A Methodological Approach to Model the Grass-Tree Relationship in \u3cem\u3eQuercus suber\u3c/em\u3e Mediterranean Forest Ecosystems

Livestock is socially and economically an important component for the livelihood of resource poor farmers in North Africa. A portion of livestock feed resources is forest rangeland. Unfortunately, the sustainability of this resource is threatened by anthropogenic pressures. In this study a number of silvo-pastoral management systems were proposed to maintain the ecosystem balance, and to cope with Mediterranean climate variability and the negative impacts of human activities and population pressure. For this reason it was important to examine the major relations within the North African forest ecosystems, which is composed mainly of Quercus suber trees. The aim of this work was to develop models relating fodder production as the dependent variable to the independent variables; Quercus suber canopy cover, ecological factors, and human pressure. This paper presents the methodological approach used in the Kroumiry-Mogody (Tunisia) and Mamora (Morocco) forests of North Africa. Initially, a forest inventory based on stratified sampling was conducted looking at density, height, and canopy cover. A comparative study was later established. In parallel, a survey was conducted in the surrounding agglomerations to assess the impact of human activities. The buffer technique was used to establish the relationship between fodder production and distribution, canopy cover, and human pressure. The methodology involved the creation of a specific zone around each agglomeration, which was mainly a function of the distance to the forest, the topographical features, and the number of domestic animals. The proposed approach will provide forestry managers with the ability to determinate different levels of anthropogenic pressure and to respond with contingency measures for each of these levels

Nutraceutical potentialities of Tunisian Argan oil based on its physicochemical properties and fatty acid content as assessed through Bayesian network analyses

Abstract Background Argan oil is traditionally produced by cold pressing in South-western Morocco where rural population uses it as edible oil as well as for its therapeutic properties which give them in counterpart valuable income. Given the economical interest of this oil, several attempts of fraudulency have been registered in the world global market leading to loss of authenticity. Our purpose is to launch a program of Tunisian Argan oil valorization since trees from this species have been introduced sixty years ago in Tunisia. The first step was thus to characterize the physicochemical properties and determine the chemical composition of Tunisian Argan oil in order to assess its quality. Methods Physicochemical parameters of oil quality were determined according to the international standard protocols. Fatty acid content analysis of Argan oils was performed by gas chromatography coupled to mass spectrophotometry. A comparative study was realized among Tunisian, Moroccan and Algerian samples differing also by their extraction procedure. The impact of geographical localisation on the fatty acids composition was studied by statistical and modeling Bayesian analyses. Results Physicochemical parameters analysis showed interestingly that Tunisian Argan oil could be classified as extra virgin oil. Argan oil is mainly composed by unsaturated fatty acids (80%), mainly oleic and linoleic acid (linoleic acid was positively influenced by the geographical localization (r = 0.899, p = 0.038) and the P/S index (r = 0.987, p = 0.002)) followed by saturated fatty acids (20%) with other beneficial compounds from the unsaponifiable fraction like polyphenols and carotenoids. Together with fatty acid content, these minor components are likely to be responsible for its nutraceutical properties and beneficial effects. Conclusion Tunisian Argan oil displayed valuable qualitative parameters proving its competitiveness in comparison with Moroccan and Algerian oils, and could be therefore considered as extra virgin edible oil for nutraceutical purposes as well as for cosmetic use