Katia Diadema - Academia.edu (original) (raw)

Papers by Katia Diadema

Authorea (Authorea), Oct 5, 2021

Intense research efforts on phylogeography over the last two decades uncovered major biogeographi... more Intense research efforts on phylogeography over the last two decades uncovered major biogeographical trends and renewed our understandings of plant domestication in the Mediterranean. We aim to investigate the evolutionary history and the origin of domestication of the carob tree that has been cultivated for millennia for food and fodder. We used >1000 microsatellite genotypes to identify carob evolutionary units (CEUs) based on genetic diversity structure and geography. We investigated genome-wide diversity and evolutionary patterns of the CEUs with 3557 SNPs generated by restriction-site associated DNA sequencing (RADseq). The 56 populations sampled across the Mediterranean basin, classified as natural, semi-natural or cultivated, were examined. Although, RADseq data are consistent with previous studies identifying a strong West-to-East genetic structure and considerable admixture in some geographic parts, we reconstructed a new phylogeographic scenario with two migration routes occurring from a single refugium likely located in South-Western Morocco. Our results do not favour the regionally bound or single origin of domestication. Indeed, our findings support a cultivation model of locally selected wild genotypes, albeit punctuated by long-distance westward dispersals of domesticated varieties by humans, concomitant with major cultural waves by Romans and Arabs in the regions of dispersal. Ex-situ efforts to preserve carob genetic resources should prioritize accessions from both western and eastern populations, with emphasis on the most differentiated CEUs situated in South-Western Morocco, South Spain and Eastern Mediterranean. Our study underscores the relevance of natural and seminatural habitats of Mediterranean forests and their refugia in the conservation efforts of tree crops.

ABSTRACT RéSUMé : Cette étude dresse le bilan de la flore vasculaire de l'île Saint‑Honor... more ABSTRACT RéSUMé : Cette étude dresse le bilan de la flore vasculaire de l'île Saint‑Honorat (archipel de Lérins, Alpes‑Maritimes, France) suite aux prospections printanières de 2013 et 2014 engagées grâce à l'Initiative PIM (Petites îles de Méditerranée). Ces prospections ont permis d'inventorier 280 taxons (espèces et sous‑espèces) indi‑ gènes ou naturalisés, dont 80 n'avaient jamais été signalés sur l'île. La richesse floristique totale cumulée est égale à 305 taxons indigènes, dont 257 taxons actuellement présents (données postérieures à l'an 2000) ; 33 végétaux non indigènes et naturalisés ont été aussi mentionnés sur l'île. La présence de 13 espèces végétales rares est discutée et la liste des différents types de végétation est fournie. Enfin, l'analyse des principaux impacts sur la flore et la végétation conduit à proposer certaines modalités de gestion en faveur de ce patrimoine végétal insulaire original, encore bien préservé dans sa globalité. MOTS‑CLéS : Alpes maritimes, Initiative PIM, invasion biologique, inventaire floristique, impacts humains, petite île de Méditerranée, végétaux rares. ABSTRACT: This study concerns the global inventory of the vascular flora of Saint‑Honorat island (Lérins archi‑ pelago, Alpes‑Maritimes, France), as a result of several field trips performed during the springs 2013 and 2014, in relation to the PIM Initiative (Mediterranean small islands initiative). 280 native or alien plant taxa (species and subspecies), whom 80 were never mentioned on the island, were censused during these inventories. The total plant richness corresponds to 305 native taxa whom 257 are currently present; 33 alien plant species are also censused. The occurrence of 13 rare plants is discussed and a complete list of vegetation types is provided. An analysis of main impacts on flora and vegetation allows us to propose some management measures in order to protect this original insular plant assemblage, which is globally still well preserved.

HAL (Le Centre pour la Communication Scientifique Directe), 2015

L'objectif de ce travail consiste a analyser la structure et la dynamique des populations de ... more L'objectif de ce travail consiste a analyser la structure et la dynamique des populations de vegetaux endemiques mediterraneens, selon differentes echelles spatiales et temporelles. Est examinee l'influence des facteurs de biogeographie historique et des facteurs ecologiques actuels. Trois especes endemiques ont ete etudiees. Les donnees phylogeographiques de Gentiana ligustica, suggerent l'existence de plusieurs microrefuges et routes de recolonisation. La fragmentation recente des habitats Acis nicaeensis diminue la viabilite des populations, ce qui entraine un vortex d'extinction. Les perturbations telles que le pâturage ovin ou les incendies, d'intensite et de frequence moyennes, favorisent la persistance des populations. Dans un contexte de changement global, il apparait donc necessaire d'adopter des strategies de conservation au cas par cas, alliant le maintien des pressions intermediaires de perturbations, la conservation des habitats, ou la prise en compte de l'histoire des populations et de leur variabilite ecogeographique.

Journal of Biogeography, Jul 1, 2009

Aim The aims of this study were to assess the distribution of putative Mediterranean refugia of p... more Aim The aims of this study were to assess the distribution of putative Mediterranean refugia of plants, to compare the locations of refugia and those of regional hotspots of plant biodiversity, and to provide a critical analysis of the Mediterranean refugium paradigm. Furthermore, we consider how biogeographical and genetic results can be combined to guide global conservation strategies. Location The Mediterranean region. Methods We started from a detailed analysis of the scientific literature (1993-2007) in order to identify refugia in the Mediterranean region, based on intraspecific phylogeographical studies of plant species. We used population locations together with gene-pool identity to establish the database, comparing patterns of phylogeographical concordance with the locations of Mediterranean refugia. We then tested the biogeographical congruence between two biodiversity components, namely phylogeographical refugia and regional hotspots. Results We identified 52 refugia in the Mediterranean bioclimatic region and confirmed the role played by the three major peninsulas, with a shared total of 25 refugia. We emphasize the importance of areas that have previously been attributed a lesser role (large Mediterranean islands, North Africa, Turkey, Catalonia). Of the 52 refugia identified, 33 are situated in the western Mediterranean Basin and 19 in the eastern part. The locations of the phylogeographically defined refugia are significantly associated with the 10 regional hotspots of plant biodiversity, with 26 of these refugia (i.e. 50%) occurring within the hotspots. Main conclusions The locations of refugia are determined by complex historical and environmental factors, the cumulative effects of which need to be considered because they have occurred since the Tertiary, rather than solely during the last glacial period. Refugia represent climatically stable areas and constitute a high conservation priority as key areas for the long-term persistence of species and genetic diversity, especially given the threat posed by the extensive environmental change processes operating in the Mediterranean region. The refugia defined here represent 'phylogeographical hotspots'; that is, significant reservoirs of unique genetic diversity favourable to the evolutionary processes of Mediterranean plant species.

HAL (Le Centre pour la Communication Scientifique Directe), Oct 1, 2018

Annexe V : Carte représentant les zones Natura Var. Seuls les tronçons avec leur probabilité de p... more Annexe V : Carte représentant les zones Natura Var. Seuls les tronçons avec leur probabilité de présence de la consoude bulbeuse sont ici représentés. ion de la consoude bulbeuse-CBNMed/IMBE-Octobre 2018 : Carte représentant les zones Natura 2000 dans les sous bassins versants côtiers des Alpes Var. Seuls les tronçons avec leur probabilité de présence de la consoude bulbeuse sont ici représentés. Octobre 2018 Page v 2000 dans les sous bassins versants côtiers des Alpes-Maritimes et du Var. Seuls les tronçons avec leur probabilité de présence de la consoude bulbeuse sont ici représentés. Modélisation de la répartition de la consoude bulbeuse Annexe VI : Carte représentant les zones ZNIEFF bassins versants côtiers des Alpes-Maritimes et du Var. ZNIEFF type I : secteurs de grand intérêt biologique ou écologique ; ZNIEFF type II : grands ensembles naturels riches et peu mod ion de la consoude bulbeuse-CBNMed/IMBE-Octobre 2018 : Carte représentant les zones ZNIEFF (Zones d'intérêt écologique faunistique et floristique) Maritimes et du Var. ZNIEFF type I : secteurs de grand intérêt biologique ou écologique ; ZNIEFF type II : grands ensembles naturels riches et peu modifiés, offrant des potentialités biologiques importantes. Octobre 2018 Page vi (Zones d'intérêt écologique faunistique et floristique) dans les sous ifiés, offrant des potentialités biologiques importantes.

Biodiversity and Conservation, Jul 23, 2019

Hierarchisation and prioritisation methods represent a crucial step to determine priorities and i... more Hierarchisation and prioritisation methods represent a crucial step to determine priorities and implement actions in conservation biology: they are required to determine how to allocate available resources to the different components of biodiversity. However, they are very heterogeneous in terms of targets and goals. The main differences are presented with a focus on hierarchisation methods targeting species. This paper reviews 40 studies using 24 different point-scoring or rule-based methods aiming to determine conservation concerns for species. Only the hierarchisation methods targeting species were compared and their differences where highlighted in terms of study area, taxa, criteria assessment and summa-risation. Then six different studies using the same hierarchisation method for species were compared as well. This study enables to analyse the different existing methods in order to perform more relevant methodological choices adapted to the objective and the context of each selection process. A consistent framework is designed to help managers to choose an appropriate method using welldefined goals, study areas and taxonomic targets, and take into account data availability.

Annales de géographie, Oct 1, 2006

Distribution électronique Cairn.info pour Armand Colin. Distribution électronique Cairn.info pour... more Distribution électronique Cairn.info pour Armand Colin. Distribution électronique Cairn.info pour Armand Colin. La reproduction ou représentation de cet article, notamment par photocopie, n'est autorisée que dans les limites des conditions générales d'utilisation du site ou, le cas échéant, des conditions générales de la licence souscrite par votre établissement. Toute autre reproduction ou représentation, en tout ou partie, sous quelque forme et de quelque manière que ce soit, est interdite sauf accord préalable et écrit de l'éditeur, en dehors des cas prévus par la législation en vigueur en France. Il est précisé que son stockage dans une base de données est également interdit. Article disponible en ligne à l'adresse Article disponible en ligne à l'adresse https://www.cairn.info/revue-annales-de-geographie-2006-5-page-618.htm Découvrir le sommaire de ce numéro, suivre la revue par email, s'abonner... Flashez ce QR Code pour accéder à la page de ce numéro sur Cairn.info.

Comptes Rendus Biologies, Sep 1, 2007

We examine the effects of fire and/or surrounding vegetation cover on demographic stage densities... more We examine the effects of fire and/or surrounding vegetation cover on demographic stage densities and plant performance for a rare endemic geophyte, Acis nicaeensis (Alliaceae), in Mediterranean xerophytic grasslands of the 'Alpes-Maritimes' French 'département', through sampling plots in unburned and burned treatments. Fire increases density of flowering individuals and seedling emergence, as well as clump densities and number of individuals per clump, per limiting vegetation height and cover, and increasing bare soil cover. In contrast, fire has no effect on reproductive success. Nevertheless, two growing seasons after fire, all parameters of demographic stages and plant performance do not significantly differ between the two treatments. Small-scale fire is beneficial for the regeneration of this threatened geophyte at a short-time scale. In this context, a conservation planning with small and controlled fires could maintain the regeneration window for populations of rare Mediterranean geophytes. To cite this article:

Annales de géographie, 2006

La place de l’Homme dans l’environnement méditerranéen apparaît plus que jamais comme déterminant... more La place de l’Homme dans l’environnement méditerranéen apparaît plus que jamais comme déterminante, puisque ses impacts et ses choix de gestion déterminent le maintien de la forte biodiversité du bassin méditerranéen. Constitué de 10 hotspots régionaux et une cinquantaine de zones refuges, la région méditerranéenne est fragilisée par la rapidité et l’ampleur des changements environnementaux en cours ou prévus à court terme. À une échelle plus fine, le hotspot régional des Alpes maritimes, représente le plus important centre d’endémisme de l’arc alpin, mais il subit depuis ces dernières décennies des mutations environnementales drastiques. Les confrontations effectuées entre la localisation des zones refuges et celle des territoires fortement anthropisés montrent que les refuges représentent des territoires parmi les plus menacés par l’anthropisation, car ils sont soumis à des pressions démographiques supérieures à la moyenne. Ce constat, particulièrement net à l’échelle du bassin méditerranéen, est un peu atténué à une échelle inférieure, celle des Alpes maritimes. Ainsi, face à l’ampleur et à la croissance des menaces anthropiques sur la biodiversité méditerranéenne, il est nécessaire de mettre en place rapidement une politique intégrative de conservation qui considère en priorité ces zones refuges.

Molecular Phylogenetics and Evolution, 2014

The intraspecific genetic variability of siliceous and calcareous Gentiana species is shaped by c... more The intraspecific genetic variability of siliceous and calcareous Gentiana species is shaped by contrasting demographic and re-colonization processes, Molecular Phylogenetics and Evolution (2013),

HAL (Le Centre pour la Communication Scientifique Directe), Sep 2, 2007

International audienc

HAL (Le Centre pour la Communication Scientifique Directe), Sep 10, 2007

International audienc

Journal for Nature Conservation, Jun 1, 2021

Erosion of natural habitats due to urban sprawl constitutes a major threat to biodiversity. The d... more Erosion of natural habitats due to urban sprawl constitutes a major threat to biodiversity. The development of the Plant Micro-Reserve (PMR) is an efficient concept for the in situ conservation of rare plants with narrow ecological niche and threatened by human impacts. We provide a framework for initiating site selection of PMRs, including evolutionary and ecological uniqueness. The proposed cross-analysis is based on (i) the estimate of population vulnerability, (ii) the contribution of each population to the evolutionary originality of the species by designating conservation units, and (iii) the gap analysis of the current protection status of the populations. As a case study, we apply this framework to the Nice Snowflake Acis nicaeensis, a narrow Mediterranean endemic plant of the French-Italian Riviera which, being caught in the turmoil of urban sprawl, is threatened by tremendous anthropogenic pressures. On the basis of historical data (past land-use and herbarium data) we show that over the last 150 years, the impact of urbanization has been severe for 70 % of the populations and has caused the disappearance of at least 11 of them, i.e. 20 % of the known populations. Similar levels of urban sprawl are observed between the most vulnerable and already extinct populations. In this context of biodiversity decline, our cross-analysis highlights that two of the five conservation units call for a rapid setting up of PMRs because of their high originality and their great risk of extinction: one unit including the populations of the Principality of Monaco and one unit that includes the populations of Nice and its surroundings. This study demonstrates the importance of integrating population vulnerability and conservation units. In a context of huge urbanization our approach makes a clear case for the design of PMRs.

Annales de géographie, 2006

Man’s role appears to be central in the future of the Mediterranean environment, because his impa... more Man’s role appears to be central in the future of the Mediterranean environment, because his impact and management choices are responsible for the persistence of this high biodiversity in the Mediterranean basin. With 10 regional hotspots and 50 plant biodiversity refuge areas, the Mediterranean region is threatened by the quickness and the severity of the current and forecasted environmental changes. More precisely, the Maritime Alps regional hotspot constitutes the most important endemic center of the whole Alps region, but it has been subjected to drastic environmental transformations for the last decades. The comparisons between the distribution of refuges and human threats exhibit similar spatial patterns, both at the Mediterranean region scale and, to a lesser extent, at the Maritime Alps hotspot. Refuge areas constitute some of the most threatened territories due to a higher than average demographic pressure. This observation which is very clear at the level of the Mediterranean basin is slightly mitigated at the lower scale, the Maritime Alps. Thus, facing the increasing threats on the Mediterranean biodiversity, it's essential to quickly undertake an integrative conservation framework at the Mediterranean scale with a prioritization toward refuge areas.

Journal for Nature Conservation

Biodiversity and Conservation, Nov 4, 2016

Current biodiversity patterns are a temporary state in a continuum of ecological and evolutionary... more Current biodiversity patterns are a temporary state in a continuum of ecological and evolutionary changes. Conservation policies must incorporate this dynamic to ensure the long-term conservation of biodiversity which is particularly challenging in a context of extreme urbanization. An original approach, rarely used for plant conservation, is to define conservation units to set conservation priorities within species by combining ecological and evolutionary divergences. In the Maritime Alps (southern France), the ecological and evolutionary divergences between the populations of Acis nicaeensis has allowed us the determination of conservation units of this endemic plant threatened by severe urbanization and land-use changes. Phylogeographical data (cpDNA haplotype) were considered as a proxy for evolutionary legacy, and ecological data (multivariate analysis of habitat) were used as a proxy for ecological distinctiveness. Our goal was to explore the potential of this approach to assess vulnerability and set conservation priorities for narrow endemic species in the context of conflict between biodiversity and human activities. The results highlight five different conservation units within A. nicaeensis distribution. Genetic and ecological divergences are present at fine-scale. This pattern is highly endangered by urbanisation. This study highlights the vulnerability of conservation units near the coast whose Communicated by Daniel Sanchez Mata.

Authorea (Authorea), Oct 5, 2021

Intense research efforts on phylogeography over the last two decades uncovered major biogeographi... more Intense research efforts on phylogeography over the last two decades uncovered major biogeographical trends and renewed our understandings of plant domestication in the Mediterranean. We aim to investigate the evolutionary history and the origin of domestication of the carob tree that has been cultivated for millennia for food and fodder. We used >1000 microsatellite genotypes to identify carob evolutionary units (CEUs) based on genetic diversity structure and geography. We investigated genome-wide diversity and evolutionary patterns of the CEUs with 3557 SNPs generated by restriction-site associated DNA sequencing (RADseq). The 56 populations sampled across the Mediterranean basin, classified as natural, semi-natural or cultivated, were examined. Although, RADseq data are consistent with previous studies identifying a strong West-to-East genetic structure and considerable admixture in some geographic parts, we reconstructed a new phylogeographic scenario with two migration routes occurring from a single refugium likely located in South-Western Morocco. Our results do not favour the regionally bound or single origin of domestication. Indeed, our findings support a cultivation model of locally selected wild genotypes, albeit punctuated by long-distance westward dispersals of domesticated varieties by humans, concomitant with major cultural waves by Romans and Arabs in the regions of dispersal. Ex-situ efforts to preserve carob genetic resources should prioritize accessions from both western and eastern populations, with emphasis on the most differentiated CEUs situated in South-Western Morocco, South Spain and Eastern Mediterranean. Our study underscores the relevance of natural and seminatural habitats of Mediterranean forests and their refugia in the conservation efforts of tree crops.

ABSTRACT RéSUMé : Cette étude dresse le bilan de la flore vasculaire de l'île Saint‑Honor... more ABSTRACT RéSUMé : Cette étude dresse le bilan de la flore vasculaire de l'île Saint‑Honorat (archipel de Lérins, Alpes‑Maritimes, France) suite aux prospections printanières de 2013 et 2014 engagées grâce à l'Initiative PIM (Petites îles de Méditerranée). Ces prospections ont permis d'inventorier 280 taxons (espèces et sous‑espèces) indi‑ gènes ou naturalisés, dont 80 n'avaient jamais été signalés sur l'île. La richesse floristique totale cumulée est égale à 305 taxons indigènes, dont 257 taxons actuellement présents (données postérieures à l'an 2000) ; 33 végétaux non indigènes et naturalisés ont été aussi mentionnés sur l'île. La présence de 13 espèces végétales rares est discutée et la liste des différents types de végétation est fournie. Enfin, l'analyse des principaux impacts sur la flore et la végétation conduit à proposer certaines modalités de gestion en faveur de ce patrimoine végétal insulaire original, encore bien préservé dans sa globalité. MOTS‑CLéS : Alpes maritimes, Initiative PIM, invasion biologique, inventaire floristique, impacts humains, petite île de Méditerranée, végétaux rares. ABSTRACT: This study concerns the global inventory of the vascular flora of Saint‑Honorat island (Lérins archi‑ pelago, Alpes‑Maritimes, France), as a result of several field trips performed during the springs 2013 and 2014, in relation to the PIM Initiative (Mediterranean small islands initiative). 280 native or alien plant taxa (species and subspecies), whom 80 were never mentioned on the island, were censused during these inventories. The total plant richness corresponds to 305 native taxa whom 257 are currently present; 33 alien plant species are also censused. The occurrence of 13 rare plants is discussed and a complete list of vegetation types is provided. An analysis of main impacts on flora and vegetation allows us to propose some management measures in order to protect this original insular plant assemblage, which is globally still well preserved.

HAL (Le Centre pour la Communication Scientifique Directe), 2015

L'objectif de ce travail consiste a analyser la structure et la dynamique des populations de ... more L'objectif de ce travail consiste a analyser la structure et la dynamique des populations de vegetaux endemiques mediterraneens, selon differentes echelles spatiales et temporelles. Est examinee l'influence des facteurs de biogeographie historique et des facteurs ecologiques actuels. Trois especes endemiques ont ete etudiees. Les donnees phylogeographiques de Gentiana ligustica, suggerent l'existence de plusieurs microrefuges et routes de recolonisation. La fragmentation recente des habitats Acis nicaeensis diminue la viabilite des populations, ce qui entraine un vortex d'extinction. Les perturbations telles que le pâturage ovin ou les incendies, d'intensite et de frequence moyennes, favorisent la persistance des populations. Dans un contexte de changement global, il apparait donc necessaire d'adopter des strategies de conservation au cas par cas, alliant le maintien des pressions intermediaires de perturbations, la conservation des habitats, ou la prise en compte de l'histoire des populations et de leur variabilite ecogeographique.

Journal of Biogeography, Jul 1, 2009

Aim The aims of this study were to assess the distribution of putative Mediterranean refugia of p... more Aim The aims of this study were to assess the distribution of putative Mediterranean refugia of plants, to compare the locations of refugia and those of regional hotspots of plant biodiversity, and to provide a critical analysis of the Mediterranean refugium paradigm. Furthermore, we consider how biogeographical and genetic results can be combined to guide global conservation strategies. Location The Mediterranean region. Methods We started from a detailed analysis of the scientific literature (1993-2007) in order to identify refugia in the Mediterranean region, based on intraspecific phylogeographical studies of plant species. We used population locations together with gene-pool identity to establish the database, comparing patterns of phylogeographical concordance with the locations of Mediterranean refugia. We then tested the biogeographical congruence between two biodiversity components, namely phylogeographical refugia and regional hotspots. Results We identified 52 refugia in the Mediterranean bioclimatic region and confirmed the role played by the three major peninsulas, with a shared total of 25 refugia. We emphasize the importance of areas that have previously been attributed a lesser role (large Mediterranean islands, North Africa, Turkey, Catalonia). Of the 52 refugia identified, 33 are situated in the western Mediterranean Basin and 19 in the eastern part. The locations of the phylogeographically defined refugia are significantly associated with the 10 regional hotspots of plant biodiversity, with 26 of these refugia (i.e. 50%) occurring within the hotspots. Main conclusions The locations of refugia are determined by complex historical and environmental factors, the cumulative effects of which need to be considered because they have occurred since the Tertiary, rather than solely during the last glacial period. Refugia represent climatically stable areas and constitute a high conservation priority as key areas for the long-term persistence of species and genetic diversity, especially given the threat posed by the extensive environmental change processes operating in the Mediterranean region. The refugia defined here represent 'phylogeographical hotspots'; that is, significant reservoirs of unique genetic diversity favourable to the evolutionary processes of Mediterranean plant species.

HAL (Le Centre pour la Communication Scientifique Directe), Oct 1, 2018

Annexe V : Carte représentant les zones Natura Var. Seuls les tronçons avec leur probabilité de p... more Annexe V : Carte représentant les zones Natura Var. Seuls les tronçons avec leur probabilité de présence de la consoude bulbeuse sont ici représentés. ion de la consoude bulbeuse-CBNMed/IMBE-Octobre 2018 : Carte représentant les zones Natura 2000 dans les sous bassins versants côtiers des Alpes Var. Seuls les tronçons avec leur probabilité de présence de la consoude bulbeuse sont ici représentés. Octobre 2018 Page v 2000 dans les sous bassins versants côtiers des Alpes-Maritimes et du Var. Seuls les tronçons avec leur probabilité de présence de la consoude bulbeuse sont ici représentés. Modélisation de la répartition de la consoude bulbeuse Annexe VI : Carte représentant les zones ZNIEFF bassins versants côtiers des Alpes-Maritimes et du Var. ZNIEFF type I : secteurs de grand intérêt biologique ou écologique ; ZNIEFF type II : grands ensembles naturels riches et peu mod ion de la consoude bulbeuse-CBNMed/IMBE-Octobre 2018 : Carte représentant les zones ZNIEFF (Zones d'intérêt écologique faunistique et floristique) Maritimes et du Var. ZNIEFF type I : secteurs de grand intérêt biologique ou écologique ; ZNIEFF type II : grands ensembles naturels riches et peu modifiés, offrant des potentialités biologiques importantes. Octobre 2018 Page vi (Zones d'intérêt écologique faunistique et floristique) dans les sous ifiés, offrant des potentialités biologiques importantes.

Biodiversity and Conservation, Jul 23, 2019

Hierarchisation and prioritisation methods represent a crucial step to determine priorities and i... more Hierarchisation and prioritisation methods represent a crucial step to determine priorities and implement actions in conservation biology: they are required to determine how to allocate available resources to the different components of biodiversity. However, they are very heterogeneous in terms of targets and goals. The main differences are presented with a focus on hierarchisation methods targeting species. This paper reviews 40 studies using 24 different point-scoring or rule-based methods aiming to determine conservation concerns for species. Only the hierarchisation methods targeting species were compared and their differences where highlighted in terms of study area, taxa, criteria assessment and summa-risation. Then six different studies using the same hierarchisation method for species were compared as well. This study enables to analyse the different existing methods in order to perform more relevant methodological choices adapted to the objective and the context of each selection process. A consistent framework is designed to help managers to choose an appropriate method using welldefined goals, study areas and taxonomic targets, and take into account data availability.

Annales de géographie, Oct 1, 2006

Distribution électronique Cairn.info pour Armand Colin. Distribution électronique Cairn.info pour... more Distribution électronique Cairn.info pour Armand Colin. Distribution électronique Cairn.info pour Armand Colin. La reproduction ou représentation de cet article, notamment par photocopie, n'est autorisée que dans les limites des conditions générales d'utilisation du site ou, le cas échéant, des conditions générales de la licence souscrite par votre établissement. Toute autre reproduction ou représentation, en tout ou partie, sous quelque forme et de quelque manière que ce soit, est interdite sauf accord préalable et écrit de l'éditeur, en dehors des cas prévus par la législation en vigueur en France. Il est précisé que son stockage dans une base de données est également interdit. Article disponible en ligne à l'adresse Article disponible en ligne à l'adresse https://www.cairn.info/revue-annales-de-geographie-2006-5-page-618.htm Découvrir le sommaire de ce numéro, suivre la revue par email, s'abonner... Flashez ce QR Code pour accéder à la page de ce numéro sur Cairn.info.

Comptes Rendus Biologies, Sep 1, 2007

We examine the effects of fire and/or surrounding vegetation cover on demographic stage densities... more We examine the effects of fire and/or surrounding vegetation cover on demographic stage densities and plant performance for a rare endemic geophyte, Acis nicaeensis (Alliaceae), in Mediterranean xerophytic grasslands of the 'Alpes-Maritimes' French 'département', through sampling plots in unburned and burned treatments. Fire increases density of flowering individuals and seedling emergence, as well as clump densities and number of individuals per clump, per limiting vegetation height and cover, and increasing bare soil cover. In contrast, fire has no effect on reproductive success. Nevertheless, two growing seasons after fire, all parameters of demographic stages and plant performance do not significantly differ between the two treatments. Small-scale fire is beneficial for the regeneration of this threatened geophyte at a short-time scale. In this context, a conservation planning with small and controlled fires could maintain the regeneration window for populations of rare Mediterranean geophytes. To cite this article:

Annales de géographie, 2006

La place de l’Homme dans l’environnement méditerranéen apparaît plus que jamais comme déterminant... more La place de l’Homme dans l’environnement méditerranéen apparaît plus que jamais comme déterminante, puisque ses impacts et ses choix de gestion déterminent le maintien de la forte biodiversité du bassin méditerranéen. Constitué de 10 hotspots régionaux et une cinquantaine de zones refuges, la région méditerranéenne est fragilisée par la rapidité et l’ampleur des changements environnementaux en cours ou prévus à court terme. À une échelle plus fine, le hotspot régional des Alpes maritimes, représente le plus important centre d’endémisme de l’arc alpin, mais il subit depuis ces dernières décennies des mutations environnementales drastiques. Les confrontations effectuées entre la localisation des zones refuges et celle des territoires fortement anthropisés montrent que les refuges représentent des territoires parmi les plus menacés par l’anthropisation, car ils sont soumis à des pressions démographiques supérieures à la moyenne. Ce constat, particulièrement net à l’échelle du bassin méditerranéen, est un peu atténué à une échelle inférieure, celle des Alpes maritimes. Ainsi, face à l’ampleur et à la croissance des menaces anthropiques sur la biodiversité méditerranéenne, il est nécessaire de mettre en place rapidement une politique intégrative de conservation qui considère en priorité ces zones refuges.

Molecular Phylogenetics and Evolution, 2014

The intraspecific genetic variability of siliceous and calcareous Gentiana species is shaped by c... more The intraspecific genetic variability of siliceous and calcareous Gentiana species is shaped by contrasting demographic and re-colonization processes, Molecular Phylogenetics and Evolution (2013),

HAL (Le Centre pour la Communication Scientifique Directe), Sep 2, 2007

International audienc

HAL (Le Centre pour la Communication Scientifique Directe), Sep 10, 2007

International audienc

Journal for Nature Conservation, Jun 1, 2021

Erosion of natural habitats due to urban sprawl constitutes a major threat to biodiversity. The d... more Erosion of natural habitats due to urban sprawl constitutes a major threat to biodiversity. The development of the Plant Micro-Reserve (PMR) is an efficient concept for the in situ conservation of rare plants with narrow ecological niche and threatened by human impacts. We provide a framework for initiating site selection of PMRs, including evolutionary and ecological uniqueness. The proposed cross-analysis is based on (i) the estimate of population vulnerability, (ii) the contribution of each population to the evolutionary originality of the species by designating conservation units, and (iii) the gap analysis of the current protection status of the populations. As a case study, we apply this framework to the Nice Snowflake Acis nicaeensis, a narrow Mediterranean endemic plant of the French-Italian Riviera which, being caught in the turmoil of urban sprawl, is threatened by tremendous anthropogenic pressures. On the basis of historical data (past land-use and herbarium data) we show that over the last 150 years, the impact of urbanization has been severe for 70 % of the populations and has caused the disappearance of at least 11 of them, i.e. 20 % of the known populations. Similar levels of urban sprawl are observed between the most vulnerable and already extinct populations. In this context of biodiversity decline, our cross-analysis highlights that two of the five conservation units call for a rapid setting up of PMRs because of their high originality and their great risk of extinction: one unit including the populations of the Principality of Monaco and one unit that includes the populations of Nice and its surroundings. This study demonstrates the importance of integrating population vulnerability and conservation units. In a context of huge urbanization our approach makes a clear case for the design of PMRs.

Annales de géographie, 2006

Man’s role appears to be central in the future of the Mediterranean environment, because his impa... more Man’s role appears to be central in the future of the Mediterranean environment, because his impact and management choices are responsible for the persistence of this high biodiversity in the Mediterranean basin. With 10 regional hotspots and 50 plant biodiversity refuge areas, the Mediterranean region is threatened by the quickness and the severity of the current and forecasted environmental changes. More precisely, the Maritime Alps regional hotspot constitutes the most important endemic center of the whole Alps region, but it has been subjected to drastic environmental transformations for the last decades. The comparisons between the distribution of refuges and human threats exhibit similar spatial patterns, both at the Mediterranean region scale and, to a lesser extent, at the Maritime Alps hotspot. Refuge areas constitute some of the most threatened territories due to a higher than average demographic pressure. This observation which is very clear at the level of the Mediterranean basin is slightly mitigated at the lower scale, the Maritime Alps. Thus, facing the increasing threats on the Mediterranean biodiversity, it's essential to quickly undertake an integrative conservation framework at the Mediterranean scale with a prioritization toward refuge areas.

Journal for Nature Conservation

Biodiversity and Conservation, Nov 4, 2016

Current biodiversity patterns are a temporary state in a continuum of ecological and evolutionary... more Current biodiversity patterns are a temporary state in a continuum of ecological and evolutionary changes. Conservation policies must incorporate this dynamic to ensure the long-term conservation of biodiversity which is particularly challenging in a context of extreme urbanization. An original approach, rarely used for plant conservation, is to define conservation units to set conservation priorities within species by combining ecological and evolutionary divergences. In the Maritime Alps (southern France), the ecological and evolutionary divergences between the populations of Acis nicaeensis has allowed us the determination of conservation units of this endemic plant threatened by severe urbanization and land-use changes. Phylogeographical data (cpDNA haplotype) were considered as a proxy for evolutionary legacy, and ecological data (multivariate analysis of habitat) were used as a proxy for ecological distinctiveness. Our goal was to explore the potential of this approach to assess vulnerability and set conservation priorities for narrow endemic species in the context of conflict between biodiversity and human activities. The results highlight five different conservation units within A. nicaeensis distribution. Genetic and ecological divergences are present at fine-scale. This pattern is highly endangered by urbanisation. This study highlights the vulnerability of conservation units near the coast whose Communicated by Daniel Sanchez Mata.