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Abstract: This study is concerned with the implications of changing latitudinal gradients in vegetative phenology (green-up, senescence, and length of growing season) for the management of long-distance seasonal movements of livestock herds in Sudano-Sahelian West Africa. For a study area covering much of the southern half of Mali, phenological parameters were estimated using a double-logistic function fitted to seasonal NDVI trajectories for 1km2 MODIS data over the period 2000–2010. Green-up dates, senescence dates and length of growing season were all found to more strongly vary by latitude (+9days/degree, −5days/degree and −14days/degree, respectively) than across years (+0.42days/year, +0.86days/year and +0.44days/year respectively). Interannual and spatial variability of these parameters are highest at lower latitudes within the study area. The slopes of the relationship of phenological parameters with latitude change across the latitudinal range studied. Breakpoint analysis of annual green-up versus latitude curves identifies a mean inflection point of 13° north latitude above which the positive slope declines significantly. This previously-undescribed pattern is consistent with recent work on monsoonal dynamics showing rainfall onset being associated with an abrupt shift in the location of the ITCZ (monsoon onset) at latitudes north of 13° north latitude. The effects of the observed variation in latitudinal gradients of phenological variables on the direction and timing of regional livestock movements are discussed. [Copyright &y& Elsevier]

The confluence of new understandings of dryland ecology and common property resource management has arguably led to a 'new pastoral development paradigm'-a paradigm that incorporates a widespread acceptance of the importance of livestock mobility within the context of devolving greater rangeland management authority to local groups. Despite over a decade of interest and attention generated by this new paradigm, little progress has been achieved on the ground. A major premise of this article is that this impasse results from persistent conceptual difficulties surrounding the relationship between livestock mobility, nonequilibrium ecology, and common property institutions. These difficulties are best resolved through work grounded in the social and ecological realities of particular regions. The promise of such engagements is illustrated through case material from the annual grasslands of Sahelian region of West Africa. The policy implications resulting from a reconceptualization of the relationship between property and dryland ecology are presented. [ABSTRACT FROM AUTHOR]