Livestock induces strong spatial heterogeneity of soil CO 2 , N 2 O and CH 4 emissions within a semi-arid sylvo-pastoral landscape in West Africa

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