The main objective of this study was to investigate whether the most common wild plant species of urban grassland can be used for phytoremediation of soils polluted with heavy metals. The study was ...conducted in the city of Varaždin, in northern Croatia. The content of heavy metals (Cd, Cu, Fe, Mn, Ni, Pb, Zn) was determined in soil samples as well as in unwashed and washed plant samples (Taraxacum officinale, Plantago lanceolata, Trifolium repens). The results show that the most polluted site is the railway station, while most sites are polluted by road traffic. The soils are most enriched with Pb, Cu, Zn and Cd. The bioconcentration factors for all three plant species are <1, indicating the relatively low capacity of phytoextraction. A considerable amount of heavy metals is found in the dust deposited on the plant surface, which is confirmed by a statistically significant difference between washed and unwashed plant samples. In addition, the biomass of each plant species that can be removed (in t/ha year), the mass of specific heavy metal that can be removed (in kg/ha), and the years required for phytoremediation are reported. In conclusion, phytoremediation with only common plant species of urban grassland is not possible within a reasonable period of time.
Pollination patterns i.e. the proportions of entomophilous, anemophilous, autogamous and hydrophilous plant species and those useful for the European honey bee (Apis mellifera L.) in the flora and ...vegetation of northern Croatia have been determined. The survey included 507 plant taxa, belonging to 95 plant families. The results show that most plant species depend on insect pollination (73.6%), followed by self-pollination (30%), wind (25%) and water pollination (0.6%). For some plant species there are one, two or more modes of pollination; the largest group consists of pure insect pollination (43%), followed by both insect and self-pollination (27%), pure wind pollination (22%), insect and wind pollination (2.6%), and so on. Overall, 54% of plant species useful to European honey bees were found, of which 51% provide pollen and 47% nectar. These results suggest that A. mellifera could be a potential pollinator for about half of the flora. Analysis shows significant differences in pollination patterns among habitat types and that most entomophilous plant taxa are found in grassland, forest and ruderal sites, indicating that these habitats are most important for pollinators. Other characteristics of plant species, such as flowering time, plant family, life form and origin, were also analysed to determine a possible relationship with pollination.
The aim of this study was to determine the extent and patterns of antimony and tin contamination in soils along railway lines, as there are very few data in the literature on this subject. The study ...was conducted in north-western Croatia. Total and bioavailable concentrations of Sn and Sb were detected using high resolution inductively coupled plasma mass spectrometry (HR-ICP-MS). The following results were obtained: total concentrations of Sb ranged from 0.98 to 52.0 mg/kg and of Sn from 3.04 mg/kg to 97.6 mg/kg. The soil samples showed pronounced Sb and Sn enrichment, up to 87 and 33 times the median value for European soils, respectively. In contrast to the total concentrations, the bioavailable concentrations showed relatively low values. For Sn, the percentage of total content ranged from 0.001 to 0.021%, while for Sb it ranged from 0.001 to 0.136%. Statistical data analysis suggests that the distribution of Sb and Sn in soils near railway lines is influenced by the functional use of the site, distance from the tracks, topography, age of the railway line, and also by soil properties such as soil texture, humus content, and soil pH. This study demonstrates that rail transport is a source of soil pollution with Sn and Sb. The origin of Sb and Sn enrichment is abrasion by brakes, rails, wheels, freight losses, exhaust gasses, etc. Both elements in soils along railway lines pose an environmental risk to humans, agricultural production, and wildlife, and therefore further detailed studies are required.
Aims
To create a comprehensive, consistent and unequivocal phytosociological classification of European marsh vegetation of the class Phragmito‐Magnocaricetea.
Location
Europe.
Methods
We applied the ...Cocktail method to a European data set of 249,800 vegetation plots. We identified the main purposes and attributes on which to base the classification, defined assignment rules for vegetation plots, and prepared formal definitions for all the associations, alliances and orders of the class Phragmito‐Magnocaricetea using formal logic. Each formula consists of the combination of “functional species groups”, cover values of individual species, and in the case of high‐rank syntaxa also of “discriminating species groups” created using the Group Improvement (GRIMP) method.
Results
The European Phragmito‐Magnocaricetea vegetation was classified into 92 associations grouped in 11 alliances and six orders. New syntaxa (previously invalidly published according to the International Code of Phytosociological Nomenclature) were introduced: Bolboschoeno maritimi‐Schoenoplection tabernaemontani, Glycerio maximae‐Sietum latifolii, Glycerio notatae‐Veronicetum beccabungae, Schoenoplectetum corymbosi and Thelypterido palustris‐Caricetum elongatae. Based on a critical revision, some other syntaxa were rejected or excluded from the class Phragmito‐Magnocaricetea.
Conclusions
This work provides the first consistent classification of the class Phragmito‐Magnocaricetea at the European scale, which is an important tool for nature conservation. Our classification largely respects previously existing concepts of syntaxa, but it also proposes modifications to the recently published EuroVegChecklist. This work also provides a protocol that can be used for extending the current classification to new syntaxa and geographical regions.
This paper presents a comprehensive and formalized classification of European marsh vegetation. The work is based on more than 200,000 vegetation plots and provides a consistent protocol and a hierarchic expert system for the classification of 92 phytosociological associations, 11 alliances and six orders of Phragmito‐Magnocaricetea class.
Disturbance indicator values for European plants Midolo, Gabriele; Herben, Tomáš; Axmanová, Irena ...
Global ecology and biogeography,
January 2023, 2023-01-00, 20230101, 2023, Letnik:
32, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Motivation
Indicator values are numerical values used to characterize the ecological niches of species and to estimate their occurrence along gradients. Indicator values on climatic and edaphic ...niches of plant species have received considerable attention in ecological research, whereas data on the optimal positioning of species along disturbance gradients are less developed. Here, we present a new data set of disturbance indicator values identifying optima along gradients of natural and anthropogenic disturbance for 6382 vascular plant species based on the analysis of 736,366 European vegetation plots and using expert‐based characterization of disturbance regimes in 236 habitat types. The indicator values presented here are crucial for integrating disturbance niche optima into large‐scale vegetation analyses and macroecological studies.
Main types of variables contained
We set up five main continuous indicator values for European vascular plants: disturbance severity, disturbance frequency, mowing frequency, grazing pressure and soil disturbance. The first two indicators are provided separately for the whole community and for the herb layer. We calculated the values as the average of expert‐based estimates of disturbance values in all habitat types where a species occurs, weighted by the number of plots in which the species occurs within a given habitat type.
Spatial location and grain
Europe. Vegetation plots ranging in size from 1 to 1000 m2.
Time period and grain
Vegetation plots mostly sampled between 1956 and 2013 (= 5th and 95th quantiles of the sampling year, respectively).
Major taxa and level of measurement
Species‐level indicator values for vascular plants.
Software format
csv file.
Ecological theory predicts close relationships between macroclimate and functional traits. Yet, global climatic gradients correlate only weakly with the trait composition of local plant communities, ...suggesting that important factors have been ignored. Here, we investigate the consistency of climate-trait relationships for plant communities in European habitats. Assuming that local factors are better accounted for in more narrowly defined habitats, we assigned > 300,000 vegetation plots to hierarchically classified habitats and modelled the effects of climate on the community-weighted means of four key functional traits using generalized additive models. We found that the predictive power of climate increased from broadly to narrowly defined habitats for specific leaf area and root length, but not for plant height and seed mass. Although macroclimate generally predicted the distribution of all traits, its effects varied, with habitat-specificity increasing toward more narrowly defined habitats. We conclude that macroclimate is an important determinant of terrestrial plant communities, but future predictions of climatic effects must consider how habitats are defined.
•Estimating missing Ellenberg Indicator Values (EIV) could help plant ecology studies.•We tested and compared several methods for estimating missing EIV from existing data.•Multiple Linear Regression ...and k-Nearest Neighbour performed better than the others.•Statistical methods are more effective than imputation based on expert knowledge.•This approach would greatly facilitate monitoring species with unknown EIV.
Ellenberg indicator values (EIV) are widely used in vegetation ecology, but the values for many species in Southeastern Europe are not available due to incomplete knowledge of their ecology: it is therefore of paramount importance to estimate missing values in existing databases. The entire EIV set for a single species can be missing or a single EIV can be missing for species for which other indicator values are available. Our aim here is to provide a simple method to impute missing values for species who have missing data in a single or multiple EIV. For this purpose, we adopt a multiple imputation procedure and compare a number of imputation methods on the basis of two datasets: i) “indices”, the set of 9 Ellenberg indicators taken from literature, available for 10,824 species and ii) “vegetation”, a set describing the physical and climatic characteristics (Light, Temperature, Continentality, Soil moisture, Nitrogen, Soil pH, Hemeroby index, Humidity, Organic_matter) of 29,935 relevés from Southeastern Europe where at least one tree species is present. The imputation methods we considered are: k-Nearest Neighbour, multiple linear regression (with or without collinearity correction), Reprediction Algorithm, Weighted Averaging (WA) and Weighted Averaging Partial Least Squares (WAPLS) regression. The different methods of imputation were compared by looking at the output produced and its deviation from the “true” observed values for a set of species with known EIVs. We have considered a set of species with known EIVs and proceeded to multiple imputation using the methods above; as a measure of performance we adopted the mean squared error (MSE) estimate, and expert judgement of ecological consistency. Models based on Regression and k-Nearest Neighbour seem to outperform the others. On the contrary, Reprediction algorithm in its different forms: produced less satisfactory results.
Imputation of missing values is generally based on expert knowledge or on some variant of weighted averaging (also known as Hill’s method). Here we show that other methods may be more effective and should be appropriately considered by vegetation scientists, since those may allow the application of EIVs in other biogeographic regions.
The impact of a coal-fired Plomin Power Plant (PPP) in Croatia on PCB soil burden was examined by comparing the occurrence, levels, and profile of PCBs in soil from the PPP with the values determined ...in urban-industrialized soil (Varaždin, Croatia). Soil burden by organochlorine pesticides (OCPs) were also investigated at both locations. Topsoil samples were collected at five distances (100–800 m) along a downwind pollution gradient from the PPP and across the city. The total content of PCBs in 100-m soil was nearly 20-fold the levels found in 800-m soil, which pointed to the PPP as a local source of soil contamination. The PPP soils were dominated by indicator PCB congeners, particularly hexa-homologs. A different profile and mass fraction range of PCBs in soils from PPP and Varaždin area indicated the different sources of contamination. Levels of total PCBs in PPP soils (0.25–19.07 μg kg
−1
) were higher than PCB levels determined in soils from Varaždin (0.29–5.52 μg kg
−1
), partially as a result of higher OC content in PPP soils. PPP soil burden by PCBs corresponded to a lower end of PCB level ranges reported for cities with high population and heavy industry. OCPs were detected at significantly higher levels in Varaždin soils than in PPP soils, with the highest contribution of the DDT-like compounds (DDX) detected in soils affected by river deposits. The
p
,
p′
-DDE/
p
,
p′
-DDT ratio in Varaždin soils indicated a fresh atmospheric input of
p
,
p′
-DDT. The PPP soil analysis detected a presence of only
p
,
p′
-DDE and HCB at levels corresponding to their global environmental presence.
Climate change and nitrogen (N) deposition are among the most important drivers of biodiversity change at a global scale. Although commonly considered separately in applied research, conservation, ...and policy development, both empirical evidence and modelling studies indicate that these two stressors may act synergistically and trigger a more pronounced biodiversity loss than each of them alone. Interactive effects thus need to be considered in biodiversity conservation. In this study, we propose a new method for jointly assessing risk from both stressors to habitats by combining climate envelope modelling and the evaluation of exceedance of empirical critical loads for eutrophication through N deposition. Based on this approach we can calculate a combined risk metric, which is the scaled exceedance of the N critical load and climatic thresholds in the three-dimensional space of N deposition, temperature, and water limitation. We use a habitat map to project this risk metric for 34 EUNIS habitat types across Austria. Resulting risk maps indicated that about 16 % of the area of these natural and semi-natural habitat types is currently at risk from either N exceedance, drought or warming. Using combinations of future climatic (RCP2.5 and RCP8.5) and N deposition (business as usual, current legislation and maximum feasible reduction) scenarios, we predict that the area at risk might increase to up to 19% until 2050, with risk from N-deposition decreasing and risk from climate change increasing. Combined impacts of both stressors affect only up to 2% of the entire evaluated area, but are much more frequent in particular habitat types such as oligotrophic bogs and subalpine to alpine grasslands. We conclude that this method provides a useful screening procedure to identify and compare areas and habitats under combined risk from both stressors and to thus support prioritization and decision making in biodiversity conservation.
Aims
The Raunkiær's system classifies vascular plants into life forms based on the position of renewal buds during periods unfavourable for plant growth. Despite the importance of Raunkiær's system ...for ecological research, a study exploring the diversity and distribution of life forms on a continental scale is missing. We aim to (i) map the diversity and distribution of life forms in European vegetation and (ii) test for effects of bioclimatic variables while controlling for habitat‐specific responses.
Location
Europe.
Methods
We used data on life forms of 8883 species recorded in 546,501 vegetation plots of different habitats (forest, grassland, scrub and wetland). For each plot, we calculated: (i) the proportion of species of each life form and (ii) the richness and evenness of life forms. We mapped these plot‐level metrics averaged across 50 km × 50 km grid cells and modelled their response to bioclimatic variables.
Results
Hemicryptophytes were the most widespread life form, especially in the temperate zone of Central Europe. Conversely, therophyte and chamaephyte species were more common in the Mediterranean as well as in the dry temperate regions. Moreover, chamaephytes were also more common in the boreal and arctic zones. Higher proportions of phanerophytes were found in the Mediterranean. Overall, a higher richness of life forms was found at lower latitudes while evenness showed more spatially heterogeneous patterns. Habitat type was the main discriminator for most of the responses analysed, but several moisture‐related predictors still showed a marked effect on the diversity of therophytes and chamaephytes.
Conclusions
Our maps can be used as a tool for future biogeographic and macro‐ecological research at a continental scale. Habitat type and bioclimatic conditions are key for regulating the diversity and distribution of plant life forms, with concomitant consequences for the response of functional diversity in European vegetation to global environmental changes.
We analysed the diversity and distribution of plant life forms across Europe. Hemicryptophytes dominate in central Europe, while therophytes and chamaephytes thrive in the Mediterranean and dry temperate regions, and chamaephytes also in northern Europe. Habitat type strongly influences these patterns and moisture‐related predictors impact therophyte and chamaephyte diversity.
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