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Sökning: WFRF:(Dolnik Christian)

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1.
  • Idoia Biurrun, Idoia, et al. (författare)
  • GrassPlot v. 2.00 – first update on the database of multi-scale plant diversity in Palaearctic grasslands
  • 2019
  • Ingår i: Palaearctic Grasslands. - : Eurasian Dry Grassland Group (EDGG). - 2627-9827. ; :44, s. 26-47
  • Tidskriftsartikel (refereegranskat)abstract
    • 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). Following a previous Long Database Report (Dengler et al. 2018, Phytocoenologia 48, 331–347), we provide here the first update on content and functionality of GrassPlot. The current version (GrassPlot v. 2.00) contains a total of 190,673 plots of different grain sizes across 28,171 independent plots, with 4,654 nested-plot series including at least four grain sizes. The database has improved its content as well as its functionality, including addition and harmonization of header data (land use, information on nestedness, structure and ecology) and preparation of species composition data. Currently, GrassPlot data are intensively used for broad-scale analyses of different aspects of alpha and beta diversity in grassland ecosystems.
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2.
  • Biurrun, Idoia, et al. (författare)
  • Benchmarking plant diversity of Palaearctic grasslands and other open habitats
  • 2021
  • Ingår i: Journal of Vegetation Science. - Oxford : John Wiley & Sons. - 1100-9233 .- 1654-1103. ; 32:4
  • Tidskriftsartikel (refereegranskat)abstract
    • Journal of Vegetation Science published by John Wiley & Sons Ltd on behalf of International Association for Vegetation Science.Aims: Understanding fine-grain diversity patterns across large spatial extents is fundamental for macroecological research and biodiversity conservation. Using the GrassPlot database, we provide benchmarks of fine-grain richness values of Palaearctic open habitats for vascular plants, bryophytes, lichens and complete vegetation (i.e., the sum of the former three groups). Location: Palaearctic biogeographic realm. Methods: We used 126,524 plots of eight standard grain sizes from the GrassPlot database: 0.0001, 0.001, 0.01, 0.1, 1, 10, 100 and 1,000 m2 and calculated the mean richness and standard deviations, as well as maximum, minimum, median, and first and third quartiles for each combination of grain size, taxonomic group, biome, region, vegetation type and phytosociological class. Results: Patterns of plant diversity in vegetation types and biomes differ across grain sizes and taxonomic groups. Overall, secondary (mostly semi-natural) grasslands and natural grasslands are the richest vegetation type. The open-access file ”GrassPlot Diversity Benchmarks” and the web tool “GrassPlot Diversity Explorer” are now available online (https://edgg.org/databases/GrasslandDiversityExplorer) and provide more insights into species richness patterns in the Palaearctic open habitats. Conclusions: The GrassPlot Diversity Benchmarks provide high-quality data on species richness in open habitat types across the Palaearctic. These benchmark data can be used in vegetation ecology, macroecology, biodiversity conservation and data quality checking. While the amount of data in the underlying GrassPlot database and their spatial coverage are smaller than in other extensive vegetation-plot databases, species recordings in GrassPlot are on average more complete, making it a valuable complementary data source in macroecology. © 2021 The Authors.
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3.
  • Dengler, Juergen, et al. (författare)
  • GrassPlot - a database of multi-scale plant diversity in Palaearctic grasslands
  • 2018
  • Ingår i: Phytocoenologia. - : Schweizerbart. - 0340-269X. ; 48:3, s. 331-347
  • Tidskriftsartikel (refereegranskat)abstract
    • 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.
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4.
  • Dengler, Jürgen, et al. (författare)
  • Species constancy depends on plot size - a problem for vegetation classification and how it can be solved
  • 2009
  • Ingår i: Journal of Vegetation Science. - : Wiley. - 1100-9233 .- 1654-1103. ; 20:4, s. 754-766
  • Tidskriftsartikel (refereegranskat)abstract
    • Question   While it is well known that species richness depends on plot size, it  is not generally recognised that the same must be true for constancy. Accordingly, many authors use varying plot sizes when classifying   vegetation based on the comparison of constancies between groups of plots. We ask whether the constancy-area relationship follows a general   rule, how strong the effect of plot sizes is on constancies, and if it  is possible to correct constancies for area. Location For empirical evaluation, we use data from plant communities in the   Czech Republic, Sweden and Russia.   Methods   To assess the potential influence of differences in plot size on   constancies, we develop a mathematical model. Then, we use series of   nested plot species richness data from a wide range of community types   (herbaceous and forest) to determine the parameters of the derived   function and to test how much the shape of the constancy-area   relationship depends on taxa or vegetation types.   Results   Generally, the constancy-area relationship can be described by C   (A)=1-(1-C-0)((A/A0)boolean AND d), with C being constancy, A area, C-0   known constancy on a specific area A(0), and d a damping parameter   accounting for spatial autocorrelation. As predicted by this function,   constancies in plant communities always varied from values near 0% to   near 100% if plot sizes were changed sufficiently. For the studied   vegetation types, a two- to fourfold increase in plot size resulted in   a change of conventional constancy classes, i.e. an increase of   constancy by 20% or more.   Conclusions   Vegetation classification, which largely relies on constancy values,   irrespective of whether traditional or modern fidelity definitions are   used, is strongly prone to distorting scale effects when releves of   different plot sizes are combined in studies. The constancy-area   functions presented allow an approximate transformation of constancies   to other plot sizes but are flawed by idiosyncrasies in taxa and   vegetation types. Thus, we conclude that the best solution for future   surveys is to apply uniform plot sizes within a few a priori delimited   formations and to determine diagnostic species only within these   formations. Finally, we suggest that more detailed analyses of constancy-area relationships can contribute to a better understanding of species-area relationships because the latter are the summation of the first for all species.
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5.
  • Dengler, Jürgen, et al. (författare)
  • Working group on dry grasslands in the Nordic and Baltic region – Outline of the project and first results for the class Festuco-Brometea
  • 2006
  • Ingår i: Annali di Botanica N.S.. - 0365-0812. ; 6, s. 73-100
  • Tidskriftsartikel (refereegranskat)abstract
    • The vegetation databank established by our working group covers the classes Festuco-Brometea, Koelerio-Corynephoretea, and Trifolio-Geranietea sanguinei in the Nordic and Baltic region, i.e. NE Germany, Denmark, Norway, Sweden, Finland, N Poland, Lithuania, Latvia, Estonia, and NW Russia. We aim to use these data to develop a consistent supra-national phytosociological classification of these xerothermic vegetation types in the study area and to analyse their biodiversity patterns. Up to now, we located some 12,500 relevés meeting our criteria, and more than 3,500 of them have already been included in the databank. We give an overview of the properties of these relevés as regards coverage of syntaxa and countries, source types, plot sizes, and cryptogam treatment. We also present first analyses for the basiphilous semi-dry grasslands (Brachypodietalia pinnati) within the Festuco-Brometea. For this group of communities, many different and incompatible classification schemes have been proposed. We give an overview of the alliance and association names that have been in use for them in the study area, accompanied by a nomenclatural assessment. The relevés presently included in the databank have been tentatively assigned to those vegetation classes whose diagnostic taxa were prevailing. Accordingly, more than 2,000 relevés have been placed in the Festuco-Brometea. These show considerable floristic differences compared to stands of the southern temperate Brachypodietalia pinnati alliances Bromion erecti, Cirsio-Brachypodion pinnati, and Agrostion vinealis. The presence degrees of Avenula pratensis and Homalothecium lutescens, for instance, are significantly increased in the study area, and those of Festuca rupicola and Euphorbia cyparissias decreased. An analysis of the species-area relationship yielded a power function with z = 0.09 which is considerably lower than increments determined by nested-plot analyses of this commu-nity type, indicating the probable incompleteness of the species lists for many of the larger plots. Finally, we give an outlook on the future objectives of the working group.
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6.
  • Schiefelbein, Ulf, et al. (författare)
  • Lobaria pulmonaria (L.) Hoffm. in the southwestern Baltic – Kattegat area
  • 2021
  • Ingår i: Folia Cryptogamica Estonica. - 1406-2070. ; 58, s. 183-197
  • Tidskriftsartikel (refereegranskat)abstract
    • The past and present distribution of Lobaria pulmonaria in Denmark, northern Germany, northwestern Poland and nemoral parts of Skåne, Blekinge, southwesternmost Småland and southern Öland (Sweden) has been studied. Of 124 localities visited between 2015 and 2018, L. pulmonaria was confirmed at 64 sites, at each of which its habitat ecology and viability were investigated. It is almost extinct in Schleswig-Holstein, in southern Jutland, on the Danish Islands, in southwestern Skåne, in Mecklenburg-Vorpommern and in the western part of Pomerania. It has disappeared almost completely from areas where mesophytic forests form the potential natural vegetation. The commonest habitats for L. pulmonaria are species-poor acidic beech and species-poor oak forests, and the commonest substrates are trunks of beech, followed by oak. L. pulmonaria specimens on about two thirds of the colonized trees were in a healthy condition. The situation is worst in Schleswig-Holstein and on the Danish Islands, but best in Blekinge and central and northern Jutland. Recent distribution seems to be influenced by both anthropogenic (e.g. air pollution by sulphur dioxide and nitrogen and forestry practices) and natural factors (precipitation, temperature, air humidity), as well as unnatural climatic factors (global warming).
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7.
  • Schiefelbein, Ulf, et al. (författare)
  • The lichen genus Myriospora in the Baltic coastal zone of Germany
  • 2015
  • Ingår i: Graphis Scripta. - Tartu. - 0901-7593. ; 27:1-2, s. 27-31
  • Tidskriftsartikel (refereegranskat)abstract
    • Information on the ecology and distribution of Myriospora species in the Baltic coastal zone of Germany isprovided. The three species (M. myochroa, M. rhagadiza, M. smaragdula) occurring in the study area arewidely distributed, but show differences in frequency and distribution pattern. Myriospora rhagadiza is rathercommon but strictly restricted to the Baltic shoreline in contrast to the other two species.
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