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National Science Foundation (USA) 2001

Regulation of the Hydrologic and C Cycles by Native Shrubs in Soils of Sub-Sahelian Africa

Hydrologic Carbon Cycles Shrubs


Titre : Regulation of the Hydrologic and C Cycles by Native Shrubs in Soils of Sub-Sahelian Africa

Organismes NSF : Division Of Earth Sciences (EAR)

Durée : September 1, 2001 — August 31, 2008

Soil degradation in relation to desertification of Sub-Sahelian Africa is a major concern. Farmers of semiarid land are being considered to be paid for practices that sequester C in soils, which could enable farmers in vulnerable ecological landscapes to adopt practices that promote sustainability and improve soil quality and degraded environments. However, assessing soil degradation and the potential to sequester C is spatially and temporally complex in this semiarid landscape. In particular, we have identified a largely unrecognized component in the landscape of the vast semi-arid Sahel, namely woody shrubs (Piliostigma reticulatum and Guiera senegalensis) that voluntarily regrow in farmers’ fields after the summer cropping season. These shrubs seem to be much more important than trees or other organic inputs such as animal manure at the landscape level in regulating C inputs/sequestration and hydrologic processes. Under current management farmers who cut and burn the shrub biomass each spring are not utilizing this organic matter effectively. An intriguing ancillary theory is that these shrubs may do "hydraulic lift". This has been documented in other semiarid regions and is the process of water movement from moist subsoil to dry surface layers using root systems as a conduit which can be released from roots to surrounding soil during periods when transpiration ceases (usually at night) This could drive rhizosphere processes in "dry" soil such as nutrient mineralization and mobility and possibly provide small amounts of water to shallow rooting crop species during dry periods.
The overall objectives are to (1) quantify annual C cycling and storage, water balance, and litter decomposition of two dominant shrubs of Sub-Sahelian agroecosystems ; (2) couple indigenous knowledge to biogeochemical and hydrological results with the ecology of these shrubs ; and (3) use modeling to determine the effect of alternative shrub management systems on soil C and soil quality at the landscape level. The work has implications for large areas of Sub Sahelian West Africa that have similar agroecosystems to Senegal. The approach will be multidisciplinary and the ecological research of these shrubs would be a basis for practical applications in agricultural nutrient and water management, and as a viable management tool to off set soil degradation and promote C sequestration to reduce global climate change

Partenaire (s) : Richard Dick dick.78 (Principal Investigator) Aminata Badiane (Co-Principal Investigator) Mamadou Khouma (Co-Principal Investigator) Modou Sene (Co-Principal Investigator) S.A. Samba (Co-Principal Investigator)

Financement : $1,216,694.00

Présentation (National Science Foundation)

Page publiée le 13 mai 2017, mise à jour le 29 octobre 2017