Madagascar’s extraordinary biodiversity: Evolution, distribution, and use

Madagascar's biota is hyperdiverse and includes exceptional levels of endemicity. We review the current state of knowledge on Madagascar's past and current terrestrial and freshwater biodiversity by compiling and presenting comprehensive data on species diversity, endemism, and rates of species description and human uses, in addition to presenting an updated and simplified map of vegetation types. We report a substantial increase of records and species new to science in recent years; however, the diversity and evolution of many groups remain practically unknown (e.g., fungi and most invertebrates). Digitization efforts are increasing the resolution of species richness patterns and we highlight the crucial role of field- and collections-based research for advancing biodiversity knowledge and identifying gaps in our understanding, particularly as species richness corresponds closely to collection effort. Phylogenetic diversity patterns mirror that of species richness and endemism in most of the analyzed groups. We highlight humid forests as centers of diversity and endemism because of their role as refugia and centers of recent and rapid radiations. However, the distinct endemism of other areas, such as the grassland-woodland mosaic of the Central Highlands and the spiny forest of the southwest, is also biologically important despite lower species richness. The documented uses of Malagasy biodiversity are manifold, with much potential for the uncovering of new useful traits for food, medicine, and climate mitigation. The data presented here showcase Madagascar as a unique living laboratory for our understanding of evolution and the complex interactions between people and nature. The gathering and analysis of biodiversity data must continue and accelerate if we are to fully understand and safeguard this unique subset of Earth's biodiversity

Madagascar’s extraordinary biodiversity: Threats and opportunities

Madagascar's unique biota is heavily affected by human activity and is under intense threat. Here, we review the current state of knowledge on the conservation status of Madagascar's terrestrial and freshwater biodiversity by presenting data and analyses on documented and predicted species-level conservation statuses, the most prevalent and relevant threats, ex situ collections and programs, and the coverage and comprehensiveness of protected areas. The existing terrestrial protected area network in Madagascar covers 10.4% of its land area and includes at least part of the range of the majority of described native species of vertebrates with known distributions (97.1% of freshwater fishes, amphibians, reptiles, birds, and mammals combined) and plants (67.7%). The overall figures are higher for threatened species (97.7% of threatened vertebrates and 79.6% of threatened plants occurring within at least one protected area). International Union for Conservation of Nature (IUCN) Red List assessments and Bayesian neural network analyses for plants identify overexploitation of biological resources and unsustainable agriculture as themost prominent threats to biodiversity. We highlight five opportunities for action at multiple levels to ensure that conservation and ecological restoration objectives, programs, and activities take account of complex underlying and interacting factors and produce tangible benefits for the biodiversity and people of Madagascar

Madagascar Grass Atlas

Madagascar has a unique heritage in terms of biodiversity. Its separation from Africa set the backdrop for the unique evolution of its flora and fauna. Its isolated island nature gave rise to high endemism and explosive speciation. Of its estimated 12,000 vascular plant species, 83% are unique to Madagascar (Madagascar Catalogue, 2019). Its richness in ecosystems and biodiversity have led to its classification as a megabiodiverse country (Mittermeier et al, 2007). Madagascar is home to sixteen contrasting vegetation types defined by Moat and Smith (2007): humid forest, western dry forest, south western dry spiny forest-thicket, bare rock, degraded south western dry spiny forest, western sub-humid forest, mangroves, water, wetland, south western coastal bushland, tapia forest, littoral forest, western humid forest, cultivation, degraded humid forest, plateau grassland-wooded grassland mosaic and wooded grassland-bushland. The dominant vegetation type is the plateau grassland-wooded and grassland-bushland mosaic, covering approximately 65 % of the island (map: vegetation in Madagascar). Research on Madagascar’s grasses is a growing area of interest because of their significance for the national economy as well as conservation. The grass family is the most economically important plant family and has always been closely involved in people’s lives. Grasses provide food: rice (Oryza sativa), maize (Zea mays), sugarcane (Saccharum officinarum) and breadwheat (Triticum aestivum). Grasses also provide food for cattle and building material. Some invasive species threaten crop harvests and conservation of protected areas (FAOSTAT, 2019). Poaceae are one of the largest plant families in Madagascar with an estimated 541 species (Vorontsova et al., 2016). The Royal Botanic Gardens Kew began research on the Poaceae of Madagascar in the 1980s through taxonomic work on the bamboos carried out by Soejatmi Dransfield (see Dransfield 2003). With the growth of KMCC a variety of projects have been carried across Madagascar including checklisting (Nanjarisoa et al. 2017), new records for the country (Vorontsova et al. 2014), and an identification guide (Vorontsova et al. 2018). Five new species have been described: Andropogon itremoensis (Vorontsova et al. 2013), two species of Panicum (Vorontsova 2014), Sartidia isaloensis (Vorontsova et al. 2015) and Digitaria bosseri (Vorontsova 2017). Knowledge has been built on rare endemic grasses: Lecomtella (Besnard et al. 2013), Chasechloa (Silva et al. 2017), and all genera designated as endemic (Vorontsova & Rakotoarisoa 2014). Collaborations have been strengthened between RBG Kew and Malagasy institutions, particularly the University of Antananarivo. In spite of this recent progress in Madagascar grass taxonomy there has been a lack of data on species distributions in Madagascar, a knowledge gap affecting both researchers and policy makers. The majority of specimens are held at the MNHN and available online, but unfortunately internet access is not always available to researchers given its cost and low speed in Madagascar. The Grass Atlas of Madagascar presented here is an output of the GBIF BID project to compile these data and make them accessible to users though the GBIF portal (Rabarivola et al. 2019). It is a reference document on the distribution of Poaceae in Madagascar, which we hope will be useful to decision-makers, researchers and managers of protected areas in Madagascar