|
|||||
|
|
Variation in vegetation cover and livestock mobility needs in Sahelian West Africa |
|
| Authors: | Matthew D Turner Bilal Butt Aditya Singh Leif Brottem Augustine Ayantunde Bruno Gerard |
| Institution: | 1. Department of Geography, University of Wisconsin, Madison, WI, USA;2. School of Natural Resources and the Environment, University of Michigan, Ann Arbor, MI, USA;3. Department of Forest and Wildlife Ecology, University of Wisconsin, Madison, WI, USA;4. Department of Political Science, Grinnell College, Grinnell, IA, USA;5. International Livestock Research Institute, B.P. 1496 Ouagadougou, Burkina Faso;6. International Maize and Wheat Improvement Center (CIMMYT), Texcoco, Estado de México, Mexico |
| Abstract: | A new approach was developed to evaluate the implications of the spatiotemporal variability of green vegetation for the dispersion of livestock that is required to access quality forage in semi-arid Africa. Maximum NDVI (Normalized Difference Vegetation Index) at 1 km2 resolution was determined for concentric rings (0–31 km radii) around 227 individual sample locations within the study area for 14 dates (between 1 April to 1 November) annually over the 2000–2010 period. A sigmoidal curve was fitted to points within the maximum NDVI × distance radii space to determine the asymptote distance (AD) – the radius at which further dispersion from the sample location does not lead to significant gains in access to green forage. AD was found to: increase with latitude (or increasing aridity); decline as the rainy season proceeds; and show no trend over the 2000–2010 period. These results introduce much-needed empirical data to current debates surrounding the scales of governance to support livestock mobility. |
| Keywords: | nonequilibrium ecology rangeland management NDVI climate change Mali |