Regeneration dynamics in acacia tortilis subsp. raddiana in Tunisia's Bou Hedma national park [Dynamique de la régénération d'Acacia tortilis subsp. raddiana dans le parc national de Bou Hedma en Tunise]
Jaouadi W.,Institute National Of Recherches En Genie Rural |
Hamrouni L.,Institute National Of Recherches En Genie Rural |
Hanana M.,Center de Biotechnologie de la Technopole de Borj-Cedria |
Mechergui K.,Institute National Of Recherches En Genie Rural |
And 2 more authors.
Bois et Forets des Tropiques | Year: 2012
This study was conducted in Bou Hedma national park, which is in Tunisia's arid zone and was listed as a Unesco Biosphere Reserve in 1977. The park harbours Tunisia's only tree steppe region with Acacia tortilis (Forsk.) Hayne subsp raddiana (Savi) Brenan. Our approach involves a combination of satellite imagery, vegetation surveys and observations of the dendrometric characteristics of this Acacia species. Our interpretation of the satellite images shows that Acacia tortilis occupies a very large area (12 % of the park's total area) and is essentially located in zones with characteristically skeletal soils, as in grazing prohibition zones or detritic-colluvial deposits. The species also prefers zones more than 200 m above sea level, with deep soils and shallow slopes. Overall, observed Acacia tortilis cover is mostly less than 10%, with a very significant presence of young naturally regenerating seedlings more than 10cm in diameter.
Durant S.M.,UK Institute of Zoology |
Durant S.M.,Wildlife Conservation Society |
Wacher T.,Conservation Programmes |
Bashir S.,Birdlife International Asia |
And 40 more authors.
Diversity and Distributions | Year: 2014
Biodiversity hotspots understandably attract considerable conservation attention. However, deserts are rarely viewed as conservation priority areas, due to their relatively low productivity, yet these systems are home to unique species, adapted to harsh and highly variable environments. While global attention has been focused on hotspots, the world's largest tropical desert, the Sahara, has suffered a catastrophic decline in megafauna. Of 14 large vertebrates that have historically occurred in the region, four are now extinct in the wild, including the iconic scimitar-horned oryx (Oryx dammah). The majority has disappeared from more than 90% of their Saharan range, including addax (Addax nasomaculatus), dama gazelle (Nanger dama) and Saharan cheetah (Acinonyx jubatus hecki) - all now on the brink of extinction. Greater conservation support and scientific attention for the region might have helped to avert these catastrophic declines. The Sahara serves as an example of a wider historical neglect of deserts and the human communities who depend on them. The scientific community can make an important contribution to conservation in deserts by establishing baseline information on biodiversity and developing new approaches to sustainable management of desert species and ecosystems. Such approaches must accommodate mobility of both people and wildlife so that they can use resources most efficiently in the face of low and unpredictable rainfall. This is needed to enable governments to deliver on their commitments to halt further degradation of deserts and to improve their status for both biodiversity conservation and human well-being. Only by so-doing will deserts be able to support resilient ecosystems and communities that are best able to adapt to climate change. © 2013 John Wiley & Sons Ltd.
Daly-Hassen H.,University of Carthage |
Kasraoui M.,Regie dexploitation forestiere Ref |
Karra C.,Direction generale des forets
Bois et Forets des Tropiques | Year: 2014
Tunisia still relies on imports to satisfy 90% of its domestic demand for timber and timber products, despite an increase in forest cover of some 500,000 ha in the last fifty years. The main aim of this study was to assess the share of Tunisia's forests in supplying needs for industrial timber over the last fifty years, and to determine the capacities of its timber industries to process locally-sourced timber. Consumption of industrial timber increased from 0.19 M m3 in 1961 to 1.30 M m3 in 2012, while industrial timber production increased by only 0.09 M m3 over the same period. In the current context of market liberalisation, industrial timber processing and reduced dependence on imports can only be achieved with effective coordination between all players in the forests and timber sector (government departments responsible for forest management and timber sales, logging companies and industries) to enhance the sector's competitiveness. An increase of 50,000 m3 of local timber and industrial timber products on the market would generate an additional 1.5 million of Tunisian dinar (M DT) (+22 %) for the State budget, reduce imports by 12 M DT (3 % of timber and timber product imports) and increase added value in the domestic timber sector by 4 M DT, as well as creating jobs in the logging and timber processing.
Kaabeche M.,Ferhat Abbas University Setif |
Benkheira A.,Direction Generale des Forets |
De Foucault B.,British Petroleum
Acta Botanica Gallica | Year: 2010
The main object of the authors is to present the plant community of Argania spinosa (L.) Skeels in Algeria. The distribution area of this forest tree in the district of Tindouf (Algeria) is identified for the first time. Using phytosociological method adapted to plant community of arid and Saharan land, this study describes three new syntaxa: Faidherbio albidae - Arganietum spinosae, Periploco angustifoliae - Rhoetum tripartitas and Acacio-Arganion spinosae. The Argania community is submitted to important damages by most populations which explain the regression of its current distribution area. Argania spinosa - hamada - ecology - syntaxonomy - Algeria.
Ecology, physical and production characteristics of the steppe with Acacia tortilis in the Bouhedma national park (Tunisia southernmost) [Étude des secteurs écologiques, du milieu physique et des caractéristiques de production de la steppe arborée à Acacia tortilis dans le parc national de Bouhedma (Tunisie méridionale)]
Jaouadi W.,Institute National des Recherches en Genie Rural |
Mechergul K.,Institute National des Recherches en Genie Rural |
Gader G.,Direction Generale des Forets |
Khouja M.L.,Institute National des Recherches en Genie Rural
Revue d'Ecologie (La Terre et la Vie) | Year: 2013
The present study was conducted in the Bouhcdma national park and its surroundings, located in the arid area of Tunisia and considered a Biosphere reserve by UNESCO in 1977; it is a protected area with special ecological characteristics and an important dynamics of space occupation.Thc park contains the only wooded steppe with Acacia tortilis (Forsk.) Hayne subsp raddiana (Savi.) Brcnan var. raddiana Brcnan in Tunisia. With the aim of safeguarding and management of the park, a better knowledge of the distribution patterns and dynamics of the vegetation of this zone makes it possible to consider programmes of restoration and sustainable management of the natural environment. Based on the interpretation of remote sensing data and use of SIG, the study was devoted to the elaboration of charts relating to the ecological systems present in 2005, and to the distribution of the steppe with Acacia tortilis according to physical factors such as slope, altitude, type and depth of the soil. Also, the production of seeds was studied to explain the effect of physical factors on the regeneration of the species. The analysis of soil occupation dynamics translates into a good distribution (7056 ha) of steppe with Acacia tortilis. The study shows that Acacia tortilis is located on 6242 ha at an altitude of 20 m to 150 m and on 814 ha at an altitude from 150 to 250 m. This species grows on 5815 ha with a weak slope (0 to 3 %), on 928 ha with a slope of 3 to 5 % and only on 313 ha with a slope > 5 %. The results show that the Acacia tortilis is regenerated on the not very advanced soil of hydrous contribution with a surface of 3832 ha, on rendzina with 1280 ha, the isohumic soil with a surface of 986 ha. Acacia tortilis colonizes the far from deep soil with a surface of 2796 ha, the fairly deep soil with a surface of 2175, the very deep soil with a surface of 1970 ha, the not very deep soil with a surface of 75 ha and the deep soil with a surface of 40 ha.
Changes of the breeding population of Ferruginous Duck Aythya nyroca at Lake Tonga (Northeast Algeria) [Statut et phénologie de la reproduction du Fuligule nyroca Aythya nyroca au lac Tonga (Nord-Est Algérien)]
Lazli A.,Center University dEl Tarf |
Boumezbeur A.,Direction Generale des Forets |
Moali A.,University of Abderrahmane Mira de Béjaïa
Alauda | Year: 2012
Between 2006 and 2008 the breeding population of Ferruginous Duck, has been monitored by weekly censuses of adults, males and females, and families (female + chicks) at Lake Tonga (north-eastern Algeria), the most important nesting site of the species in southern Mediterranean. The following breeding parameters have been studied: dates of laying and hatching, clutch size and breeding success. The breeding population was estimated at 466 males and 427 females in 2006, 376 males and 375 females in 2007 and at 734 males and 728 females in 2008. Pairing takes place between mid March and early April. Laying is recorded during a period of 8 to 10 weeks from mid April to early July. A brood size of 4, 7 ± 1, 3 young (n = 159) was recorded in the first study year, another of 6 ± 1,6 young (n = 220) in the second year and of 5,8 ± 1.44 young (n = 267) in the third year. Young fledged between July and early October. Our study investigates the evolution of this population in order to assess its status and to develop a national action plan for its protection. Data collected during this study show an increase of the population relative to existing data on this site obtained in 1991-1992.