Land degradation assessment in drylands (LADA) and carbon sequestration

World Drylands (P/ET=0.05 to 0.065)

Drylands characteristics  Complexity, variability, resilience, vulnerability, extensive, changing (continual transition), poverty.  Superficies of drylands in sub-Saharan Africa : 30%? (TERRASTATS, FAO)

Interdependency of Services for human well-being in drylands  Provisioning services: food, fibre, fuels, timber, minerals, pharmaceuticals, fresh water  Regulating services : maintenance of biodiversity, climate regulation, hydrological regulation, decomposition of wastes  Cultural and social services: spiritual and social values, aesthetic values,migration/transhumance  Supporting services: soil formation, primary production, pollinisation of plants, provision of habitat, carbon sequestration

“Threaten drylands”  70% degraded at various levels of severity (UNEP, 2003)  Degraded lands with variable extent according to countries  Few data exist on extent, causes, driven forces, direct and indirect consequences and trends of land degradation  Need for assessment and monitoring of the phenomenon

LADA PARTNERSHIP LADA PARTNERSHIP At national and regional levels National CCD focal institutions, land and water divisions Regional bodies of UNCCD, CST, TPNs At international level The LADA Secretariat is hosted by FAO and can be contacted at: LADA Secretariat, AGLL Food and Agriculture Organization of the United Nations, FAO, Viale delle Terme di Caracalla, Rome, Italy Fax: Phone:

LADA Objectives 1.Develop and test an effective assessment methodological framework for land degradation in drylands 2. Assess (quantitative, qualitative and georeferenced) land degradation at global, national and sub-national levels to: * Identify the Status, driving forces and impacts as well as trends of land degradation in drylands in all its components including physical resources (such as soils, water, vegetation, biodiversity) and human resources (livelihood systems, cultural societies),

LADA Objectives (ctnd) * Identify and characterize the hotspots: the areas with greatest land constraints, high risks or high level of on going land degradation of such areas and areas under risks of degradation, drought or floods, * Identify and characterize the bright spots: the areas where the degradation has been slowed or reversed through conducive policies and actions (area of success & priority area for most cost-effective rehabilitation of fragile lands), 3. Build national, regional and global assessment capacities for land degradation to assist in the design, planning and monitoring of interventions to mitigate land degradation and establish sustainable land use and management practices

CS Potential in drylands  According to FAO, 2002: - Quantities of carbon in drylands soils (Xerosols and Yermosols):7kg/m2 - Stock of carbon in Arid AEZ : 4kg/m2 for 1m depth *According to Woomer and al. 2003: C stock in the Sahel: 20,6tC/ha for 40cm depth

Degraded drylands and Carbon  Hot Spots: area of significant loss of C due to land degradation  Bright Spots: area of good potential for carbon sequestration through soil rehabilitation, agricultural intensification and environment protection

Hot and bright spots

Time Land use change Biomass S.O.M. & Productivity /Carbon sequestrat. How to measure Changes In land degradation and CS

SOIL-C Soil Carbon Spatial Decision Support System from customizing the CENTURY model from customizing the CENTURY model

Impact of land rehabilitation on CS (increasing of bright spots) ___________________________  According to IPCC (2000) : 0,25 t C/ha/year with an estimate potential of 3 to 7 Mt C/year respectively for 2010 and 2040 in drylands

Estimate of CS in arid zones according to soil management techniques (Lal, 1999 in FAO 2002)  Activity Quantity (t/ha/year)  Conservation tillage (0,1 – 0,2)  Mulch and soil cover (4-6 Mg/ha/year) (0,05 - 0,1)  Conservation agriculture (0,15 – 0,3)  Compost (20Mg/ha/year) (0,1 – 0,3)  Fertilisers management (1,0 – 0,3)  Water management (0,05 – 0,1)  Pastures zones (0,05 – 0,10)

Advantages of carbon management in drylands  Local level: improvement of soil quality,decreasing of land degradation, improvement of food security  National level: improvement of agricultural productivity and environment quality  Global level: increasing of biodiversity and positive contribution to global climate

LADA contribution to CS  i) accurate evaluation and estimation of land degradation in connection with the evaluation of carbon stocks: harmonized approach and same level of precision between countries, determination of level of severity of land degradation and risks of carbon loss;  (ii) identification of appropriate techniques for land rehabilitation and enhancement of carbon stocks: measures in carbon stocks changes with land rehabilitation assessment, inclusion of socio-economic factors;

LADA &CS  (iii) Data on relationship between land degradation-biodiversity-carbon sequestration  (iv) Provision of socio-economic data on dryland for the future development of carbon market at farmers communities level.

Activities/Perspectives  Pilot sites studies (in Senegal)  Web Sites:    Regional LADA Workshop with 17 African countries  Pipeline of regional projects concept note ( from the Dakar workshop, March 2003 with USGS/Eros data Center and CSE)  Formulation of FAO country TCP projects for a smooth implementation of LADA phase 2 funded by GEF