The specific vulnerability of plant biodiversity and vegetation on Mediterranean islands in the face of global change

International audienceThe numerous Mediterranean islands (> 10,000) are very important from a biodiversity point of view, both in term of plant species (numerous endemics, presence of `climate relicts') and of ecosystems' assemblage. These patterns can be explained by complex interactions between a highly heterogeneous historical biogeography and ecological processes related to diverse island conditions. Furthermore, most of the ups and downs of this biodiversity were closely linked with human pressures which have changed many times through the long socio-ecological history of these island landscapes since the Neolithic period. At present, insular plant biodiversity and rural landscapes are threatened by diverse global environmental changes related to urbanization, habitat fragmentation, unsustainable tourism and other practices (e.g. overgrazing, forest fires), and by other more recent drivers such as climate warming and aridification, sea-level rise and biological invasions. Some of these impacts will be exacerbated on islands because of no (or highly limited) adjacent areas of expansion, notably on the smallest ones (i.e. size < ca. 1000 ha). With regards to the biome crisis facing the Mediterranean basin and induced by human activities, islands constitute key ecological systems and `current refugia' to ensure the long-term preservation of coastal plant biodiversity. They also represent fascinating ecological systems to disentangle the role of environmental versus human pressures on spatially simplified communities of the Mediterranean coastal areas. Future detailed studies of these `natural island microcosms' could greatly improve our knowledge of the functional and evolutionary processes induced by rapid environmental changes in this region

Hot-Spots Analysis for Conservation of Plant Biodiversity in the Mediterranean Basin

Volume: 84Start Page: 112End Page: 12

Using phylogeography to define conservation priorities: The case of narrow endemic plants in the Mediterranean Basin hotspot

International audienceThe preservation of rare and vulnerable narrow endemics is a key issue in biological conservation since they represents distinct evolutionary units emerging from various temporal processes. Phylogeography has proved to be a relevant tool for the distinction of evolutionary structures resulting from contrasted biogeographical events. However, the historical and evolutionary perspective provided by phylogeography is still curiously underused in plant conservation genetics. Here we perform a comprehensive review of almost all case studies related to the structure of genetic diversity of Mediterranean narrow endemic plants (MNEs) of the Mediterranean Basin hotspot. The use of genetic diversity structure for phylogeographical inference and for the definition of conservation units was examined for ninety-two studies corresponding to eighty-three taxa. Most of these taxa are perennial herbs with a narrow ecological niche. Geographical coverage is heavily biased since 91.5% of the analyzed MNEs are located in the northwestern part of the Mediterranean region. Half of the studied species have moderate to high genetic diversity, and genetic differentiation is geographically structured in 56% of the case studies indicating that MNEs are not "evolutionary dead-ends" but are sheltering a strong evolutionary legacy calling for conservation planning at populations' level. However, a minority of studies used these genetic structures to define conservation units. The main insight of this review is that phylogeography is generally overlooked in conservation genetics and that the design of conservation units has not been a priority issue, rather a way to enhance the scope of genetic diversity analyses. Nevertheless, the strong phylogeographic structure revealed in several studies of MNEs underlines the relevance of phylogeography and we argue that comparative phylogeography of several co-occurring taxa could greatly improve the proactive conservation planning of threatened endemic plants within biodiversity hotspots

Histoire de l’environnement et des usages anthropiques sur l’île de Cavallo (archipel des Lavezzi, Corse)

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Sea-level rise and consequences on terrestrial biodiversity on Cavallo Island (Corsica): a 7000 years story

International audienc

Sea-level rise and consequences on terrestrial biodiversity on Cavallo Island (Corsica): a 7000 years story

International audienc

How fossils beetle contribute to biodiversity conservation policy: example from the Mediterranean island of Cavallo (southern Corsica, France)

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Histoire de l’environnement et des usages anthropiques sur l’île de Cavallo (archipel des Lavezzi, Corse)

International audienc

Histoire de l’environnement et des usages anthropiques sur l’île de Cavallo (archipel des Lavezzi, Corse)

International audienc