27 research outputs found

    Factors Influencing Adoption of Rangeland Rehabilitation Technologies by Agro-Pastoralists in the Arabian Peninsula: Evidence from Analysis in Saudi Arabia and Qatar

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    Rangelands are the main land use in the Arabian Peninsula and cover about 50% of total area. They are under continuous heavy grazing pressure due to underlying social and economic causes as well as institutional effects. ICARDA in collaboration with the National Agricultural Research Systems (NARS) has developed and introduced different rehabilitation techniques including resting, planting native range species and water harvesting in different countries of the AP such as Kuwait, Qatar, Saudi Arabia (KSA) and Yemen. However, the adoption of these techniques by end users was not evaluated. In this context, a research has been conducted in Saudi Arabia and Qatar to determine the factors affecting the speed of adoption and identify the main constraints affecting the adoption level and the dissemination for these rehabilitation techniques with special focus on perceived perceptions of the research and extension (R&E) systems on the impact of the characteristics of these technologies on their adoption level. To meet these objectives, the Adoption and Diffusion Outcome Prediction Tool (ADOPT) and the Likert-scale approach have been implemented and the qualitative data were gathered through two focus group discussion, respectively. The empirical findings revealed a significant difference between KSA and Qatar on the predicted peak of adoption of this technological package (planting native range species and water harvesting). Although the predicted years to peak such adoption are around 18 years, the peak of adoption is expected to be 92% for KSA and 11% for Qatar. This is mainly due to the fact that this technological package is newly getting adopted in Qatar. This predicted peak remains very low even during the first five and ten years for the case of Qatar. The main factors constraining the adoption of these rehabilitation technologies and therefore its dissemination are the complexity of the innovation, its trialability, the need to develop substantial new skills and knowledge to use the innovation, and the up-front cost of the investment relative to the potential annual benefit from adopting this technological package

    Impact of grazing on the floristic diversity of arid rangelands in South Tunisia

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    If the effects of grazing on plant diversity have been extensively studied in a wide range of ecosystems, effects of controlled grazing are still largely unknown. Species diversity indices are useful indicators of the sustainability of collective rangelands in southern Tunisia. In order to determine an optimal management method of arid rangelands with high heritage value, we examined the respective effects of continuous grazing, moderate grazing and rest on the plant community’s diversity. We compared diversity indices of the vegetation for three levels of grazing pressure (null, moderate and heavy) in the collective rangelands dominated by Gymnocarpos decander, Hammada schmittiana, Stipagrostis pungens and Anthyllis sericea of Dhahars in the south-eastern region of Tataouine (Tunisia). Species richness and Simpson’s diversity tended to decrease with increased grazing pressure, but the difference was not significant between ungrazed and moderately grazed rangelands. By contrast, species evenness tended to increase with grazing pressure. Diversity and vegetation biological spectrum were only slightly affected by controlled grazing. This study demonstrates the value of this management practice for biodiversity conservationSi les effets du pâturage sur la diversité floristique ont été largement étudiés sur une large gamme d'écosystèmes, les effets du pâturage contrôlé restent encore très peu connus. Les indices de diversité spécifique sont des indicateurs utiles pour l'évaluation de la durabilité des parcours collectifs. En vue de déterminer un mode de gestion optimal des parcours arides à forte valeur patrimoniale du sud tunisien, nous avons examiné les effets respectifs du pâturage continu, modéré et de mise en repos sur la diversité des communautés végétales. Les indices de diversité de la végétation ont été comparés en fonction de trois niveaux de pression pastorale (nulle, modérée, forte) sur des parcours communautaires à Gymnocarpos decander, Hammada schmittiana, Stipagrostis pungens et Anthyllis sericea des Dhahars de la région au sud-est de Tataouine (Tunisie). La richesse spécifique et la diversité de Simpson tendent à diminuer quand la pression de pâturage est plus élevée, mais la différence n'est pas significative entre les parcours non ou modérément pâturés. L'équitabilité tend par contre à augmenter avec l'augmentation de la charge animale. La diversité spécifique et le spectre biologique de la végétation n'ont été que peu affectés par le pâturage contrôlé. Cette étude montre donc l'intérêt de ce type de gestion pour la conservation de la biodiversité

    Effects of natural long storage duration on seeds germinative response of Argyrolobium uniflorum (Decne.) Jaub. & Spach

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    Little is known about the effect of seed natural long storage on the germination capacity of vascular plant species particularly those used in restoration programs.  In the current paper, we aimed to study the effect of different seed storage durations (from 3 months to 22 years) on the germination of Argyrolobium uniflorum (Decne.) Jaub. & Spach, herbaceous legume of high pastoral value indigenous to the Mediterranean Basin. In this paper, we found that the seeds scarification, hasten germination capacity of scarified seeds (SS) to almost 80%. The seed germination is maintained for 14 years at the level of 78 to 60% and then decreases. Also, other measured parameters of water content, electric conductivity, seedling lengths and MGT were also modified along seeds age. The duration of storage affects the germination performance of Argyrolobium uniflorum seeds which decreases after approximately one decade and half which give us an idea about the longevity of soil seeds bank of this species

    Object-based assessment of tree attributes of Acacia tortilis in Bou-Hedma, Tunisia

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    Acacia tortilis subsp. raddiana represents the most important woody species in the pre-Saharan zone. It is the only forest tree persisting on the edge of the desert. Due to tree/environment interactions, canopy sub-habitats arise, enabling an increased storage of soil water, soil nutrients and soil oxygen. Depending on their density, they can also reduce erosion and reverse desertification. Soil erosion and desertification are the main problems faced by the UNESCO Biosphere Reserve in South-Tunisia (Bou-Hedma National Park). The restoration of the original woodland cover to combat desertification (particularly) by afforestation and reforestation of Acacia tortilis goes hand in hand with a climate change in the Biosphere Reserve, also influencing rural population outside the Biosphere Reserve. In order to study the different effects of woodland restoration in Bou-Hedma, the number of Acacia trees and their attributes have to be known. High resolution satellite imagery (GeoEye-1), was used with a GEOBIA approach. Field measurement of bole diameter, crown diameter and tree height were collected at > 400 locations. After segmentation, correlations with > 200 object features and tree attributes were calculated. For crown diameter and tree height, high correlations were observed with the features area and GLCM Entropy Layer 4 (90 degrees). Relations between these features and measured tree attributes were modeled, resulting in RMSE values of resp. 1.47 m and 1.62 m for crown diameter estimation and 0.92 m for tree height. The results show that a GEOBIA working strategy is suitable for estimating tree attributes in open forests in semi-arid regions

    Sustainable Rangeland Management Toolkit for Resilient Pastoral Systems

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    This toolkit is a collection of adaptable site-specific Sustainable Rangeland Management practices that developed to manage rangelands in the dry areas, achieving a neutral level of degradation and offering a strong potential to restore degraded rangelands. It is a result of collaboration among three institutions – the International Livestock Research Institute (ILRI), the International Center for Agriculture Research in the Dry Areas (ICARDA) and the International Union for Conservation of Nature (IUCN). The flexibility of the SRM toolbox within different agroecological scenarios raises its potential for upscale across the dry areas

    Variations de la diversité floristique en fonction du mode de gestion des parcours arides de la Tunisie méridionale

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    The evolution of plant diversity according to three levels of pastoral pressure (null, moderate and strong) was studied in the collective rangelands of Dhahars in the south-eastern region of Tataouine (Tunisia). The study was carried out in the saharian zones in rangelands of Gymnocarpos decander, Hammada schmittiana, Stipagrostis pungens, and Anthyllis sericea. Under moderate grazing species diversity is only slightly affected. The study suggested that moderate grazing might be an effective means to maintain the diversity of the Saharan rangelands because overgrazing resulted in deterioration of this vital resource, which dropped more than 3/4.La variation de la diversité spécifique en fonction de trois niveaux de pression pastorale (nulle, modérée, forte) a été étudiée sur des parcours collectifs des Dhahars de la région au sud-est de Tataouine. L’étude a été conduite sur des parcours des zones sahariennes à Gymnocarpos decander, Hammada schmittiana, Stipagrostis pungens et Anthyllis sericea. Sous une pression pastorale modérée, la diversité spécifique n’est que très légèrement affectée. Ces résultats suggèrent que le pâturage modéré est un moyen efficace de maintenir la diversité des parcours sahariens puisque le surpâturage a entraîné une détérioration de cette ressource vitale, qui régresse de plus de trois quarts.Gamoun Mouldi, Ouled Belgacem Azaiez, Hanchi Belgacem, Neffati Mohamed. Variations de la diversité floristique en fonction du mode de gestion des parcours arides de la Tunisie méridionale. In: Ecologia mediterranea, tome 37 n°2, 2011. Numéro spécial, 7e conférence européenne SER en écologie de la restauration, 23-27 août 2010, Avignon, France. pp. 33-44

    A preliminary overview of the effects of seasonal drought and animal pressure around watering points on plant species using adaptative strategy analyses in the Tunisian arid zone

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    Throughout the arid environment, vegetation is submitted to many stresses (edaphic and climatic) and to human disturbances (overgrazing, cultivation, wood cutting, etc.). In order to minimize the effect of these constraints, plant species have developped several adaptative strategies. We study the effects of seasonal drought and overgrazing around watering points on these strategies. For this purpose we employ the point intercept method on four transects around three wells in southern Tunisia. The main results are : (1) The covers of chamaephytes, hemicryptophytes and therophytes increase in spring ; (2) hemicryptophyte and chamaephyte covers increase with increasing distance from wells while the cover of therophytes do not ; (3) in spring, arido-passive and aridoactive species covers are more important ; (4) arido-active species cover increases with increasing distance from wells while the arido-passive species cover is not influenced by this grazing gradient ; (5) The covers of CRS and RS plants increase in spring and (6) CS, CRS and S covers increase with increasing distance from wells while the RS cover is not influenced by this gradient.Au sein des zones arides, la végétation naturelle est soumise à l’action de plusieurs stress (édaphique et climatique) ainsi que des perturbations anthropiques (surpâturage, mise en culture, éradication des ligneux…). Dans le but de minimiser l’effet de ces contraintes, les espèces végétales développent plusieurs stratégies adaptatives. Nous étudions les effets de la sécheresse saisonnière et du surpâturage autour des points d’eau sur les espèces végétales et leurs stratégies adaptatives. Pour atteindre cet objectif, nous employons la méthode des points quadrats au sein de quatre transects rayonnant autour de trois points d’eau situés au sud tunisien. Les principaux résultats sont : (1) les recouvrements des chaméphytes, des hémicryptophytes et des thérophytes augmentent au cours du printemps ; (2) les recouvrements des chaméphytes et des hémicryptophytes augmentent en fonction des distances par rapport aux puits alors que celui des thérophytes ne varie pas ; (3) au cours du printemps, les recouvrements des arido-passives et des arido-actives sont plus importants ; (4) le recouvrement des aridoactives augmente avec la distance par rapport aux puits mais celui des arido-passive ne varie pas ; (5) le recouvrement des CRS et celui des RS sont plus importants au cours du printemps et (6) les recouvrements des CS, des CRS et des S augmentent avec la distance par rapport aux puits à l’exception de celui des RS.Tarhouni Mohamed, Ouled Belgacem Azaiez, Henchi Belgacem, Neffati Mohamed. A preliminary overview of the effects of seasonal drought and animal pressure around watering points on plant species using adaptative strategy analyses in the Tunisian arid zone. In: Ecologia mediterranea, tome 32,2006. pp. 39-48

    Diversity of desert rangelands of Tunisia

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    Plants are important components of any rangeland. However, the importance of desert rangeland plant diversity has often been underestimated. It has been argued that desert rangelands of Tunisia in good ecological condition provide more services than those in poor ecological condition. This is because rangelands in good condition support a more diverse mixture of vegetation with many benefits, such as forage for livestock and medicinal plants.Nearly one-quarter of Tunisia, covering about 5.5 million hectares, are rangelands, of which 87% are located in the arid and desert areas (45% and 42%, respectively). Here, we provide a brief review of the floristic richness of desert rangelands of Tunisia. Approximately 135 species are specific to desert rangelands. The predominant families are Asteraceae, Poaceae, Brassicaceae, Chenopodiaceae, and Fabaceae. These represent approximately 50% of Tunisian desert flora. Keywords: Vegetation, Dryland, Species richnes
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