No abstract

No abstract

Changing woody plant density across agricultural landscapes of the Sudano-Sahelian region is a debated issue. This paper reports the results of an investigation on the contribution of field hedges to overall woody plant density. Hedges separating individual cropped parcels were studied within village agropastoral territories in the Dantiandou district in western Niger. In 1992, field hedges were mapped over the study area using aerial photography and in 2016, using high resolution Google Earth imagery. In 1992, field hedge length was equal to 1006 km within 435 km² of croplands, equivalent to 2.3 km km-2. In 2016, 17.5% of these hedges had disappeared, but 1591 km of new hedges were observed resulting in an increased density of hedges to 5.6 km km-2. In 24 years, hedges had increased at a mean annual rate of 3.7% likely associated with the splitting of crop fields by inheritance. The composition and productivity of hedges were also monitored in 1996, 2010 and 2015. All trees (maximum height ≥4m), shrubs (<4m) and tussock perennial grasses were recorded within twelve field hedge samples of 200m each. Field measurements were used to estimate basal area, crown area, foliage mass and wood mass of each woody plant within the sampled hedges. No significant trends were found between 1996 and 2015 in woody plant density, basal area, crown cover, wood and foliage masses across all monitored hedges. However, overall means hide a slight decrease in tree contributions, while shrub contributions first increased and then decreased. They also mask contradictory trends among sites most likely related to different rates of shrub coppicing and tree cutting. The woody species composition of the hedges is poor with an increase of Combretum glutinosum to the detriment of Guiera senegalensis over the study period. Multiplying the hedge sample statistics by the changing lengths of field hedges in the study area provides estimates of the contribution of the hedge woody plants to the woody plant population at a landscape scale. Between 1992 and 2016, field hedges contributed to increases of woody plant density by 3.9%, basal areas by 5.4% , crown cover by 2.7% , leading to 6.1% annual increase in foliage mass and 8.8% increase in wood mass.

Livestock productivity in West African Sahel is constrained by seasonal scarcity of feed and by its low quality in the dry season. Feed resources scarcity in the region has also been aggravated by the increase in livestock population, which has heightened the demand for feed, particularly in periurban areas. Livestock feed markets have thus sprung up in many cities and towns. To understand the dynamics of these markets, surveys were conducted in five of them in Maradi and five others in Niamey, Niger, in the early dry season (October-November 2019), late dry season (March-June 2020), and wet season (August-September 2020) with a semi-structured questionnaire. Results showed that diverse feed types were sold or bought, and mainly by adult male vendors or buyers, in both markets across seasons. The buyers gave as major reasons for purchasing livestock feed the insufficient household feed biomass, the poor-quality household feed, and the need for supplementary feeds to maintain and improve animal performance. Prices of livestock feeds at both markets varied significantly with season, market location and feed type. In both sites, prices of legume residues (cowpea hay, cowpea husk, groundnut haulm) were higher than the other feed types. Results further showed that there was no clear relationship between price and nutritional quality across seasons.

No abstract