Changes in the availability and uses of wild yams according to climatic dryness and land-cover in Western Burkina Faso (West Africa): a joint ecological and ethno-botanical approach using GIS and remote-sensing

Abstract

The regional variability in the uses of wild yams is assessed according to their availability in relation with land-use and climatic conditions from the South to the North sudanian sectors in Western Burkina Faso. The study involves Weld studies and modelling of the geographical distribution of yams and seeks correlations between environmental and ethno-biological data. Terrain analysis consists of phyto-ecological surveys and interviews with local inhabitants. A cluster analysis of a multi-date image of data obtained by remotesensing is used to assess land-cover. The Bayesian post-probabilities of occurrence of each species are inferred using Weight of Evidence modelling linked to a Geographical Information System. The model is implemented with land-cover units and annual Moisture Availability Index evidential-layers and is driven by species presence data. The probabilities of occurrence of each species throughout the whole area as well as within and without the protected areas and in the vicinity of the sites of enquiries are calculated. A multi-factorial analysis makes it possible to shed light on the relationships among land use, the availability of yams, the uses of yams, knowledge and local practice. Results provide statistical J.-L. Devineau (&) UMR 5145 CNRS -UR 136 IRD, Technoparc, 5, rue du Carbone,

Understanding the contribution of wild edible plants to rural social-ecological resilience in semi-arid Kenya

“…These results further suggest that the majority of variation in WEP consumption can be predicted by household characteristics (Table 3) and the access conditions (Table 4) of specific harvest areas. Devineau et al (2008) come to a similar conclusion following their GIS analysis of the availability and consumption of wild yams. They find that the use of this food resource does not correlate directly with the species distribution, but rather, they suggest that WEP consumption is related to factors outside of resource availability such as cultural traditions and unpredictable climate that increases vulnerability.…”

“…Household characteristics related to increased reliance on WEPs can be considered one measure of vulnerability or system sensitivity, which is how food insecurity, lack of off-farm income, and low assets have been identified previously (Ladio and Lozada 2003, Paumgarten 2005, Mithofer et al 2006, Devineau et al 2008. In addition to identifying WEP user-group demographics, other researchers have found WEP consumption trends and NTFP harvest activities related to access conditions and management regimes (Berkes et al 2000, Pardo-De-Santayana et al 2005, Widayati et al 2010.…”

“…Ethnobotanical studies have investigated the various household factors that affect local ecological knowledge (LEK) and use of wild foods, such as income level, proximity to local markets, and the age, sex, and education level of the head of household (Somnasang and Moreno-Black 2000, Byg and Balslev 2001, Reyes-García et al 2005. The issue has also been approached from a resource management perspective, where conservation restrictions, land tenure, community organizations, and environmental conditions have been correlated with changes in WEP consumption (Ladio and Lozada 2003, Paumgarten 2005, Devineau et al 2008. Farm size is a particularly interesting variable because more private land provides greater unabated access to WEPs for the owners who can harvest these resources while farming (Price 1997), but may not be inclined to do so because households with greater wealth and assets often avoid WEPs due to the social stigma of eating the "food of the poorest" (Kepe 2008:543).…”

“Ordinary biodiversity” in western Burkina Faso (West Africa): what vegetation do the state forests conserve?

“…Three images on June 3, 2001, June 22, 2002and December 28, 2001 of the 196-052 ETM? satellite scenes were analysed (Devineau et al 2008). Three main landform units were recorded: (1) gravelly Conserv (2009Conserv ( ) 18:2075Conserv ( -2099Conserv ( 2079 soils and hardpan which are non-arable soils, (2) mid-and up-slopes that correspond to leached ferruginous red soils and (3) down-slopes which include hydromorphic soils characterised by a non-red colour on the surface.…”

To what extent does land-use affect relationships between the distribution of woody species and climatic change? A case study along an aridity gradient in western Burkina Faso

“…However, the association of land-cover remote-sensed data with climatic data has proven to be useful for modelling the current distribution of some savannah species (Devineau et al 2008).…”