722 research outputs found

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

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    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

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

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    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

    Influence of oxygen pressure and aging on LaAlO3 films grown by pulsed laser deposition on SrTiO3 substrates

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    The crystal structures of LaAlO3 films grown by pulsed laser deposition on SrTiO3 substrates at oxygen pressure of 10-3 mbar or 10-5 mbar, where kinetics of ablated species hardly depend on oxygen background pressure, are compared. Our results show that the interface between LaAlO3 and SrTiO3 is sharper when the oxygen pressure is lower. Over time, the formation of various crystalline phases is observed while the crystalline thickness of the LaAlO3 layer remains unchanged. X-ray scattering as well as atomic force microscopy measurements indicate three-dimensional growth of such phases, which appear to be fed from an amorphous capping layer present in as-grown samples

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

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    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

    Recollements of Module Categories

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    We establish a correspondence between recollements of abelian categories up to equivalence and certain TTF-triples. For a module category we show, moreover, a correspondence with idempotent ideals, recovering a theorem of Jans. Furthermore, we show that a recollement whose terms are module categories is equivalent to one induced by an idempotent element, thus answering a question by Kuhn.Comment: Comments are welcom

    Long-term monitoring across elevational gradients to assess ecological hypothesis : a description of standardized sampling methods in oceanic islands and first results

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    We are launching a long-term study to characterize the biodiversity at different elevations in several Azorean Islands. Our aim is to use the Azores as a model archipelago to answer the fundamental question of what generates and maintains the global spatial heterogeneity of diversity in islands and to be able to understand the dynamics of change across time. An extensive, standardized sampling protocol was applied in most of the remnant forest fragments of five Azorean Islands. Fieldwork followed BRYOLAT methodology for the collection of bryophytes, ferns and other vascular plant species. A modified version of the BALA protocol was used for arthropods. A total of 70 plots (10 m x 10 m) are already established in five islands (Flores, Pico, São Jorge, Terceira and São Miguel), all respecting an elevation step of 200 m, resulting in 24 stations examined in Pico, 12 in Terceira, 10 in Flores, 12 in São Miguel and 12 in São Jorge. The first results regarding the vascular plants inventory include 138 vascular species including taxa from Lycopodiophyta (N=2), Pteridophyta (N=27), Pinophyta (N=2) and Magnoliophyta (N=107). In this contribution we also present the main research question for the next six years within the 2020 Horizon

    Spectroscopic Diagnostics of Polar Coronal Plumes

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    Polar coronal plumes seen during solar eclipses can now be studied with space-borne telescopes and spectrometers. We briefly discuss such observations from space with a view to understanding their plasma characteristics. Using these observations, especially from SUMER/SOHO, but also from EUVI/STEREO, we deduce densities, temperatures, and abundance anomalies in plumes and inter-plume regions, and discuss their implications for better understanding of these structures in the Sun's atmosphere.Comment: 5 pages, 3 figures; To appear in "Magnetic Coupling between the Interior and the Atmosphere of the Sun", eds. S.S. Hasan and R.J. Rutten, Astrophysics and Space Science Proceedings, Springer-Verlag, Heidelberg, Berlin, 200
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