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Slaheddine Selmi - One of the best experts on this subject based on the ideXlab platform.

  • diversity prevalence and host specificity of avian parasites in southern tunisian Oases
    Parasitology, 2017
    Co-Authors: Tasnim Ayadi, Slaheddine Selmi, Thierry Boulinier, Abdessalem Hammouda, Sandra Reis, Claire Loiseau
    Abstract:

    Oases are semi-natural woodlots surrounded by an inhospitable desert environment. This insular-like habitat system is known to support a mixture of sedentary and migratory bird species originating from different areas. However, little is known about the interactions between these birds and parasites. In this study, we investigated the diversity, prevalence and host specificity of avian haemosporidian parasites in southern Tunisian Oases in two sedentary and common bird species, the laughing dove Spilopelia senegalensis and hybrid sparrow Passer domesticus × hispaniolensis , in six sites that differ regarding vegetation structure and distance to the coast. Two new Haemoproteus lineages, related to other Haemoproteus transmitted by biting midges, were detected in doves. With regard to sparrows, all detected parasites have previously been reported in other sparrow populations, except for one new Haemoproteus lineage. Our results also showed that densely vegetated sites were characterized by the higher prevalence of Plasmodium but a lower prevalence of Haemoproteus compared with less-vegetated sites. This is the first study aiming to explore avian parasites in the oasis habitat. Gathering data on a larger sample of Oases with different sizes and isolation levels will be the next step to better understand factors shaping the transmission dynamics of avian parasites in such ecosystems.

  • Determinants of distribution, abundance and reproductive success of the Common Blackbird (Turdus merula) in southern Tunisian Oases
    Ostrich, 2007
    Co-Authors: Slaheddine Selmi
    Abstract:

    The Common Blackbird has extended its geographic range in Tunisia recently and colonised Oases in the southern part of the country. Here, I examine the role of oasis spatial distribution and local vegetation structure in shaping Blackbird distribution and abundance patterns in the oasis system. I also provide preliminary results on the breeding biology of Blackbirds in their new habitat. Blackbird occurrence in a given oasis was mainly dependent on its presence in neighbouring Oases, while vegetation structure did not predict Blackbird occurrence. Within occupied Oases, local abundance was associated with the diversity and abundance of fruit trees and herbaceous plants. This suggests that dispersal and colonisation from nearby occupied Oases play an important role in shaping oasis occupancy pattern, while local vegetation structure determines the abundance of locally established populations. The abundance of trees affects nest site availability and breeding success, based on observations at two Oases. Bla...

  • distribution and abundance patterns of a newly colonizing species in tunisian Oases the common blackbird turdus merula
    Ibis, 2003
    Co-Authors: Slaheddine Selmi, Thierry Boulinier, Bruno Faivre
    Abstract:

    We investigated distribution and abundance patterns of a recently arrived species in the Oases of southern Tunisia: the Common Blackbird Turdus merula. In this system, we expected that the vegetation structure and geographical locations of Oases would have played an important part in shaping the patterns of oasis occupancy and local abundance. Using data collected at 53 Oases during two breeding seasons, we found that Blackbird occurrence in a given oasis depended mainly on its presence at neighbouring Oases. However, vegetation structure did not prove to be a relevant predictor of Blackbird occurrence. Within occupied Oases, local abundance was associated with vegetation structure, namely with the diversity and abundance of the two lowest vegetation layers: fruit trees and herbaceous plants. The presence of Blackbirds at neighbouring Oases was not found to account for local abundance. Overall, our results suggest that the distribution and abundance of this newly colonizing species in the southern Tunisian oasis system are influenced by processes acting at two different spatial scales. Landscape-scale processes (i.e. dispersal and colonization from nearby occupied Oases) are likely to play an important role in shaping the pattern of oasis occupancy, whereas local-scale factors seem to be more relevant in determining the abundance of locally established populations.

  • breeding bird communities in southern tunisian Oases the importance of traditional agricultural practices for bird diversity in a semi natural system
    Biological Conservation, 2003
    Co-Authors: Slaheddine Selmi, Thierry Boulinier
    Abstract:

    We investigated the diversity of breeding bird communities in 53 Oases in southern Tunisia. In particular, we examined the similarity of bird communities among Oases in relation to vegetation structure and geographic location. We found that Oases close to each other supported similar bird communities, suggesting that the spatial distribution of Oases has played an important role in shaping local communities. Accounting for oasis location, bird richness was related to oasis size and to vegetation traits, namely to the diversity of trees and herbaceous plants. Oases within which traditional practices are used to diversify the agricultural products were found to provide more suitable habitat conditions for birds than modern plantations created to maximize the production of dates. Traditional Oases represent semi-natural habitats within which traditional human activities may be essential for maintaining their biodiversity, and we think that more attention to the conservation of these systems is to be paid.

Thierry Boulinier - One of the best experts on this subject based on the ideXlab platform.

  • diversity prevalence and host specificity of avian parasites in southern tunisian Oases
    Parasitology, 2017
    Co-Authors: Tasnim Ayadi, Slaheddine Selmi, Thierry Boulinier, Abdessalem Hammouda, Sandra Reis, Claire Loiseau
    Abstract:

    Oases are semi-natural woodlots surrounded by an inhospitable desert environment. This insular-like habitat system is known to support a mixture of sedentary and migratory bird species originating from different areas. However, little is known about the interactions between these birds and parasites. In this study, we investigated the diversity, prevalence and host specificity of avian haemosporidian parasites in southern Tunisian Oases in two sedentary and common bird species, the laughing dove Spilopelia senegalensis and hybrid sparrow Passer domesticus × hispaniolensis , in six sites that differ regarding vegetation structure and distance to the coast. Two new Haemoproteus lineages, related to other Haemoproteus transmitted by biting midges, were detected in doves. With regard to sparrows, all detected parasites have previously been reported in other sparrow populations, except for one new Haemoproteus lineage. Our results also showed that densely vegetated sites were characterized by the higher prevalence of Plasmodium but a lower prevalence of Haemoproteus compared with less-vegetated sites. This is the first study aiming to explore avian parasites in the oasis habitat. Gathering data on a larger sample of Oases with different sizes and isolation levels will be the next step to better understand factors shaping the transmission dynamics of avian parasites in such ecosystems.

  • distribution and abundance patterns of a newly colonizing species in tunisian Oases the common blackbird turdus merula
    Ibis, 2003
    Co-Authors: Slaheddine Selmi, Thierry Boulinier, Bruno Faivre
    Abstract:

    We investigated distribution and abundance patterns of a recently arrived species in the Oases of southern Tunisia: the Common Blackbird Turdus merula. In this system, we expected that the vegetation structure and geographical locations of Oases would have played an important part in shaping the patterns of oasis occupancy and local abundance. Using data collected at 53 Oases during two breeding seasons, we found that Blackbird occurrence in a given oasis depended mainly on its presence at neighbouring Oases. However, vegetation structure did not prove to be a relevant predictor of Blackbird occurrence. Within occupied Oases, local abundance was associated with vegetation structure, namely with the diversity and abundance of the two lowest vegetation layers: fruit trees and herbaceous plants. The presence of Blackbirds at neighbouring Oases was not found to account for local abundance. Overall, our results suggest that the distribution and abundance of this newly colonizing species in the southern Tunisian oasis system are influenced by processes acting at two different spatial scales. Landscape-scale processes (i.e. dispersal and colonization from nearby occupied Oases) are likely to play an important role in shaping the pattern of oasis occupancy, whereas local-scale factors seem to be more relevant in determining the abundance of locally established populations.

  • breeding bird communities in southern tunisian Oases the importance of traditional agricultural practices for bird diversity in a semi natural system
    Biological Conservation, 2003
    Co-Authors: Slaheddine Selmi, Thierry Boulinier
    Abstract:

    We investigated the diversity of breeding bird communities in 53 Oases in southern Tunisia. In particular, we examined the similarity of bird communities among Oases in relation to vegetation structure and geographic location. We found that Oases close to each other supported similar bird communities, suggesting that the spatial distribution of Oases has played an important role in shaping local communities. Accounting for oasis location, bird richness was related to oasis size and to vegetation traits, namely to the diversity of trees and herbaceous plants. Oases within which traditional practices are used to diversify the agricultural products were found to provide more suitable habitat conditions for birds than modern plantations created to maximize the production of dates. Traditional Oases represent semi-natural habitats within which traditional human activities may be essential for maintaining their biodiversity, and we think that more attention to the conservation of these systems is to be paid.

Ricardo Rodriguezestrella - One of the best experts on this subject based on the ideXlab platform.

  • islands in the desert for cavity nesting bees and wasps ecology patterns of diversity and conservation at Oases of baja california peninsula
    Ecology and Evolution, 2020
    Co-Authors: Armando Falconbrindis, Ricardo Rodriguezestrella, Maria Luisa Jimenez
    Abstract:

    Aims: The Oases of Baja California Peninsula (BCP) have been proposed as important hotspots of biodiversity that hold an exceptional richness in the middle of desert conditions. We tested the effect of habitat and anthropogenic disturbance on communities of cavity-nesting taxa, with specific emphasis on bees, wasps, and their natural enemies. Methods: In Oases of BCP and desert neighbor environments, trap-nesting taxa were evaluated in response to factors affecting the nest abundance, richness, and community structure. We used statistical models to find correlates of nest abundance and patterns of diversity, as well as ecological analyses to determine the effect of habitat and human disturbance on species diversity and community structure. Results: Solar irradiation, distance to a perennial waterbody and relative humidity influenced the presence of nests, number of brood cells, and parasitism. In general, abundance, species richness, and parasitism were higher in Oases, especially in those with less human disturbance. Bees did not discriminate between Oases and deserts to nest, whereas mud-daubing wasps were more dependent of Oases. The degree of anthropogenic disturbance did not affect the occurrence of parasitism, but it had an adverse effect on the parasitism intensity (number of attacked cells). The community structure was more complex and even in Oases and low-disturbed sites. The similarity between sites did not exceed 30%, and the proportion of shared species between Oases and deserts varied from 2.7% to 26.6%. Main conclusions: The Oases of Baja California are functioning as mesic islands in the desert, each oasis hosting a unique community of cavity-nesting taxa. About 65% of the nests and 50% of species occurred exclusively in the oasis. Thus, cavity-nesting species that depend on mesic conditions could be threatened if the Oases of BCP disappear in the future. Local conditions in the Oases and deserts of the BCP are shaping the community structure. However, large-scale factors such as climate can influence the seasonality and occurrence of species within the community of cavity-nesting dwellers. Since habitat loss and fragmentation can degrade the Oases' functionality, strategies to maintain the ecosystem services of pollination and biological control should be included in the conservation programs of these fragile habitats.

  • the invasive bullfrog lithobates catesbeianus in Oases of baja california sur mexico potential effects in a fragile ecosystem
    Biological Invasions, 2010
    Co-Authors: Victor H Luja, Ricardo Rodriguezestrella
    Abstract:

    The American bullfrog (Lithobates catesbeianus), considered as one of the world’s worst invasive species because of its negative effects on native fauna, has been introduced into over 40 countries in four continents. The invasion status in Mexico is poorly known. The first known record for this species in the Peninsula of Baja California, northwestern Mexico is an individual collected 35 years ago. A great portion of the peninsula is an arid desert where the sources of freshwater are the spring-fed oasis and mountain arroyos that support rare and endemic species closely associated with wetland conditions. Humans, who have introduced alien species, inhabit many of those Oases. The aim of this work was to document the presence of the exotic bullfrog in 40 Oases and mountain arroyos in Baja California Sur state during 2006–2009. Bullfrogs were found in 25% of the Oases sampled; 15% have confirmed records of breeding populations and five Oases are new location records. Our results show a considerable increase (50%) in the number of oasis invaded by bullfrogs in only 8 years. The animal populations of rare or endemic species associated with Oases would be threatened by the arrival of bullfrogs. Actions for their control and eradication are urgently needed.

Bruno Faivre - One of the best experts on this subject based on the ideXlab platform.

  • distribution and abundance patterns of a newly colonizing species in tunisian Oases the common blackbird turdus merula
    Ibis, 2003
    Co-Authors: Slaheddine Selmi, Thierry Boulinier, Bruno Faivre
    Abstract:

    We investigated distribution and abundance patterns of a recently arrived species in the Oases of southern Tunisia: the Common Blackbird Turdus merula. In this system, we expected that the vegetation structure and geographical locations of Oases would have played an important part in shaping the patterns of oasis occupancy and local abundance. Using data collected at 53 Oases during two breeding seasons, we found that Blackbird occurrence in a given oasis depended mainly on its presence at neighbouring Oases. However, vegetation structure did not prove to be a relevant predictor of Blackbird occurrence. Within occupied Oases, local abundance was associated with vegetation structure, namely with the diversity and abundance of the two lowest vegetation layers: fruit trees and herbaceous plants. The presence of Blackbirds at neighbouring Oases was not found to account for local abundance. Overall, our results suggest that the distribution and abundance of this newly colonizing species in the southern Tunisian oasis system are influenced by processes acting at two different spatial scales. Landscape-scale processes (i.e. dispersal and colonization from nearby occupied Oases) are likely to play an important role in shaping the pattern of oasis occupancy, whereas local-scale factors seem to be more relevant in determining the abundance of locally established populations.

Gary Paul Nabhan - One of the best experts on this subject based on the ideXlab platform.

  • Oases of the baja california peninsula as sacred spaces of agrobiodiversity persistence
    Agriculture and Human Values, 2016
    Co-Authors: Rafael De Grenade, Gary Paul Nabhan, Micheline Carino Olvera
    Abstract:

    Oases have served as sacred landscapes and sources of ritual plants in arid regions of the Old and New Worlds. We evaluate the Jesuit mission Oases of the Baja California peninsula (Mexico) for their role in agrobiodiversity persistence, and extend theories of sacred landscapes and biodiversity conservation to agricultural species and practices. Jesuit missionaries on the peninsula (1697–1768) introduced a suite of crops species and agricultural and water management systems that persist in the Oases and have become an integral part of the cultural and religious identity of the peninsula. The sacred landscapes of the Oases are defined by elements of the Jesuit mission systems, such as water capture systems and irrigation canals, stone field borders and terraces, field gardens or huertas, groves of olive trees and date palms, and multi-tiered agroecosystems. Sacred practices—including pilgrimages, religious rites, and Catholic-based community celebrations—depend on the integrated “landscapes” of the Oases and on the ritual use of wild and cultivated oasis plant species. We propose that some, though not all, of the peninsula Oases may be considered as sacred landscapes responsible for maintaining heritage crop species, biodiversity, and traditional farming and foodways practices.

  • baja california peninsula Oases an agro biodiversity of isolation and integration
    Applied Geography, 2013
    Co-Authors: Rafael De Grenade, Gary Paul Nabhan
    Abstract:

    Abstract Agro-biodiversity in the desert Oases of the Baja California peninsula, Mexico is a product of isolation and integration events through time and across peninsular spaces. Historic inventories of agricultural introductions provide a baseline from which to measure Mission-era crop persistence or genetic erosion in fifteen missions established during the Jesuit occupation (1697–1768). These mission-Oases function as a network of interconnected sites supporting cultivated plant assemblages isolated from one another and the Mexican mainland by a desert matrix, by limited transportation infrastructure on the peninsula, and the surrounding sea. Garden surveys of perennial crop species and farmer interviews reveal that Oases serve as refugia of Mission-era crop species and traditional knowledge. Isolation-connectivity analyses indicate that this agro-biodiversity disappears at the extremes: The most isolated and the fully integrated Oases are unable to support heritage perennial crop species and traditional farming systems over long time scales. We describe how phases and processes of isolation and connectivity transform agro-biodiversity composition in this archipelago of peninsula Oases and explore policy applications that could preserve this critical diversity and the rare and available oasis communities.

  • desert Oases as genetic refugia of heritage crops persistence of forgotten fruits in the mission orchards of baja california mexico
    International Journal of Biodiversity and Conservation, 2010
    Co-Authors: Gary Paul Nabhan, Jesus Garcia, Rafael Routson, Kanin J Routson, Micheline Carinoolvera
    Abstract:

    The first introductions of agricultural crops to desert Oases of Baja California, Mexico were initiated by Jesuit missionaries between 1697 and 1768 and historic records from these Jesuits provided a detailed benchmark by which temporal changes in agro-biodiversity can be measured. Longitudinal studies at the agricultural Oases on the Baja California peninsula of Mexico can help determine whether such isolated “islands” of cultivation function as refugia or de facto reserves for in situ conservation of eighteen perennial species introduced by Jesuits. We compared survivorship of these historically introduced perennials at nine Oases and determined that at least fifteen of the original eighteen Mission-era introductions of perennial species persist at these Baja California Oases and one additional species persists on the peninsula outside of its original historic context. Despite this level of overall persistence, no species is cultivated in all nine Oases. The archipelago of cultivated Oases in Baja California should be considered as an aggregate worthy of conservation investments, rather than assuming that any single oasis is sufficient to maintain all historic varieties in the future. We use an analysis of the “forgotten fruits” of Baja California’s missions and ranchos to propose that the theory of island biogeography may be applicable to conservation planning for agro-biodiversity, as it has been for wild biodiversity nested in isolated habitats.