Ecological challenges for the buffer zone management of protected areas of forest-savannah mosaic in West Africa

In sub-Saharan Africa, the management of buffer zones around protected areas does not often take into serious account the needs of resource exploitation by the local populations or the conservation needs of these areas. We described the ecological characteristics and management issues affecting the buffer zone around the Fazao-Malfakassa National Park; a 192,000-ha protected area in central-western Togo of utmost conservation importance within the Dahomey Gap region. Within the buffer zone (10 km radius, 334,800 ha), we focussed on four high conservation value areas totalling 65,594 ha (20% of the total buffer zone area). Using 2015 sentinel-2 images we analyzed land cover patterns and described existing ecological zones. We complemented these with field surveys and interviews with 300 people living in 22 villages within the buffer zone to describe the conditions affecting the resident human population. Although over 60% of the total buffer zone area is degraded, we identified four areas of high conservation value (total area = 65,594 ha). Interviewees recognized that slash-and-burn was the most common form of land use, followed by agroforestry practices. Agriculture, charcoal, and firewood production were the main drivers affecting habitats, and land conflicts were recurrent due to the rise in human population. The decline in agriculture, reported by interviewees in some sectors, was attributable to ravages of crops by elephants. Three independent diversity indices showed that, in preserved zones, a greater diversity of animals (with similar utilization frequencies) were hunted than in degraded sites (where grasscutters were the dominant hunted species). There were also significant differences between degraded and preserved zones in terms of plants used for charcoal production and for non-timber forest products. We advocate the development of community-controlled hunting areas to enhance the conservation value of the four well-preserved zones. Instead, promoting sustainable agricultural production systems in the degraded areas can help to further stabilize the agricultural front and reduce land pressure on the park

Pyridine and ammonia as probes for FTIR analysis of solid acid catalysts

Pyridine and ammonia have been used as probe molecules for the quantitative analysis of surface acidity of some solid catalysts by FTIR spectroscopy. For pyridine, a scale of acidity and an evaluation of the relative acid strength at different temperatures (373-773 K) were obtained for both Bronsted- and Lewis-acid sites. Correlation was verified between the concentration of Bronsted sites and the catalytic activity of the catalysts examined for the dehydration of 2-(2-hydroxyethyl)pyridine to 2-vinylpyridine. In contrast, ammonia was a much less reliable probe, mainly due to the overlapping of the resulting IR absorption bands. Moreover, it decomposed even at rather low temperatures, when adsorbed onto the catalysts

FT-IR and EPR spectroscopic analysis of La1-xCexCoO3 perovskite-like catalysts for NO reduction by CO

A FT-IR and EPR spectroscopic investigation has been carried out on a series of La1-xCexCoO3 (x=0-0.15) perovskite-type catalysts, which are quite active for the reduction of NO by CO, and a mechanism has been proposed for this reaction. The first step involves the oxidation of CO by the catalyst, followed by the dissociative adsorption of NO onto the catalyst surface. Finally, adsorbed nitrogen (N-ads) yields N2O, N-2 and NCOads along three parallel paths. Thus, oxygen exchange between NO and CO seems to occur indirectly and involves a surface oxygen vacancy. The catalytic activity is decreased by the substitution of Ce4+ for La3+ in the perovskite-type structure, which reduces the mobility of bulk oxygen. Activity is partially restored for x greater than or equal to 0.05 due to the presence of a segregated cerium oxide phase