56 research outputs found

    The preliminary results of modern and past vegetation comparison by using different pollen monitoring methods in calcareous spring fens

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    We investigate whether spring fens can be separated from raised bogs based on pollen data and study how much the pollen reflects the surrounding landscape and how much it reflects the local conditions in the fen or bog. Analysis is based on pollen trap and top sediment sample records obtained from Vedruka bog and Vesiku spring fen in Saaremaa island, Estonia

    Carbon accumulation rate in a raised bog in Latvia, NE Europe, in relation to climate warming

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    The carbon accumulation rate (CAR) over the last 180 years was estimated by measuring carbon concentrations in 1-cm layers in a fine-resolution dated and analysed peat sequence in Teiči Bog, Latvia, NE Europe. We used the Granger causality test to examine the temporal (lagged) relationships between the CAR and the historical climate variables. Our results showed that the average CAR was 192 g C m–2 yr–1 during the last 180 years and 169 g C m–2 yr–1 when excluding the acrotelm where decomposition and the stock of carbon are still not in the balance. The Granger causality test showed significant positive temporal associations between the temperature and the CAR, indicating that the temperature is a likely driver of the CAR in the bog. The overall pattern of the CAR resembles the changes in other peat bogs of Europe and underlines that the bogs in NE Europe most likely accumulate more C with increasing temperatures – that should be considered when addressing the issues of CAR and CO2 emissions at local and regional climate and policy initiatives

    A global database for metacommunity ecology, integrating species, traits, environment and space

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    The use of functional information in the form of species traits plays an important role in explaining biodiversity patterns and responses to environmental changes. Although relationships between species composition, their traits, and the environment have been extensively studied on a case-by-case basis, results are variable, and it remains unclear how generalizable these relationships are across ecosystems, taxa and spatial scales. To address this gap, we collated 80 datasets from trait-based studies into a global database for metaCommunity Ecology: Species, Traits, Environment and Space; “CESTES”. Each dataset includes four matrices: species community abundances or presences/absences across multiple sites, species trait information, environmental variables and spatial coordinates of the sampling sites. The CESTES database is a live database: it will be maintained and expanded in the future as new datasets become available. By its harmonized structure, and the diversity of ecosystem types, taxonomic groups, and spatial scales it covers, the CESTES database provides an important opportunity for synthetic trait-based research in community ecology

    GrassPlot - a database of multi-scale plant diversity in Palaearctic grasslands

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    GrassPlot is a collaborative vegetation-plot database organised by the Eurasian Dry Grassland Group (EDGG) and listed in the Global Index of Vegetation-Plot Databases (GIVD ID EU-00-003). GrassPlot collects plot records (releves) from grasslands and other open habitats of the Palaearctic biogeographic realm. It focuses on precisely delimited plots of eight standard grain sizes (0.0001; 0.001;... 1,000 m(2)) and on nested-plot series with at least four different grain sizes. The usage of GrassPlot is regulated through Bylaws that intend to balance the interests of data contributors and data users. The current version (v. 1.00) contains data for approximately 170,000 plots of different sizes and 2,800 nested-plot series. The key components are richness data and metadata. However, most included datasets also encompass compositional data. About 14,000 plots have near-complete records of terricolous bryophytes and lichens in addition to vascular plants. At present, GrassPlot contains data from 36 countries throughout the Palaearctic, spread across elevational gradients and major grassland types. GrassPlot with its multi-scale and multi-taxon focus complements the larger international vegetationplot databases, such as the European Vegetation Archive (EVA) and the global database " sPlot". Its main aim is to facilitate studies on the scale-and taxon-dependency of biodiversity patterns and drivers along macroecological gradients. GrassPlot is a dynamic database and will expand through new data collection coordinated by the elected Governing Board. We invite researchers with suitable data to join GrassPlot. Researchers with project ideas addressable with GrassPlot data are welcome to submit proposals to the Governing Board

    Plant species diversity in semi-natural grasslands. Effects of scale, landscape structure and habitat history

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    The thesis examines the impact of present and past landscape structure, habitat history and management on different aspects of present-day plant species diversity in fragmented semi-natural grasslands in Sweden and in Estonia. Species diversity was significantly associated with present and/or past grassland connectivity in the majority of the studies in the thesis. However, relationships between diversity and habitat connectivity differed between the studies – depending on the the group of studied species and on the scale of study. Present grassland connectivity was positively associated with fine-scale (0.25–1 m2), rather than large-scale (>0.1 ha), species diversity – suggesting that small-scale diversity may be more sensitive to habitat fragmentation than large-scale diversity. High landscape diversity in the surroundings of the grassland sites had a positive effect on species richness, emphasizing the importance of considering landscape context when examining the influence of landscape-scale processes on plant communities. Within-habitat environmental heterogeneity had a positive influence on both large-scale and fine-scale species diversity. Grassland history (age; previous land-use) had a significant impact on present-day species diversity. Large-scale species richness increased with grassland age (30 to >280 years of grassland continuity). While fine-scale species richness was independent of habitat age, the proportion of grassland specialist species on a fine scale was higher in old grasslands and in grasslands on previously forested land than in previously arable sites. Diversity was positively associated with Late Iron Age human population density – indicating that human land-use legacies that influence present-day plant species diversity may reach back more than 800 years. Grassland management by grazing or mowing is, by definition, essential for the persistence of semi-natural grasslands. Fine-scale species diversity decreased with decreasing grazing intensity in the studied grasslands. The results also suggest that simple descriptors (distance from settlements; human population density) related to human activities may provide good indicators for management processes that influence levels of small-scale plant species diversity. Comparison of the responses of fine-scale species evenness and richness to differences in landscape structure and history showed that evenness was associated mainly with historical factors, while richness was also influenced by contemporary landscape structure. Patterns of species co-occurrence were associated with different factors on different spatial scales. The results of the thesis emphasize the importance of (a) examining different aspects of species diversity on multiple spatial scales (b) including information on historical habitat distribution, when studying the community responses to habitat fragmentation and when making conservation decisions for fragmented habitats

    Phytobenthic communities of Väinameri

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    https://www.ester.ee/record=b3582316*es

    Eesti rannikuvete fütobentiliste koosluste klassifikatsioon ja sõltuvus keskkonnafaktoritest

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    https://www.ester.ee/record=b5501572*es
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