Papers by Boutheina STITI
The aim of the current study was to investigate the effect of geographic origin in mineral compos... more The aim of the current study was to investigate the effect of geographic origin in mineral compositions on the Q. canariensis acorns. The results showed that there were significant (p « 0.5) differences between populations for macronutrients Sodium (Na), Calcium (Ca), Potassium (K)) except for Phosphorus (P) and for all studied micronutrients: Iron (Fe), Manganese (Mn) and zinc (Zn). Potassuim contents of acorn ranged from 5,638 to 7,667 mg/g MS with highest being for Nefza acorn and lowest for Bni Mtir ones. It is the highest macronutrients for all population. However Iron was the most abandon micronutrient, varied widely from 0,491 mg/g MS (Bni Mtir) to 1,230 mg/g MS (Nefza). No significant differences were recorded for Heavy metal. The concentrations of Chromium (Cr), Nickel (Ni) and Cobalt (Co) in acorns flour are null. On the other hand Cadmium (Cd) and Copper (Cu) were found but with concentrations which were much lower than that the acceptable limits for herbs and spices by WHO.
BOIS & FORETS DES TROPIQUES, 2021
In Mediterranean forests, besides the conflict between forest managers and local populations who ... more In Mediterranean forests, besides the conflict between forest managers and local populations who are often poor and dependent on livestock for survival, the cost of raw materials used in animal feed is increasingly a burden for farmers. There is growing recognition that wise use of acorns can reduce feed costs and enhance sustainable participatory governance of these woodlands. This paper aimed to carry out a quantitative, qualitative and economic evaluation of acorn potential in a cork oak forest in north-western Tunisia and to investigate the impact of their post-dispersal on natural regeneration. Quantities were estimated in November and February, respectively for acorns collected directly from trees and from the ground. Time-dependent monitoring of acorn quality and numbers of new seedlings was also conducted from autumn 2014 to spring 2015. The results show a significant decrease in acorn quantity from 5.28 ± 4.61 t/ha in November to 0.684 ± 0.1 t/ha in February. However, this ...
In Mediterranean forests, besides the conflict between forest managers and local populations who ... more In Mediterranean forests, besides the conflict between forest managers and local populations who are often poor and dependent on livestock for survival, the cost of raw materials used in animal feed is increasingly a burden for farmers. There is growing recognition that wise use of acorns can reduce feed costs and enhance sustainable participatory governance of these woodlands. This paper aimed to carry out a quantitative, qualitative and economic evaluation of acorn potential in a cork oak forest in north-western Tunisia and to investigate the impact of their post-dispersal on natural regeneration. Quantities were estimated in November and February, respectively for acorns collected directly from trees and from the ground. Time-dependent monitoring of acorn quality and numbers of new seedlings was also conducted from autumn 2014 to spring 2015. The results show a significant decrease in acorn quantity from 5.28 ± 4.61 t/ha in November to 0.684 ± 0.1 t/ha in February. However, this ...
South African Journal of Botany
Polymers
The aim of the present study was to extract starch from acorn (Quercus suber L.) fruits using wat... more The aim of the present study was to extract starch from acorn (Quercus suber L.) fruits using water and alkaline methods. Structural and functional properties of extracted starches were investigated and compared to those of corn and modified starches in order to determine their innovative potential application in food industry. The yield of extraction using the two methods was about 48.32% and 48.1%. The isolated starches showed low moisture, fat and protein contents, revealing high purity and quality. Additionally, the starch extracted using the alkaline method (AAS) showed higher lightness (60.41) when compared to starch isolated using hot water (WAS). However, the lightest white color was found for studied commercial starches. Moreover, AAS starch exhibited the highest swelling power, solubility and water absorption, followed by WAS and commercial starches. Results showed that extracted acorn starches were characterized by greater enthalpy and gelatinization temperatures. Similar...
As natural regeneration and direct sowing have been considered difficult, planting was adopted as... more As natural regeneration and direct sowing have been considered difficult, planting was adopted as a solution to attenuate the decline of cork oak forest. However, Tunisian planted cork oaks showed a troublesome phenomenon characterized by the presence of creeping plants which has a negative influence on height growth and cork production. This study aimed to estimate, for the first time in Tunisia, the percent of creeping cork oaks among those planted between 1995 and 2008 and to make a diagnosis in order to propose solutions to this problem. The percentage of creeping plants was determined in 2014 within 35 plots installed in 13 perimeters, situated in northern Tunisia. Crown diameter and total height were measured for the whole plants. Moreover, the creeping plants were were distinghished and inventoried in categories according to shoot ramification. The average survival rate, estimated at 55±30%, varied between 0% and 100% depending on perimeter. The average percentage of creeping...
Journal of Food Chemistry & Nanotechnology
The investigation was conducted on oil extracted from mature acorns of Quercus suber L. harvested... more The investigation was conducted on oil extracted from mature acorns of Quercus suber L. harvested from three different Tunisian sites. The content of total polyphenols, tannins and flavonoides were determined. Antimicrobial activities were also evaluated. Antimicrobial activity of this oil was tested against: Escherichia Coli, Bacillus subtilis and Candida albicans. Gentamicin and amphotericin B were respectively used as a positive reference for bacteria and fungi. Discs without samples were used as a negative control. Fixed oil of cork oak acorn was extracted by the soxhlet apparatus. The oil content, expressed as dry weight, ranged from 0.9 to 2.02%. Fixed oil extracted from acorns of cork oak showed a high amount of total polyphenols 18.93 mg GAE/g. Amounts of flavonoids and tannins were also important. The results showed a significant antimicrobial effect against B. subtilis and C. albicans with inhibition diameter of 10.6 mm and 9.8 mm, respectively.
Forests
Forest ecosystems are an important anthropogenic pillar to human wellbeing, providing a multitude... more Forest ecosystems are an important anthropogenic pillar to human wellbeing, providing a multitude of ecosystem services. In Mediterranean countries, where climate change effects are exponentially increasing, the value of the forest ecosystem services is even higher and their preservation is more crucial. However, the biophysical and economic value of such services is usually not observable due to their non-marketable characteristics, leading to their underestimation by decision-makers. This paper aims to guide decision-making through a set of new management scenarios based on ecosystem services’ values and their spatial distribution. It is a cumulative multidisciplinary study based on biophysical models results, economically valued and implemented using the geographic information system (GIS) to analyze spatial data. The investigation was based on a biophysical and economic valuation of cork, grazing, carbon sequestration and sediment retention as a selection of ecosystem services p...
African Journal of Ecology, 2016
Journal of Asia-Pacific Biodiversity, 2016
L'état actuel des peuplements de chêne liège est inquiétant. Ces peuplements sont constitués en g... more L'état actuel des peuplements de chêne liège est inquiétant. Ces peuplements sont constitués en grande partie de vieux sujets. Leur dégradation progressive résulte d'une combinaison de facteurs biotiques et abiotiques qui ne cessent de s'intensifier. L'homme y a profondément modifié l'équilibre qui existe dans l'écosystème. Il a perturbé les microclimats par le défrichement, l'incendie, les coupes d'arbres, la levée du liège mal effectuée et surtout le pâturage. La régénération naturelle est par conséquent quasi absente. Avec l'échec des semis directs, la régénération assistée par la plantation de plants produits en pépinière est désormais la méthode la plus employée pour la réhabilitation de ces subéraies.Ceci nécessite la conservation des glands sains, à court et à moyen termes pour pallier le problème de l'irrégularité de la fructification du chêne-liège, et l'amélioration des techniques de production des plants. Sur le plan pratique, il convient d'écourter le séjour des plants en pépinière et d'utiliser la technique de l'autocernage, par l'utilisation des conteneurs en hors-sol, et il est préférable de préparer le sol mécaniquement. Le comportement hostile de la population usagère; surtout vis-à-vis des mises en défens qui conditionne le succès des travaux de régénération,nécessite un compromis entre la population locale et les gestionnaires pour un aménagement rationnel et durable de la subéraie. Abstract The current state of cork oak stands is worrisome. These stands are made up largely of old
Malgré l'importance économique du liège, les recherches sur sa production et sa qualité sont asse... more Malgré l'importance économique du liège, les recherches sur sa production et sa qualité sont assez rares en Tunisie. Afin de contribuer à l'amélioration de la gestion de la production de liège de reproduction, la croissance et la qualité du liège ont été évaluées dans la forêt de Bellif, située au nord ouest de la Tunisie. 16 parcelles ont été choisies et 5 arbres ont été échantillonnés et des plaques de liège de 20x20 cm ont été prélevées sur tous les arbres. La porosité a été mesurée par observation directe de lenticelles à l'aide d'une loupe. La densité, l'humidité, l'épaisseur et l'accroissement annuel du liège ont été déterminés. En moyenne, l'épaisseur du liège était de 41.4 mm. Plus que 50% des échantillons appartiennent aux classes commerciales aptes au bouchonnage. Les échantillons présentent une forte densité moyenne (296.15 kg/m 3 ) ce qui diminue leur qualité. Les échantillons de liège étudiés rentrent dans la catégorie des lièges réguliers, moyennement poreux et présentant des tachesjaunes.
Compte tenu de l'état actuel de dégradation des subéraies, la reconstitution du couvert végétal d... more Compte tenu de l'état actuel de dégradation des subéraies, la reconstitution du couvert végétal doit être assurée par un aménagement approprié de l'espace. Ceci nécessite une base de données sur le potentiel des ressources naturelles, jusqu'ici peu évalué en Tunisie. Ce travail s'intéresse à la distribution spatiale et à la biodiversité des espèces arbustives dans la subéraie de Ain Snoussi, localisée au Nord Ouest de la Tunisie. La méthode des transects combinée à la méthode du plus proche voisin a été utilisée. Dans chacune des six parcelles sélectionnées dans la forêt d'étude, deux transects orthogonaux de 50m de long ont été installés. Chaque transect comprend 1 point d'observation tous les mètres (50 points au total). A partir de chaque point d'observation, la distance à l'arbuste le plus proche a été mesurée et les paramètres morphologiques de la plante ont été relevés. Cinq espèces ont été identifiées; un indice de Shannon de 1.44 et une équitabilité de Piélou proche de 1 révèlent respectivement une faible diversité spatiale et une abondance relative similaire des cinq espèces d'arbustes, avec une légère dominance d'Erica arborea (indice de Berger-Parker = 0.36). En moyenne, la densité végétale arbustive était de 8692 plants/ha et son phytovolume total de 8277,52m 3 /ha.
Depredation of the acorns cork oak by the insects and its impact on the potential of germination ... more Depredation of the acorns cork oak by the insects and its impact on the potential of germination and seedling growth were studied in a mountain cork oak forest in northwestern Algerian. The rate of pre-germinated acorns on the ground is higher than for other acorns. The weight is the most distinctive variable for all the acorns; whatever their condition and provenance, it varies significantly from 0.76 to 6.76 g. Regarding the damage to acorns, statistical tests show no significant difference in the length and weight, it is not very significant for the width.The infestation of acorns is independent of their size. The acorns attacked by beetles are clearly dominant (72%) compared with those attacked by moths (28%). 20% severely damaged acorns germinate and produce viable seedlings. But the germination rate decreases with the increase of injuries. Growth is strongly affected by the rate of damage to acorns. One therefore concludes that a major attack in the cotyledons certainly does not act on germination, but can affect the strength of the resulting plant and its survival.
Understanding the patterns of land-cover change for biodiversity and ecology system function has ... more Understanding the patterns of land-cover change for biodiversity and ecology system function has been important in landscape ecology. The objective of this study was to analyze land-cover change in the Ain Snoussi area of northern Tunisia. Landsat MSS/4 and SPOT HRV/3 images were used for the analysis. To classify land-cover type into forest and non-forest area, pixel-based classification and maximum likelihood algorithm were applied to two imageries using supervised classification algorithm. After classification of images, each changed area was calculated. Thereby, analysis of distance roads and topographic factors such as elevation, slope, aspect, and Topographic Wetness Index (TWI) were performed. The results showed that the area changed into non-forest was slightly larger than that into forest. Moreover, most of the changed areas, approximately half of the total changed area, were distributed near the roads. In addition, the change from forest to non-forest area tends to have a negative and positive relationship respectively with elevation and slope. On the other hand, the change from non-forest to forest area showed the tendency to be negative in elevation, slope, and TWI. However, the slope aspect of study area did not have any particular relationship with change tendency. In conclusion, spatial pattern of land-cover change was influenced by the distance from roads and topographic characteristics of target area.
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Papers by Boutheina STITI