Alexandre Ickowicz

How do pastoral families combine livestock herds with other livelihood security means to survive? The case of the Ferlo area in Senegal

Reducing vulnerability to hazards is a major challenge for pastoral settlements in the dry lands of sub-Saharan Africa. Accumulation of a stock of living animals is a major means of livelihood security that pastoralists use to cope with their constraints, amongst which is high environmental variability. Diversification and long-distance mobility are other means of livelihood security, implying specific family organization. We analysed the combination of these means in ensuring the livelihood security of 508 familial settlements in the rural community of Ferlo, Tessekre (Senegal). At least 40% of the settlements surveyed were small pastoral families, composed of one or two households with small herds (less than 50 cows and 50 sheep). Herds were the major means of livelihood security, but due to lack of a sufficient labour and other assets, the situation of these impoverished families was very precarious. In 28% of the settlements, families combined livestock, crops and non-farming activities as livelihood means. The remaining 32% of the settlements were pastoral settlements supported by large cattle herds and, in many cases, the production of Aïd el Kebir rams (for the major Muslim religious event). Non-farming activities were also present in these settlements with large herds, especially activities in the livestock trade. Diversification can reinforce the function of herds as savings accounts and might also enable the pastoralists to invest in livestock activities. There were three groups of settlements based on the characterization of livelihood security strategies used by pastoral herders. Over time, pastoralists have to utilize several means of security to cope with climatic shocks such as droughts, and familial events such as the death of the familial chief. Family organization (dispersal or grouping), diversification and mobility are important means used to recover after major losses of animals.

Livestock induces strong spatial heterogeneity of soil CO2, N2O and CH4 emissions within a semi-arid sylvo-pastoral landscape in West Africa

Greenhouse gas (GHG) emissions from the surface soils and surface water receiving animal excreta may be important components of the GHG balance of terrestrial ecosystems, but the associated processes are poorly documented in tropical environments, especially in tropical arid and semi-arid areas. A typical sylvo-pastoral landscape in the semi-arid zone of Senegal, West Africa, was investigated in this study. The study area (706 km² of managed pastoral land) was a circular zone with a radius of 15 km centered on a borehole used to water livestock. The landscape supports a stocking rate ranging from 0.11 to 0.39 tropical livestock units per hectare depending on the seasonal movements of the livestock. Six landscape units were investigated (land in the vicinity of the borehole, natural ponds, natural rangelands, forest plantations, settlements, and enclosed plots). Carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) fluxes were measured with static chambers set up at 13 sites covering the six landscape units, and the 13 sites are assumed to be representative of the spatial heterogeneity of the emissions. A total of 216 fluxes were measured during the one-year study period (May 2014 to April 2015). At the landscape level, soils and surface water emitted an average 19.8 t C-CO2 eq/(hm²•a) (CO2: 82%, N2O: 15%, and CH4: 3%), but detailed results revealed notable spatial heterogeneity of GHG emissions. CO2 fluxes ranged from 1148.2 (±91.6) mg/(m²•d) in rangelands to 97,980.2 (±14,861.7) mg/(m²•d) in surface water in the vicinity of the borehole. N2O fluxes ranged from 0.6 (±0.1) mg/(m²•d) in forest plantations to 22.6 (±10.8) mg/(m²•d) in the vicinity of the borehole. CH4 fluxes ranged from–3.2 (±0.3) mg/(m²•d) in forest plantations to 8788.5 (±2295.9) mg/(m²•d) from surface water in the vicinity of the borehole. This study identified GHG emission “hot spots” in the landscape. Emissions from the surface soils were significantly higher in the landscape units most frequently used by the animals, i.e., in the vicinity of the borehole and settlements; and emissions measured from surface water in the vicinity of the borehole and from natural ponds were on average about 10 times higher than soil emissions.