187 research outputs found

    Species sorting drives variation of boreal lake and river macrophyte communities

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    Metacommunity paradigms are increasingly studied to explain how environmental control and spatial patterns determine variation in community composition. However, the relative importance of these patterns on biological assemblages among different habitats is not well known. We investigated the relative roles of local, catchment and spatial variables based on overland and watercourse distances in explaining the variation of community structure of lake and river macrophytes in two large river basins at two spatial extents (within and across river basins). Partial redundancy analysis was used to explore the share of variability in macrophyte communities attributable to local environmental conditions, catchment land cover and space (generated with Principle Coordinates of Neighbour Matrices). We found that local variables had the highest effect on both lake and river macrophyte communities, followed by catchment variables. Space had no or only marginal influence on the community structure regardless of used distance measure. Total phosphorus, conductivity and turbidity of the local variables contributed most for lake macrophytes, whereas pH and color had largest independent contribution for variation in river macrophytes. Size of catchment area and proportion of lakes and agriculture were the most important catchment variables in both habitats. The strong importance of environmental control suggests that both lake and river macrophyte communities are structured by species sorting. This finding gives support to the validity of assessment systems based on the European Water Framework Directive

    Isoëtes sabatina (Isoëtaceae, Lycopodiopsida): Taxonomic distinctness and preliminary ecological insights

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    Isoëtes sabatina is the rarest aquatic quillwort in Europe. Although recently found (2013) in Lake Bracciano (central Italy), the species is just one step away from extinction with an estimated population not exceeding 400 individuals and a spatial range of a few hundred square metres. Lake Bracciano is a deep, oligo-mesotrophic Mediterranean volcanic lake that has been subjected to human activities. From January to October 2017, the lake experienced a dramatic water level decrease (up to −1.50 m), which significantly affected the littoral zone and the habitat of I. sabatina. To improve the chances of survival of I. sabatina, the first eco-taxonomic investigation on this species was carried out to describe its genetic distinctness, physical and chemical requirements and companion species. The phylogenetic position of I. sabatina was investigated by applying standard DNA barcoding methods. Simultaneously, during summer 2019, the physical and chemical features of water and sediments of the I. sabatina population and five small Alpine lakes colonized by Isoëtes echinospora – a supposed close relative – were characterized. These data were then compared with the available data on the trophic requirements of the target obligate aquatic Isoëtes, together with Isoëtes lacustris and Isoëtes malinverniana. The present survey confirmed the taxonomic and ecological distinctness of I. sabatina – providing the first evidence of genetic differentiation from I. echinospora. Isoëtes sabatina grows in waters with temperature, conductivity and total alkalinity up to 30°C, 561 Î¼S cm−1 and 3.45 meq L−1, respectively. The edaphic requirements of I. sabatina confirm its outstanding conservation value, and this study offers a basic understanding of how to prevent its extinction. Now, all possible actions must be taken immediately to save this species

    A characteristic time sequence of epileptic activity in EEG during dynamic penicillin-induced focal epilepsy—A preliminary study

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    AbstractPenicillin-induced focal epilepsy is a well-known model in experimental epilepsy. However, the dynamic evolution of waveforms, DC-level changes, spectral content and coherence are rarely reported. Stimulated by earlier fMRI findings, we also seek for the early signs preceding spiking activity from frequency domain of EEG signal. In this study, EEG data is taken from previous EEG/fMRI series (six pigs, 20–24kg) of an experimental focal epilepsy model, which includes dynamic induction of epileptic activity with penicillin (6000IU) injection into the somatosensory cortex during deep isoflurane anaesthesia. No ictal discharges were recorded with this dose. Spike waveforms, DC-level, time–frequency content and coherence of EEG were analysed. Development of penicillin induced focal epileptic activity was not preceded with specific spectral changes. The beginning of interictal spiking was related to power increase in the frequencies below 6Hz or 20Hz, and continued to a widespread spectral increase. DC-level and coherence changes were clear in one animal. Morphological evolution of epileptic activity was a collection of the low-amplitude monophasic, bipolar, triple or double spike-wave forms, with an increase in amplitude, up to large monophasic spiking. In conclusion, in the time sequence of induced epileptic activity, immediate shifts in DC-level EEG are plausible, followed by the spike activity-related widespread increase in spectral content. Morphological evolution does not appear to follow a clear continuum; rather, intermingled and variable spike or multispike waveforms generally lead to stabilised activity of high-amplitude monophasic spikes

    Integrating dispersal proxies in ecological and environmental research in the freshwater realm

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    Dispersal is one of the key mechanisms affecting the distribution of individuals, populations, and communities in nature. Despite advances in the study of single species, it has been notoriously difficult to account for dispersal in multispecies metacommunities, where it potentially has strong effects on community structure beyond those of local environmental conditions. Dispersal should thus be directly integrated in both basic and applied research by using proxies. Here, we review the use of proxies in the current metacommunity research, suggest new proxies, and discuss how proxies could be used in community modelling, particularly in freshwater systems. We suggest that while traditional proxies may still be useful, proxies formerly utilized in transport geography may provide useful novel insights into the structuring of biological communities in freshwater systems. We also suggest that understanding the utility of such proxies for dispersal in metacommunities is highly important for many applied fields such as freshwater bioassessment, conservation planning, and recolonization research in the context of restoration ecology. These research fields have often ignored spatial dynamics and focused mostly on local environmental conditions and changes therein. Yet, the conclusions of these applied studies may change considerably if dispersal is taken into account

    Drivers of plant traits that allow survival in wetlands

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    Plants have developed a suite of traits to survive the anaerobic and anoxic soil conditions in wetlands. Previous studies on wetland plant adaptive traits have focused mainly on physiological aspects under experimental conditions, or compared the trait expression of the local species pool. Thus, a comprehensive analysis of potential factors driving wetland plant adaptive traits under natural environmental conditions is still missing.In this study, we analysed three important wetland adaptive traits, i.e. root porosity, root/shoot ratio and underwater photosynthetic rate, to explore driving factors using a newly compiled dataset of wetland plants. Based on 21 studies at 38 sites across different biomes, we found that root porosity was affected by an interaction of temperature and hydrological regime; root:shoot ratio was affected by temperature, precipitation and habitat type; and underwater photosynthetic rate was affected by precipitation and life form. This suggests that a variety of driving mechanisms affect the expression of different adaptive traits.The quantitative relationships we observed between the adaptive traits and their driving factors will be a useful reference for future global methane and denitrification modelling studies. Our results also stress that besides the traditionally emphasized hydrological driving factors, other factors at several spatial scales should also be taken into consideration in the context of future functional wetland ecology.Environmental Biolog

    Too much diversity—Multiple definitions of geodiversity hinder its potential in biodiversity research

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    Geodiversity—the diversity of abiotic features and pro-cesses of the Earth's surface and subsurface—is an increasingly used concept in ecological research. A growing body of scientific literature has provided evidence of positive links between geodiversity and biodiversity. These studies highlight the potential of geodiversity to improve our understanding of biodiversity patterns and to complement current biodiversity conservation practices and strategies. However, definitions of geodiversity in eco-logical research vary widely. This can hinder the progress of geodiversity–biodiversity research and make it difficult to synthesize findings across studies. We therefore call for greater awareness of how geodiversity is currently defined and for more consistent use of the term ‘geodi-versity’ in biodiversity research

    Target highlights in CASP14 : Analysis of models by structure providers

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    Abstract The biological and functional significance of selected CASP14 targets are described by the authors of the structures. The authors highlight the most relevant features of the target proteins and discuss how well these features were reproduced in the respective submitted predictions. The overall ability to predict three-dimensional structures of proteins has improved remarkably in CASP14, and many difficult targets were modelled with impressive accuracy. For the first time in the history of CASP, the experimentalists not only highlighted that computational models can accurately reproduce the most critical structural features observed in their targets, but also envisaged that models could serve as a guidance for further studies of biologically-relevant properties of proteins. This article is protected by copyright. All rights reserved.Peer reviewe

    The relationships between biotic uniqueness and abiotic uniqueness are context dependent across drainage basins worldwide

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    [EN] Context: Global change, including land-use change and habitat degradation, has led to a decline in biodiversity, more so in freshwater than in terrestrial ecosystems. However, the research on freshwaters lags behind terrestrial and marine studies, highlighting the need for innovative approaches to comprehend freshwater biodiversity. Objectives: We investigated patterns in the relationships between biotic uniqueness and abiotic environmental uniqueness in drainage basins worldwide. Methods: We compiled high-quality data on aquatic insects (mayflies, stoneflies, and caddisflies at genus-level) from 42 drainage basins spanning four continents. Within each basin we calculated biotic uniqueness (local contribution to beta diversity, LCBD) of aquatic insect assemblages, and four types of abiotic uniqueness (local contribution to environmental heterogeneity, LCEH), categorized into upstream land cover, chemical soil properties, stream site landscape position, and climate. A mixed-effects meta-regression was performed across basins to examine variations in the strength of the LCBD-LCEH relationship in terms of latitude, human footprint, and major continental regions (the Americas versus Eurasia). Results: On average, relationships between LCBD and LCEH were weak. However, the strength and direction of the relationship varied among the drainage basins. Latitude, human footprint index, or continental location did not explain significant variation in the strength of the LCBD-LCEH relationship. Conclusions: We detected strong context dependence in the LCBD-LCEH relationship across the drainage basins. Varying environmental conditions and gradient lengths across drainage basins, land-use change, historical contingencies, and stochastic factors may explain these findings. This context dependence underscores the need for basin-specific management practices to protect the biodiversity of riverine systemsSIOpen Access funding provided by University of Oulu (including Oulu University Hospital). The work for this article was supported by the Academy of Finland’s grant to JHeino for the project GloBioTrends (Grant No. 331957). JGG was funded by the European Union Next Generation EU/PRTR (Grant No. AG325). Work by LMB has been continuously supported by the National Council for Scientifc & Technological Development (CNPq) and Fundação de Amparo à Pesquisa do Estado de Goiás (FAPEG) (grants 308974/2020–4 and 465610/2014–5). PB and ZC were fnancially supported by the National Research Development and Innovation Ofce (NKFIH FK 135 136), and PB was supported by the János Bolyai Research Scholarship of the Hungarian Academy of Sciences BO-00106–21. LB thanks the National Council for Scientifc and Technological Development (CNPq) for the Scientifc Initiation Fellowship for JVASS and the productivity fellowship in research to LSB (process nº. 305929/2022–4). MC was awarded National Council for Scientifc & Technological Development (CNPq) research productivity grant 304060/2020–8 and received grants (PPM 00104–18, APQ-00261–22) from the Fundação de Amparo à Pesquisa do Estado de Minas Gerais. SD and JRGM acknowledge funding by the Leibniz Competition (Grant No. J45/2018) and the German Federal Ministry of Education and Research (BMBF grant agreement number no. 033W034A). DRM was supported by National Council for Scientifc & Technological Development (CNPq) (Grant No. PQ-309763–2020-7). DMPC received a postdoctoral scholarship from P&D Aneel- Cemig GT-611. PH was partially funded by the eLTER PLUS project (Grant Agreement No. 871128). LJ is grateful to 33 Forest, CIKEL Ltd. and Instituto de Floresta Tropical (IFT), Biodiversity Research Consortium Brazil-Norway (BRC), and Norsk Hydro for the fnancial and logistical support for sampling. Brazilian National Council for Scientifc and Technological Development (CNPq) is acknowledged for fnancing the projects and for granting a research productivity fellowship to LJ (304710/2019–9). APJF was supported by Conselho Nacional de Desenvolvimento Científco e Tecnológico (CNPq, Brazil, process no. 449315/2014–2 and 481015/2011–6). RL also received a research productivity fellowship from CNPq (grant # 312531/2021–4). MSL received a postdoctoral scholarship from ANEEL/CEMIG (Project GT-599). Part of feld sampling and aquatic insects processing were funded by Conselho Nacional de Desenvolvimento Científco e Tecnológico (CNPq; 403758/2021–1); Fundação de Amparo à Pesquisa do Estado do Amazonas (FAPEAM; Programa Biodiversa) and INCT ADAPTA II – (CNPq: 465540/2014–7; FAPEAM: 062.1187/2017). NH (308970/2019–5) received productivity fellowships from CNPq. RTM received a fellowship from Biodiversa/FAPEAM (01.02.016301.03271/2021–93). KLM acknowledges fnancial support from the Swiss Federal Ofce for the Environment to undertake data collection. Funding for the Segura River basin project was provided by the Seneca Foundation and the European Fund of Regional Development (PLP10/FS/97). FOR was supported by CNPq research grant. TS was partially funded by grant 13/50424–1 and 21/00619–7 from the São Paulo Research Foundation (FAPESP), and by grant 309496/2021–7 from the Conselho Nacional de Desenvolvimento Científco e Tecnológico (CNPq). FVN was supported by grant #2021/13299–0, São Paulo Research Foundation (FAPESP). ALA acknowledges Brazilian National Council for Scientifc and Technological Development (CNPq, Brazil) for granting a postdoctoral scholarship to her (process number: 167873/2022–9
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