Climate Variability in the Sudano-Guinean Transition Area and Its Impact on Vegetation: The Case of the Lamto Region in Côte D’Ivoire

Based on unique 50-year datasets from 1962 to 2011, this study diagnoses the variability of climate at Lamto (6.13°N, 5.02°W) in Côte d’Ivoire. A combined pluviothermal index is used to identify climate regions of West Africa. The interdecadal change of the climate is analyzed along with a discussion on the West African Monsoon (WAM) circulation. The impact of vegetation is also analyzed. It is shown that Lamto has mainly a subhumid climate but, in some particular years, this area has a humid climate. Two decades (1962–1971 and 2002–2011) exhibit rainfall excess and the last three ones (1972–1981, 1982–1991, and 1992–2001) show a rainfall deficit that affected West Africa in the early 1970s. The meridional wind field from 1000 hPa to 700 hPa is used to study the WAM variability. The level of the WAM is the lowest (~860–890 hPa) during the active period of the northern wind coming from the Sahara desert (November–February). During 1962–1971 and 2007–2009, the depth of the monsoon at Lamto reaches 300 hPa with an increase in the rainfall. A relationship between potential evapotranspiration and the climate highlights rainfall deficit in 1969 and rainfall excess in 2001–2011

PRELIMINARY TECHNOLOGICAL PROPERTIES ASSESSMENT OF BACILLUS SPP. ISOLATED FROM TRADITIONAL CASSAVA STARTERS USED FOR ATTIEKE PRODUCTION

This study was carried out to select Bacillus strains as potential microbial starters for cassava dough fermentation into attiéké (a fermented and steamed granular cassava, couscous-like product) regarding their enzymes (amylase, pectinase, cellulase, phytase, tannase and betaglucosidase) production. For this purpose, 42 presumptive Bacillus spp were isolated from traditional cassava starters and screened in vitro. All the selected strains produced amylase, pectinase, cellulase while 37 (88.09%) produced phytase and 27 (64.28%) were able to produce beta-glucosidase. Regarding these technological properties mainly production of all these enzymes, only 13 Bacillus strains (30.95%) could be used as potential microbial starters in association with lactic acid bacteria for the controlled fermentation of cassava dough in order to improve and standardize the organoleptic quality of attiéké by softening and detoxification actions

PRELIMINARY TECHNOLOGICAL PROPERTIES ASSESSMENT OF BACILLUS SPP. ISOLATED FROM TRADITIONAL CASSAVA STARTERS USED FOR ATTIEKE PRODUCTION

This study was carried out to select Bacillus strains as potential microbial starters for cassava dough fermentation into attiéké (a fermented and steamed granular cassava, couscous-like product) regarding their enzymes (amylase, pectinase, cellulase, phytase, tannase and betaglucosidase) production. For this purpose, 42 presumptive Bacillus spp were isolated from traditional cassava starters and screened in vitro. All the selected strains produced amylase, pectinase, cellulase while 37 (88.09%) produced phytase and 27 (64.28%) were able to produce beta-glucosidase. Regarding these technological properties mainly production of all these enzymes, only 13 Bacillus strains (30.95%) could be used as potential microbial starters in association with lactic acid bacteria for the controlled fermentation of cassava dough in order to improve and standardize the organoleptic quality of attiéké by softening and detoxification actions

Updated African biomass burning emission inventories in the framework of the AMMA-IDAF program, with an evaluation of combustion aerosols

African biomass burning emission inventories for gaseous and particulate species have been constructed at a resolution of 1 km by 1km with daily coverage for the 2000–2007 period. These inventories are higher than the GFED2 inventories, which are currently widely in use. Evaluation specifically focusing on combustion aerosol has been carried out with the ORISAM-TM4 global chemistry transport model which includes a detailed aerosol module. This paper compares modeled results with measurements of surface BC concentrations and scattering coefficients from the AMMA Enhanced Observations period, aerosol optical depths and single scattering albedo from AERONET sunphotometers, LIDAR vertical distributions of extinction coefficients as well as satellite data. Aerosol seasonal and interannual evolutions over the 2004–2007 period observed at regional scale and more specifically at the Djougou (Benin) and Banizoumbou (Niger) AMMA/IDAF sites are well reproduced by our global model, indicating that our biomass burning emission inventory appears reasonable

Sorghum head-bugs and grain molds in West and Central Africa: I. Host plant resistance and bug–mold interactions on sorghum grains

A regional sorghum head-bug and grain mold resistance trial was conducted in 1996 and 1997 at 15 and 13 research stations located in 10 West and Central African countries, respectively. Two cultivars namely IS 14384 and CGM 39/17-2-2 exhibited consistently high levels of resistance both to head-bugs and grain molds over years and localities. Eurystylus oldi was the dominant head-bug species at all localities except in Benin, Chad and Guinea. Sorghum grain mycoflora varied little between sites with genera Phoma and Fusarium dominating, followed by Curvularia. Efficiency of the insecticidal treatment on head-bug incidence partially confirmed the critical role played by head-bugs in aggravating mold infectio

The possible role of local air pollution in climate change in West Africa

The climate of West Africa is characterized by a sensitive monsoon system that is associated with marked natural precipitation variability. This region has been and is projected to be subject to substantial global and regional-scale changes including greenhouse-gas-induced warming and sea-level rise, land-use and land-cover change, and substantial biomass burning. We argue that more attention should be paid to rapidly increasing air pollution over the explosively growing cities of West Africa, as experiences from other regions suggest that this can alter regional climate through the influences of aerosols on clouds and radiation, and will also affect human health and food security. We need better observations and models to quantify the magnitude and characteristics of these impacts

Climate variability in the Sudano-Guinean transition area and its impact on vegetation : the case of the Lamto region in Cote d'Ivoire

Based on unique 50-year datasets from 1962 to 2011, this study diagnoses the variability of climate at Lamto (6.13 degrees N, 5.02 degrees W) in Cote d'Ivoire. A combined pluviothermal index is used to identify climate regions of West Africa. The interdecadal change of the climate is analyzed along with a discussion on the West African Monsoon (WAM) circulation. The impact of vegetation is also analyzed. It is shown that Lamto has mainly a subhumid climate but, in some particular years, this area has a humid climate. Two decades (1962-1971 and 2002-2011) exhibit rainfall excess and the last three ones (1972-1981, 1982-1991, and 1992-2001) show a rainfall deficit that affected West Africa in the early 1970s. The meridional wind field from 1000 hPa to 700 hPa is used to study the WAM variability. The level of the WAM is the lowest (similar to 860-890 hPa) during the active period of the northern wind coming from the Sahara desert (November-February). During 1962-1971 and 2007-2009, the depth of the monsoon at Lamto reaches 300 hPa with an increase in the rainfall. A relationship between potential evapotranspiration and the climate highlights rainfall deficit in 1969 and rainfall excess in 2001-2011