Contributed by Morgan Ruelle
Subsistence farmers in the Semien Mountains of Ethiopia maintain a rich legacy of plant diversity, including many plants they know how to use as medicine. These farming communities are encountering a number of complex changes, including population growth, new road construction and local effects of global climate change. Favorable market prices induce farmers to increase production of a few cash crops, often decreasing crop diversity and increasing the amount of land under permanent cultivation. As land use changes, medicinal plants may be eliminated from the landscape, thereby diminishing important local health care options.
Our research team is conducting human ecological research in the Debark District on the western slopes of the Semiens (2600-3000 metres above sea level). We are exploring the ways that farmers conserve plants and contribute to their food and health sovereignty. Over the past two years, we have conducted 199 interviews, including multiple visits with eighteen farming families in villages along an altitudinal gradient. To elicit indigenous ecological knowledge related to plants, we employ a variety of ethnobotanical techniques including participatory mapping, free-listing, preference ranking and pile sorting.
Participatory mapping with farmers has shown that most families tend to plants and animals in multiple fields and grazing areas in different directions from their houses (see Figure 6). Although outsiders often describe land ownership in Debark as “fragmented”, this pattern provides access to a greater diversity of plants in different parts of the landscape, including many medicinal plants that are associated with specific habitats.
Within these varied environments, free-listing activities have identified 142 useful plants, of which 29 have medicinal uses. Of these medicinal plants, 5 (17%) are cultivated, 14 (48%) are non-cultivated, and 8 (28%) are occasionally cultivated.
Preference ranking activities help us understand the relative significance of plants as medicines. We selected the 18 plants most frequently described as medicines. We found that on average, each family recognized 10 out of the 18 plants as medicines. Only one plant (haregresa, Zehnaria scabra) was recognized as a medicine by all participants, and was also consistently ranked as one of the most important medicinal plants. Other than Z. scabra, the plants were ranked by different families in different ways, indicating a diversity of knowledge and use of medicinal plants within our study area.
During pile sorting activities, participants arranged plant names into categories of their own choosing. Findings indicate that medicinal plants are often used in many other ways. For example, although indod (Phytolacca dodecandra) was identified as a medicine by 10 out of 18 families during preference ranking, it was sorted by most participants based on its usefulness for washing clothes (see Figure 7). The use of indod as soap reinforces health sovereignty by improving hygiene. These observations suggest that the conservation of medicinal plants is driven by multiple uses broadly related to health.
There is no question that loss of biodiversity poses a grave threat to health sovereignty in the Semien Mountains. Plants are essential to human health, not only because they are primary sources of food and medicine, but because they perform many other vital functions within food and health systems. Access to a variety of plants means that farmers have multiple options to meet their needs; these choices are fundamental to their health sovereignty. Therefore, despite pressures to devote all of their land to cash crops, farmers are conserving plant diversity. Research should support farmers’ conservation efforts to maintain health sovereignty in an era of dramatic change.