66 research outputs found

    Check list of the bryophytes of Réunion Island (France)

    Get PDF
    A systematic, literature-based compilation of bryophytes of Réunion Island has been made, with the additional examination of herbarium specimens. The list of 148 genera and 404 species and infraspecific taxa of mosses and 87 genera and 241 species and infraspecific taxa of hepatics and hornworts are here reported, including four mosses reported as new to Réunion

    Characterizing and quantifying water content in 14 species of bryophytes present in azorean native vegetation

    Get PDF
    Bryophytes are an important component of plant diversity, may be found from sea level to mountaintops, and are particularly conspicuous on the Azores islands. These plants rely on environmental water, which acquires intercepting rain and dew (liquid water) and uses fog (water vapor), and transports both externally, by capillary forces, and internally, in different cells (specialized or not). This study characterizes and quantifies the ability of six liverworts and eight mosses to retain water, through different pathways, and to lose water by evaporation. Twelve replicates of each species were collected in Azorean native vegetation during the summer of 2016. The absolute water content (AWC) was obtained through measurements of specimens saturated, without free water, and completely dry. Most of the 14-target species showed an ectohydric behavior pattern retaining more than 60% of water through gametophyte surface. The AWC value ranged from 646% in Polytrichum commune to 5584% in Sphagnum subnitens. The water loss by direct evaporation showed, for most of species, an exponential decay curve along time. Understanding how much native bryophytes, acquire, store, and release water into the system contributes not only to the knowledge of native vegetation resilience but also to potential impacts on the availability and quality of water—a major ecosystem service performed by bryophytes.This research was funded by ERANET BIOME MOVECLIM Montane vegetation as listening posts for climate change of the regional government of the Azores, grant number M2.1.2/F/04/2011/NET, and M.C.M.C. was funded by the FUNDO REGIONAL PARA A CIÊNCIA E TECNOLOGIA (FRCT) of the regional government of the Azores, grant number M3.1.2/F/007/2012. R.G. is currently funded by FCT-UIDB/00329/2020-2024 (Thematic Line 1–integrated ecological assessment of environmental change on biodiversity) and Azores DRCT Pluriannual Funding (M1.1.A/FUNC.UI&D/010/2021-2024).info:eu-repo/semantics/publishedVersio

    Developing long-term monitoring of natural areas for a Unesco world heritage site: study case of la Reunion

    Full text link
    La Réunion island, in the Mascarenes, has been recognized as a World Heritage site for its Piton, Cirques and Remparts since 2010. The site, coinciding with the core zone of La Réunion National Park, represents 100000 ha, equivalent to 40 % of the island. These dramatic landscapes of rugged terrain, impressive escarpments, forested gorges are dominated by three cliff-rimmed cirques and two volcanoes ― a dormant massif forming the highest peak, Piton des Neiges (3069 m), and in the eastern part of the island lies the very active volcano, the Piton de la Fournaise (2632 m). The island harbours a wide variety of natural habitats (tropical montane cloud forests, subalpine shrublands, lowland forests, dry forest…), now all remnant in the Mascarene archipelago, that host high levels of endemism for both flora and fauna. Thereby, La Réunion is the most significant contributor towards conservation of terrestrial biodiversity in the Mascarene islands. The Divines project (FEDER) aims at developing innovative methods for characterizing and monitoring terrestrial biodiversity in the long term for conservation managers to ensure the protection of this world heritage site. In this poster, a description of the goals, actions and preliminary results of the DIVINES project will be described from gene to ecosystem levels

    Bryophytes distribution along an altitudinal gradient of native forest in Pico island (Azores): preliminary results of epiphytic genera

    Get PDF
    MOVECLIM, Mid Course Meeting, 2-6 September 2013, Réunion (Mascarenes).The evergreen forests of the Azores offer a great variety of habitats for bryophytes, owing to the diversity of microhabitats and available substrata, and to the hyper-humid conditions they provide. Bryophytes play a vital role in such ecosystems (Homem & Gabriel, 2009). The understanding of species rarity is important in ecological and conservational research

    Cloud water interception and resilience of tropical montane bryophytes to climate change in cloud forests of La Reunion

    Full text link
    Tropical montane cloud forests (TMCFs) are characterized by frequent cloud immersion, host a high diversity of global biodiversity and provide vital ecosystem services to insular populations. Climate change on islands, is expected to both raise the cloud height base as a result of temperature increase and to increase the frequency of extreme events like drought. Bryophytes contribute a significant biomass in these systems yet the role of cloud water and the resilience of bryophytes to drought in island TMCFs is still poorly known. In La Reunion, we implemented a novel method to follow cloud water interception by bryophytes in the TMCF using in situlysimeters. We showed that two abundant TMCF liverworts possess an excellent ability to intercept and store cloud water, and that stored water fluctuated according to climatic conditions. In order to better understand the ecophysiology of TMCF bryophytes, we examined chlorophyll fluorescence, under laboratory conditions, for 16 bryophyte species in response to dehydration and rehydration. This was accompanied by measurements of water retention capacity and relative water content of each species. Highest Water Retention Capacity and Relative Water Content were recorded for Sphagnumsp ( 2174 %: 91,37 %) and Anthocerossp ( 1540 %; 7815 %). Dry down curves showed that species with high water storage capacity are favored by maintaining longer optimal photosynthetic activity. After one week of desiccation, half of the species could recover 50 % of their optimal photosynthetic activity within 24 h of rehydration. Most species, after 7 weeks of desiccation, could not recover their original photosynthetic activity after rehydration. These experiments highlight the presence of various strategies for managing desiccation by TMCF bryophytes at the microhabitat level. Bryophytes inhabiting the TMCF, exhibit a strong strategy in either tolerance or drought avoidance or a combination of both strategies, indicating a better adaptation to drought than expected. However, impact of repetitive drought on the physiology of the TMCF species remains unknown. The multiplicity of responses recorded for TMCF bryophytes regarding their physiology and life forms indicate that climate change will have distinct impacts on species

    Bryophyte diversity and climate change in the Azores: looking to the future to redesign the present

    Get PDF
    Jornadas "Ciência nos Açores – que futuro? Tema Ciências Naturais e Ambiente", Ponta Delgada, 7-8 de Junho de 2013.As alterações que o clima do planeta tem vindo a sofrer nas últimas décadas têm efeitos variados sobre a biodiversidade, alterando a distribuição das espécies e as interacções entre estas, afectando a jusante os serviços de ecossistemas e, consequentemente, o ser humano. Nos Açores, vários desses serviços são garantidos pelos briófitos. Para além das suas funções ecossistémicas, estes organismos respondem rapidamente a variações ambientais, sendo por isso indicados para detectar os efeitos biológicos das alterações climáticas. Este estudo procura determinar que impactos terão as alterações climáticas previstas pelo Intergovernmental Panel on Climate Change sobre a distribuição e composição específica e funcional da brioflora dos Açores e que novos dados podemos integrar no sistema de gestão de áreas protegidas do arquipélago. Para tal, pretende-se inventariar a diversidade específica e funcional de briófitos ao longo de gradientes altitudinais em várias ilhas dos Açores, relacionar os padrões de distribuição encontrados com uma série de factores ambientais e desenvolver, através de modelação bioclimática, previsões da distribuição futura destas espécies em resposta a diferentes cenários de alterações climáticas. Utilizando a brioflora açoriana, pretende-se assim ilustrar de que forma o estudo dos futuros efeitos das alterações climáticas sobre a biodiversidade pode servir como base para o desenvolvimento de estratégias de gestão e conservação da natureza a curto, médio e longo prazos. Ao fazê-lo, estaremos a contribuir para garantir a sustentabilidade do arquipélago, preservando a sua biodiversidade, os serviços dos ecossistemas e os benefícios e lucros por eles gerados em sectores como o do turismo, fortemente ligado à qualidade ambiental das ilhas.ABSTRACT: The changes the planet's climate has undergone in recent decades have numerous effects on biodiversity, altering the distribution of species and the interactions between them, affecting the ecosystem services they provide and, consequently, human beings. In the Azores, many of these services are guaranteed by bryophytes. Besides, these organisms respond quickly to environmental changes, being thus very suitable for exploring the biological effects of climate change. This project aims to determine what will the impacts of climate change, as predicted by the Intergovernmental Panel on Climate Change, on the distribution, taxonomic and functional composition of native forest bryophytes be and which new data can we integrate in the archipelago’s protected areas management system. In order to do that, we will sample the taxonomic and functional diversity of bryophytes along altitudinal gradients in several islands of the Azores in a stratified way, and relate the emerging distribution patterns with a number of environmental factors. Then, using bioclimatic modeling, we will predict the future distribution of these species in response to different climate change scenarios. By means of the Azorean bryophytes, we aim to illustrate how the study of future climate change effects on biodiversity can serve as a foundation for the development of short to long-term nature management and conservation strategies. In doing so, we will help to ensure the sustainability of the archipelago, preserving its biodiversity, ecosystem services and the benefits and profits generated by them in sectors such as tourism, strongly linked to the environmental quality of the islands.Governo dos Açores; Fundo Regional para a Ciência

    Habitat loss and frugivores defaunation in Réunion island (Indian Ocean)

    Full text link
    Whereas human settlement on Mascarene islands occurred only recently during the 17th century, the native insular biota experienced a drastic extinction of the vertebrate fauna mainly explained by rapid habitat transformation. At archipelago scale, La R´eunion is the last of the Mascarene islands with large areas of untransformed habitats still covering 40% of the island area (2512 km2). Conversely, Mauritius native forests covers less than 1% of the initial area (1872 km2) but still retain several native frugivore species that went extinct in La Reunion during early human settlement (fruit bats, skinks, pigeons). In order to explain these patterns, we compare habitat transformation history between both islands using past and present vegetation maps, subfossil archives and reports of early travellers. We also question the consequences of native frugivores extinction at island scale. Preliminary results of forest dynamics studies confirm the lack of recovery of native plant communities after natural disturbance that can be explained by dispersal limitation of most native trees, new plant invasions and drastic changes in frugivores community composition
    corecore