Silvopastoral area

The silvopastoral zone (SPZ) of Ferlo, Senegal is located in the Sahelian belt and covers an area of about 101,609 km² across five ecoregions: the Agricultural Expansion Region, the Eastern Transition Region, the Ferruginous Pastoral Region, the Northern Sandy Pastoral Region, and the Southern Sandy Pastoral Region.

The main livelihood in the SPZ consists of livestock production and rainfed agriculture. The main crops grown include millet, cowpeas and sorghum. Other sources income are derived from timber and arabic gum extraction, as well as fruit harvesting of Balanites aegyptiaca and Zizyphus mauritiana. These activities are divided into five distinct sub-systems: sylvopastoral, agrosylvopastoral, agropastoral, lower Ferlo valley and peri-urban.

The main type of land cover includes agricultural land, water bodies, wetlands, dry forests, shrublands, pastures and rangelands, urban areas and infrastructure. However, the diversity of land cover types in the SPZ reflects the complex interactions between human activities, natural resources and environmental conditions in the region. This represents a sustainable development challenge specific to the silvopastoral zone. Decades-long pressures from logging, agricultural expansion, overgrazing and other human activities are contributing to the gradual degradation of this region.

Measuring grazing intensity in the Ferlo region

Within the HANPP framework, grazing intensity and the availability of forage resources can be assessed and monitored. This allows for the spatial and temporal analysis of areas where overgrazing may occur, potentially leading to vegetation degradation.

A key indicator for this assessment is the ratio of HANPPharv and NPPact.

  • HANPPharv on grazing land reflects the biomass demand through livestock grazing and is calculated based on regional livestock numbers.
  • NPPact indicates the amount of herbaceous biomass produced on a given area, and thus the biomass available for grazing.
  • The HANPPharv:NPPact ratio provides insight into the pressure exerted on available forage resources in relation to their regenerative capacity. It is important to consider that only a portion of total NPP—namely the herbaceous and foliar biomass—is accessible and digestible for livestock, as opposed to woody biomass. This indicator also enables the comparison of regional feed availability with actual grazing demand, which is determined by livestock densities and prevailing feeding systems.

Implementation of the Great Green Wall

The Great Green Wall (GGW) initiative, launched by the African Union in 2007, aims to combat land degradation and desertification by restoring 100 million hectares of land across the Sahel region. In Senegal, one of the most prominent examples of GGW implementation is found in the Ferlo region—an area characterized by transhumant pastoralism as the dominant land-use system (Diop et al., 2018). However, the introduction of GGW activities has led to significant changes in land cover, including the enclosure of reforested zones, which contributes to the fragmentation of traditional pastoral spaces

The application of the HANPP framework offers valuable insights to better understand the implementation of the GGW initiative:

  • The tree cover area and their respective NPPact monitors and localizes the expansion and increasing greenness of the GGW
  • HANPPharv can be used to evaluate if harvest activities are affected by the implementation of the GGW, harvest on different plots can be compared, for example mono-cultural agriculture and forest gardens.
  • By comparing NPPpot and NPPact it is possible to monitor the potential NPP and the current NPP to detect productivity losses (HANPPluc). This provides a means to evaluate whether the GGW"s ecological restoration goals align with actual improvements in ecosystem productivity

References

  • Further references: Erb, K. H., T. Fetzel, T. Kastner, C. Kroisleitner, C. Lauk, A. Mayer, and M. Niedertscheider (2016), Livestock grazing, the neglected land use, in Social Ecology: Society-Nature Relations Across Time And Space, edited by H. Haberl et al., pp. 295–319, Springer, Dordrecht, Netherlands. DOI
  • Diop, S., Guisse, A., Sene, C., Cisse, B., Diop, N.R., Ka, S.D., Cisse, A.G., Sambou, S., Ndiaye, O., Fandohan, A.B., Chao, F., Guoqin, W., Yongdong, W., 2018. Combating Desertification and Improving Local Livelihoods through the GGWI in the Sahel Region: The Example of Senegal. J. Resour. Ecol. 9, 257–265.DOI

Senegal Country borders

Silvopastoral area