosystem beyond the limits of sustainability is a task made difficult by the complexity and dynamical nature of ecosystems. Establishing baseline conditions and monitoring key ecological attributes are crucial first steps, but they may be insufficient to predict the full consequences of mounting threats. Remote sensing of vegetation patterns is widely used as an assay of landscape condition but the critical links between satellite-derived vegetation data and the trophic interactions that stem from them are still mostly not well understood. I propose to establish these links in the Afroalpine ecosystem of Bale Mountains National Park (BMNP) in Ethiopia through ground-truthing of the relationships between cattle, vegetation and rodents and inputting sequential assessment of vegetation condition, acquired from satellite imagery and ground-truthing, into a spatially explicit trophic model. This step is imperative for identifying the “condition envelope” for vegetation within which a system may be resilient to human-induced landscape change and could be used both to adaptively manage human activities and sustain biodiversity.

The Afroalpine and surrounding areas support an exceptionally high diversity of rare and endemic species, establishing the region as one of 34 biodiversity hotspots in the world. BMNP encompasses the continent’s most extensive range of Afroalpine habitats, which is essential habitat for the rarest canid species, the Ethiopian wolf. This endemic canid feeds upon an n-species guild of rare endemic rodents.

However, over the last 20 years the BMNP has been used to graze increasingly high numbers of livestock that are thought to have impacted on rodent abundance. Investigating the effects of livestock grazing on the functioning of this ecosystem has been identified as the leading research priority in the recently formulated BMNP management plan.

The overall goal of this study is to quantify the indirect interaction between rodent density and demography, and livestock grazing pressure. Critical links between forage conditions, livestock grazing pressures and rodent assemblages will be made through field investigation. Existing data and ongoing studies of the linkages between rodent populations and wolf demography will parameterise a trophic model, that will be used to establish the composition and density of rodents required to sustain desired wolf numbers and the amount of vegetation required to maintain sufficient rodent assemblages. This research addresses the highest research priority identified by BMNP.