Search results for "Indicator value"
showing 10 items of 21 documents
Reliability and effectiveness of Ellenberg’s indices in checking flora and vegetation changes induced by climatic variations
2001
Two methods are proposed to assess the significance of time-spanned local variations of Ellenberg’s indicator values in floristic and phytosociological data sets respectively. Both methods are based on frequencies and averages of the indicator values within and among data sets. Main goal of proposed methods is to determine the threshold above which the observed variations are to be considered significant. In order to relate the observed floristic variations to recent climatic changes, attention was focused on the Ellenberg’s indices dealing with the main climatic variables: heliophany, temperature and precipitation. Study-cases from Zannone Island (Pontine Archipelago, Mediterranean region)…
Bryophytes of Europe Traits (BET) dataset
2023
The Bryophytes of Europe Traits (BET) dataset includes values for 65 biological and ecological traits and 25 bioclimatic variables for all 1816 bryophytes included in the European Red List (Hodgetts et al. 2019). The traits are compiled from several regional trait datasets and manually complemented using Floras, species-specific literature and expert knowledge. The bioclimatic variables are calculated using the European range of each species. Details regarding the trait compilation and extraction of bioclimatic variables can be found in the corresponding data paper (Van Zuijlen et al. 2023).
A test on Ellenberg indicator values in the Mediterranean evergreen woods (Quercetea ilicis)
2015
The consistency and reliability of Ellenberg’s indicator values (Eiv) as ecological descriptors of the Mediterranean evergreen vegetation ascribed to the phytosociological class Quercetea ilicis have been checked on a set of 859 phytosociological releves × 699 species. Diagnostic species were identified through a Twinspan analysis and their Eiv analyzed and related to the following independent variables: (1) annual mean temperatures, (2) annual rainfall. The results provided interesting insights to disentangle the current syntaxonomical framework at the alliance level demonstrating the usefulness of ecological indicator values to test the efficiency and predictivity of the phytosociological…
Loss of Ostracoda biodiversity in Western Mediterranean wetlands
2008
1. The coastal area of Valencia (Spain) in the Western Mediterranean is rich in freshwater and brackish wetlands. These areas are mostly protected for bird conservation but are also highly affected by human impacts. Six shallow lakes located in Ramsar wetland sites of this area were studied in order to assess past and present ostracod biodiversity and relate it to the status of the lakes, taking into consideration the indicator value of these easily fossilizable crustaceans. 2. In all the wetlands studied, ostracod taphocoenoses showed much higher species richness than the corresponding biocoenoses. This is expected from the time accumulative character of the taphocoenosis, but the trend is…
Geographical and ecological outline of metal(loid) accumulating plants in Italian vascular flora
2018
The decontamination of heavy metal polluted soils is one of the major challenges that our industrialized world has to face. Remediation technologies are being developed and employed in order to reduce the potential hazards of metal and metalloid contamination. Plants capable of uptaking metals and metalloids in their tissues can be an effective tool to remove such pollutants from contaminated soils. The use of this plant-driven process (Phytoremediation) requires the knowledge of the right phytoextractors to use when facing different types of contamination. The aim of this paper is to provide an inventory of phytoextractors that can be used in Phytoremediation procedures in Italy. The check…
DEFINING MACROINVERTEBRATE ASSEMBLAGE TYPES OF HEADWATER STREAMS: IMPLICATIONS FOR BIOASSESSMENT AND CONSERVATION
2003
We used data from 235 boreal headwater streams in Finland to examine whether macroinvertebrate assemblages constitute clearly definable types, and how well biologically defined assemblage types can be predicted using environmental variables. Two- way indicator species analysis produced 10 assemblage types, which differed significantly from each other (multiresponse permutation procedure, MRPP). However, based on MRPP and nonmetric multidimensional scaling, there was wide variation among sites within each assemblage type, and high degrees of overlap among assemblage types. Such continuous variation was also evidenced by the low number of effective indicator taxa (indicator value method) for …
Ecological Indicator Values for Europe (EIVE) 1.0
2023
Aims: To develop a consistent ecological indicator value system for Europe for five of the main plant niche dimensions: soil moisture (M), soil nitrogen (N), soil reaction (R), light (L) and temperature (T). Study area: Europe (and closely adjacent regions). Methods: We identified 31 indicator value systems for vascular plants in Europe that contained assessments on at least one of the five aforementioned niche dimensions. We rescaled the indicator values of each dimension to a continuous scale, in which 0 represents the minimum and 10 the maximum value present in Europe. Taxon names were harmonised to the Euro+Med Plantbase. For each of the five dimensions, we calculated European values fo…
Ellenberg-type indicator values for European vascular plant species
2022
This is a dataset of Ellenberg-type indicator values for European vascular plant species described in this article: Tichý L., Axmanová I., Dengler J., Guarino R., Jansen F., Midolo G., Nobis M.P., Van Meerbeek K., Aćić S., Attorre F., Bergmeier E., Biurrun I., Bonari G., Bruelheide H., Campos J.A., Čarni A., Chiarucci A., Ćuk M., Ćušterevska M., Didukh Y., Dítě D., Dítě Z., Dziuba T., Fanelli G., Fernández-Pascual E., Garbolino E., Gavilán R.G., Gégout J.-C., Graf U., Güler B., Hájek M., Hennekens S.M., Jandt U., Jašková A., Jiménez-Alfaro B., Julve P., Kambach S., Karger D.N., Karrer G., Kavgacı A., Knollová I., Kuzemko A., Küzmič F., Landucci F., Lengyel A., Lenoir J., Marcenò C., Moeslun…
Variations spatiales et temporelles de communautés adventices des cultures annuelles en France
2010
Résumé de thèse; National audience
Mapping a-priori defined plant associations using remotely sensed vegetation characteristics
2014
Abstract Incorporation of a priori defined plant associations into remote sensing products is a major challenge that has only recently been confronted by the remote sensing community. We present an approach to map the spatial distribution of such associations by using plant indicator values (IVs) for salinity, moisture and nutrients as an intermediate between spectral reflectance and association occurrences. For a 12 km 2 study site in the Netherlands, the relations between observed IVs at local vegetation plots and visible and near-infrared (VNIR) and short-wave infrared (SWIR) airborne reflectance data were modelled using Gaussian Process Regression (GPR) (R 2 0.73, 0.64 and 0.76 for sali…