25 research outputs found

    Rural Dynamics and Forest Conservation in Northern Tunisia

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    This paper will first examine the causes of the ongoing forest crisis that was inherited from the French protectorate and that is associated with the agricultural and forest policies followed by the Tunisian government. Strict forest regulations have failed to contain increased population pressure on forest lands. This is mainly due to the crisis of traditional agriculture that has been undermined by large and modern production-driven exploitation of large basins, which is promoted by the agricultural policies of the state and supported by a powerful urban framework. Then, this article will show how, in recent decades, the multiplicity of original rural dynamics tends to give new clear-cut characteristics to the rural populations and their territories in the mountain forests. In particular, it focuses on issues like the reshaping of rural communities, diversification of peasants’ income generation activities, and the dynamism of certain peasant economy. These sufficiently advanced changes are lightening the pressure of the population on the forest lands, and they especially modify Man-vegetation relationships, towards the reconciliation between the peasants and the forests. They therefore call for a re-thinking of forest policies to clearly integrate resident peasants into forest management and development

    A new species for the spontaneous vascular flora of Tunisia: Rhus coriaria L.

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    This account describes the morphological characteristics, the auto-ecology and the economic and environmental values of Rhus coriaria, a specie which has been recently found in the northwestern side of Jebel GorrĂąa (Tunisian High Tell

    Joumine Marsh; National Park of Ichkeul, Tunisia: floristic diversity, vegetation mapping and dynamics (1925-2011)

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    The vegetation of Joumine Marsh (National Park of Ichkeul, Tunisia) has been studied from 2005 to 2011 with the aims: (1) to characterize the present-day status of the marsh vegetation based on plant inventories and phytosociological surveys, (2) to identify the influence of interannual hydrological changes on the plant distribution, and (3) to reconstruct, on the basis of previous works, the vegetation dynamics over the past 86 years (1925-2011). Results reveal the regression and sometimes the local extinction of the plants of temporary freshwater habitats, and their replacement by halophilous, cultivation-tolerant, footpath and grazing-tolerant species. Such changes express the artificialisation of the marsh. The mid-term dynamics of Joumine Marsh (1925-2011) is characterized by four periods: (1) before the first hydrological developments realized on the Joumine Wady in 1948, the marsh was dominated by the helophytic formation of Bolboschoenus glaucus and Schoenoplectus litoralis; (2) between 1948 and the putting into service of the Joumine Dam in 1982/83, the helophytic vegetation remained dominant; (3) between 1982-1983 and the summer 2002, because of an inappropriate management of the reservoir (without freshwater release), the salinity of the marsh has considerably increased, triggering the decline of the hydrophilous vegetation and the expansion of salt scrubs of Sarcocornia fruticosa; (4) finally, since autumn 2002, occasional releases of freshwater from the Joumine reservoir and the realization of new hydrological developments on the Joumine ditch lead to the inundation and washing of the marsh. These changes have induced the partial replacement of the salt scrubs by renewed helophytic herbaceous formations. This study reveals the significance of the ratio “hydro-hygrophilous plants/halophilous plants” as an indicator of the health of coastal wetlands. This ratio, as a simple tool for helping the management, may be used at the scale of the entire system lake-marsh of IchkeulLa vĂ©gĂ©tation du marais de Joumine (Parc National de l'Ichkeul, Tunisie) a Ă©tĂ© Ă©tudiĂ©e entre 2005 et 2011 dans les buts: (1) de caractĂ©riser l'Ă©tat actuel de la vĂ©gĂ©tation du marais sur la base d'inventaires floristiques et de relevĂ©s phytosociologiques, (2) d'identifier l'influence des changements hydrologiques interannuels sur la rĂ©partition de la vĂ©gĂ©tation, et (3) de reconstruire, sur la base de travaux antĂ©rieurs, la dynamique de la vĂ©gĂ©tation sur 86 ans (1925-2011). Les rĂ©sultats rĂ©vĂšlent la rĂ©duction, voire la disparition, des espĂšces infĂ©odĂ©es aux milieux temporaires d'eau douce, et leur remplacement par des espĂšces halophiles, adventices, rudĂ©rales et indicatrices de surpĂąturage. Ces changements dĂ©notent l'artificialisation du marais. La dynamique Ă  moyen terme de la vĂ©gĂ©tation du marais de Joumine (1925-2011) est caractĂ©risĂ©e par quatre pĂ©riodes: (1) avant les premiers amĂ©nagements hydrauliques rĂ©alisĂ©s sur l'oued Joumine en 1948, le marais Ă©tait dominĂ© par la scirpaie Ă  Bolboschoenus glaucus et Schoenoplectus litoralis ; (2) entre 1948 et la mise en service du barrage de Joumine en 1982/83, la scirpaie est restĂ©e dominante ; (3) entre 1982-83 et l'Ă©tĂ© 2002, sous l'effet d'une gestion inappropriĂ©e du barrage (sans lĂącher d'eau douce), la salinitĂ© du marais a considĂ©rablement augmentĂ©, provoquant le dĂ©clin de la vĂ©gĂ©tation hydro-hygrophile et l'extension de la sansouĂŻre Ă  Sarcocornia fruticosa ; (4) enfin, depuis l'automne 2002, des lĂąchers occasionnels d'eau douce Ă  partir du barrage de Joumine et la rĂ©alisation de nouveaux amĂ©nagements sur le canal de Joumine ont conduit Ă  l'inondation et au lessivage du marais. Ces changements ont entraĂźnĂ© le dĂ©clin de la vĂ©gĂ©tation halophile au profit de la rĂ©gĂ©nĂ©ration de la scirpaie. Cette Ă©tude met en Ă©vidence l'importance du rapport « vĂ©gĂ©tation hydro-hygrophile/vĂ©gĂ©tation halophile » en tant qu'indicateur de l'Ă©tat de santĂ© de marais littoraux. Ce rapport, qui apparaĂźt comme un outil simple d'aide Ă  la gestion, peut ĂȘtre exploitĂ© Ă  l'Ă©chelle de l'ensemble du systĂšme lac-marais de l'Ichkeul

    Rare, endemic and threatened vascular flora of Tunisian wetlands

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    Tunisian wetlands harbour a large floristic richness, estimated at 407 species representing 228 genera and 75 families. This flora comprises species strictly limited to wetlands, and species originating from surrounding lands. It is characterized by a big proportion of rare and/or threatened taxa (~ 29 %). Kroumirie is the richest region, with 290 taxa among which 54 are considered as very rare, rare or infrequent, because of their limited distribution area, generally located in frail or degraded ecosystems. The preservation of this exceptional biodiversity, threatened on short term, implies the urgent development of scientific investigations and adapted protection measuresLes zones humides de Tunisie prĂ©sentent une grande richesse floristique, Ă©valuĂ©e Ă  407 espĂšces reprĂ©sentant 228 genres et 75 familles. Ces espĂšces sont, soit strictement infĂ©odĂ©es aux zones humides, soit transgressives des milieux terrestres. Cette flore est caractĂ©risĂ©e par une forte proportion des taxons rares et/ou menacĂ©s (∌ 29 %). La Kroumirie est la rĂ©gion la plus riche, avec 290 taxons dont 54 sont considĂ©rĂ©s comme trĂšs rares, rares ou peu rĂ©pandus, en raison de leur rĂ©partition rĂ©duite et gĂ©nĂ©ralement situĂ©e au niveau d'Ă©cosystĂšmes trĂšs fragiles ou dĂ©gradĂ©s. La prĂ©servation de cette biodiversitĂ© exceptionnelle et menacĂ©e Ă  court terme nĂ©cessite la mise en place urgente d'Ă©tudes scientifiques et de mesures de protection appropriĂ©es

    Influence of grazing on structure, composition and dynamics of vegetation in Mediterranean temporary pools (northern Tunisia)

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    Three temporary pools of Sejenane region (northern Tunisia) have been studied with the aims of characterizing their vegetation, and of specifying the impact of grazing on their structure, composition and dynamics. Permanent transects of quadrats have been surveyed in spring and summer during two (not-grazed pool) to three years (grazed pools). The vegetation of the three pools is organized in three concentric belts related to the topographic gradient. The between-years dynamics is strongly characterized by the alternation of distinct spring and summer vegetations. Grazing appears as the main control of the composition and structure of hydrophytic plant communities. It prevents the colonization by competitive, perturbation-sensitive species, and favours the persistence of annual, light-demanding dwarf plants. In order to protect the biodiversity of these rare habitats in Tunisia, it is necessary to maintain, through an adapted management of grazing, a landscape mosaic of grazed and not-grazed zonesTrois mares temporaires de la rĂ©gion de Sejenane (Tunisie septentrionale) ont Ă©tĂ© Ă©tudiĂ©es afin de caractĂ©riser leur vĂ©gĂ©tation et de prĂ©ciser l’influence du pĂąturage sur sa structure, sa composition et sa dynamique intra- et interannuelle. Des transects de quadrats permanents ont Ă©tĂ© suivis au printemps et en Ă©tĂ© durant deux (mare non pĂąturĂ©e) Ă  trois ans (mares pĂąturĂ©es). Le cortĂšge floristique des mares Ă©tudiĂ©es est organisĂ© en trois ceintures concentriques liĂ©es au gradient topographique. La dynamique intra-annuelle de la vĂ©gĂ©tation est nettement marquĂ©e par l’alternance de cortĂšges printaniers et estivaux distincts. Le pĂąturage apparaĂźt comme le principal facteur contrĂŽlant la composition et la structure des communautĂ©s vĂ©gĂ©tales hydrophytiques. Il limite le dĂ©veloppement des espĂšces compĂ©titives sensibles aux perturbations et favorise le maintien d’une flore de petite taille, thĂ©rophytique et hĂ©liophile. Afin de prĂ©server la biodiversitĂ© de ces habitats rares en Tunisie, il apparaĂźt nĂ©cessaire de maintenir, par une gestion adaptĂ©e du pĂąturage, une mosaĂŻque paysagĂšre de zones non pĂąturĂ©es et pĂąturĂ©e

    Dynamiques rurales et conservation forestiĂšre dans le Nord de la Tunisie

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    This paper will first examine the causes of the ongoing forest crisis that was inherited from the French protectorate and that is associated with the agricultural and forest policies followed by the Tunisian government. Strict forest regulations have failed to contain increased population pressure on forest lands. This is mainly due to the crisis of traditional agriculture that has been undermined by large and modern production-driven exploitation of large basins, which is promoted by the agricultural policies of the state and supported by a powerful urban framework. Then, this article will show how, in recent decades, the multiplicity of original rural dynamics tends to give new clear-cut characteristics to the rural populations and their territories in the mountain forests. In particular, it focuses on issues like the reshaping of rural communities, diversification of peasants’ income generation activities, and the dynamism of certain peasant economy. These sufficiently advanced changes are lightening the pressure of the population on the forest lands, and they especially modify Man-vegetation relationships, towards the reconciliation between the peasants and the forests. They therefore call for a re-thinking of forest policies to clearly integrate resident peasants into forest management and development

    Une nouvelle espÚce pour la flore vasculaire spontanée de la Tunisie : Rhus coriaria L

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    Summary. — A new species for the spontaneous vascular flora of Tunisia : Rhus coriaria L.— This account describes the morphological characteristics, the auto-ecology and the economic and environmental values of Rhus coriaria, a specie which has been recently found in the northwestern side of Jebel GorrĂąa (Tunisian High Tell).Abaza Khaled, Gammar Amor Mokhtar, Ghrabi Gammar Zeineb. Une nouvelle espĂšce pour la flore vasculaire spontanĂ©e de la Tunisie : Rhus coriaria L. In: Revue d'Écologie (La Terre et La Vie), tome 65, n°2, 2010. pp. 179-184

    Le marais de Joumine, Parc National de l’Ichkeul, Tunisie : diversitĂ© floristique, cartographie et dynamique de la vĂ©gĂ©tation (1925-2011)

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    Joumine Marsh ; National Park of Ichkeul, Tunisia : floristic diversity, vegetation mapping and dynamics (1925-2011). The vegetation of Joumine Marsh (National Park of Ichkeul, Tunisia) has been studied from 2005 to 2011 with the aims : (1) to characterize the present-day status of the marsh vegetation based on plant inventories and phytosociological surveys, (2) to identify the influence of interannual hydrological changes on the plant distribution, and (3) to reconstruct, on the basis of previous works, the vegetation dynamics over the past 86 years (1925-2011). Results reveal the regression and sometimes the local extinction of the plants of temporary freshwater habitats, and their replacement by halophilous, cultivation-tolerant, footpath and grazing-tolerant species. Such changes express the artificialisation of the marsh. The mid-term dynamics of Joumine Marsh (1925-2011) is characterized by four periods : (1) before the first hydrological developments realized on the Joumine Wady in 1948, the marsh was dominated by the helophytic formation of Bolboschoenus glaucus and Schoenoplectus litoralis ; (2) between 1948 and the putting into service of the Joumine Dam in 1982/ 83, the helophytic vegetation remained dominant ; (3) between 1982-1983 and the summer 2002, because of an inappropriate management of the reservoir (without freshwater release), the salinity of the marsh has considerably increased, triggering the decline of the hydrophilous vegetation and the expansion of salt scrubs of Sarcocornia fruticosa ; (4) finally, since autumn 2002, occasional releases of freshwater from the Joumine reservoir and the realization of new hydrological developments on the Joumine ditch lead to the inundation and washing of the marsh. These changes have induced the partial replacement of the salt scrubs by renewed helophytic herbaceous formations. This study reveals the significance of the ratio “hydro-hygrophilous plants/halophilous plants” as an indicator of the health of coastal wetlands. This ratio, as a simple tool for helping the management, may be used at the scale of the entire system lake-marsh of Ichkeul.La vĂ©gĂ©tation du marais de Joumine (Parc National de l’Ichkeul, Tunisie) a Ă©tĂ© Ă©tudiĂ©e entre 2005 et 2011 dans les buts : (1) de caractĂ©riser l’état actuel de la vĂ©gĂ©tation du marais sur la base d’inventaires floristiques et de relevĂ©s phytosociologiques, (2) d’identifier l’influence des changements hydrologiques interannuels sur la rĂ©partition de la vĂ©gĂ©tation, et (3) de reconstruire, sur la base de travaux antĂ©rieurs, la dynamique de la vĂ©gĂ©tation sur 86 ans (1925-2011). Les rĂ©sultats rĂ©vĂšlent la rĂ©duction, voire la disparition, des espĂšces infĂ©odĂ©es aux milieux temporaires d’eau douce, et leur remplacement par des espĂšces halophiles, adventices, rudĂ©rales et indicatrices de surpĂąturage. Ces changements dĂ©notent l’artificialisation du marais. La dynamique Ă  moyen terme de la vĂ©gĂ©tation du marais de Joumine (1925-2011) est caractĂ©risĂ©e par quatre pĂ©riodes : (1) avant les premiers amĂ©nagements hydrauliques rĂ©alisĂ©s sur l’oued Joumine en 1948, le marais Ă©tait dominĂ© par la scirpaie Ă  Bolboschoenus glaucus et Schoenoplectus litoralis ; (2) entre 1948 et la mise en service du barrage de Joumine en 1982/ 83, la scirpaie est restĂ©e dominante ; (3) entre 1982-83 et l’étĂ© 2002, sous l’effet d’une gestion inappropriĂ©e du barrage (sans lĂącher d’eau douce), la salinitĂ© du marais a considĂ©rablement augmentĂ©, provoquant le dĂ©clin de la vĂ©gĂ©tation hydro-hygrophile et l’extension de la sansouĂŻre Ă  Sarcocornia fruticosa ; (4) enfin, depuis l’automne 2002, des lĂąchers occasionnels d’eau douce Ă  partir du barrage de Joumine et la rĂ©alisation de nouveaux amĂ©nagements sur le canal de Joumine ont conduit Ă  l’inondation et au lessivage du marais. Ces changements ont entraĂźnĂ© le dĂ©clin de la vĂ©gĂ©tation halophile au profit de la rĂ©gĂ©nĂ©ration de la scirpaie. Cette Ă©tude met en Ă©vidence l’importance du rapport «vĂ©gĂ©tation hydro-hygrophile/ vĂ©gĂ©tation halophile » en tant qu’indicateur de l’état de santĂ© de marais littoraux. Ce rapport, qui apparaĂźt comme un outil simple d’aide Ă  la gestion, peut ĂȘtre exploitĂ© Ă  l’échelle de l’ensemble du systĂšme lac-marais de l’Ichkeul.Ouali Mounira, Daoud-Bouattour Amina, Etteieb Selma, Gammar Amor Mokhtar, Ben Saad-Limam Samia, Ghrabi Gammar Zeineb. Le marais de Joumine, Parc National de l’Ichkeul, Tunisie : diversitĂ© floristique, cartographie et dynamique de la vĂ©gĂ©tation (1925-2011). In: Revue d'Écologie (La Terre et La Vie), tome 69, n°1, 2014. pp. 3-23

    Flore vasculaire rare, endémique et menacée des zones humides de Tunisie

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    Summary. — Rare, endemic and threatened vascular flora of Tunisian wetlands. — Tunisian wetlands harbour a large floristic richness, estimated at 407 species representing 228 genera and 75 families. This flora comprises species strictly limited to wetlands, and species originating from surrounding lands. It is characterized by a big proportion of rare and/ or threatened taxa (~ 29 %). Kroumirie is the richest region, with 290 taxa among which 54 are considered as very rare, rare or infrequent, because of their limited distribution area, generally located in frail or degraded ecosystems. The preservation of this exceptional biodiversity, threatened on short term, implies the urgent development of scientific investigations and adapted protection measures.RĂ©sumĂ©. — Les zones humides de Tunisie prĂ©sentent une grande richesse floristique, Ă©valuĂ©e Ă  407 espĂšces reprĂ©sentant 228 genres et 75 familles. Ces espĂšces sont, soit strictement infĂ©odĂ©es aux zones humides, soit transgressives des milieux terrestres. Cette flore est caractĂ©risĂ©e par une forte proportion des taxons rares et/ ou menacĂ©s (~ 29 %). La Kroumirie est la rĂ©gion la plus riche, avec 290 taxons dont 54 sont considĂ©rĂ©s comme trĂšs rares, rares ou peu rĂ©pandus, en raison de leur rĂ©partition rĂ©duite et gĂ©nĂ©ralement situĂ©e au niveau d’écosystĂšmes trĂšs fragiles ou dĂ©gradĂ©s. La prĂ©servation de cette biodiversitĂ© exceptionnelle et menacĂ©e Ă  court terme nĂ©cessite la mise en place urgente d’études scientifiques et de mesures de protection appropriĂ©es.Ghrabi Gammar Zeineb, Daoud-Bouattour Amina, Ferchichi Hafawa, Gammar Amor Mokhtar, Muller Serge, Rhazi LaĂŻla, Limam-Ben Saad Semia. Flore vasculaire rare, endĂ©mique et menacĂ©e des zones humides de Tunisie. In: Revue d'Écologie (La Terre et La Vie), tome 64, n°1, 2009. pp. 19-40
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