Zygmunt Kącki

Distribution, morphology and habitats of Elatine triandra (Elatinaceae) in Europe, with particular reference to the central part of the continent

Abstract Elatine triandra Schkuhr is the most variable and widespread species within the genus Elatine L.; it has been recorded in all continents, except Antarctica, but it is mainly located in Europe. The study is based on an extensive data set of European literature, herbaria and web data that covers the period 1828–2012. The range of the species in Europe is disjunctive, covering the southern and western parts of the Central European Plain and the southern part of the Fennoscandian Shield. At a smaller scale, the species can also be found along some river valleys. In Central Europe many localities, particularly isolated ones in the northern part of the range, are now only historical. From the data set we determined that E. triandra may be best observed between May and October. We found that species records show a near-significant shift since 1828. Depending on the environmental conditions, individuals of the taxon develop as one of two morphs: terrestrial or aquatic. The aquatic morph is characterized by stems, internodes, lamina and petiole that are twice as long as those of the terrestrial form. Elatine triandra seeds show consistent characteristics, both in terms of morphs and populations. Our studies show that the best diagnostic features, in addition to the construction of flowers, are the size, shape and surface structure of seeds. In Central Europe, E. triandra occurs exclusively in communities classified as Isoëto-Nano-Juncetea.

Environmental factors associated with the distribution of floodwater mosquito eggs in irrigated fields in Wrocław, Poland

ABSTRACT: A survey of distribution patterns of floodwater mosquito eggs related to environmental conditions such as moisture and plant associations was conducted by using soil samples from irrigated fields in Wrocław, Poland. Mosquito egg distribution was determined by repeatedly flooding the soil samples with aerated water at a temperature of 25° C. Under laboratory conditions, hatching in installments of Aedes caspius (Pallas) and Aedes vexans (Meigen) were commonly observed. The results show that ∼∼75% of the larvae of Ae. caspius and Ae. vexans hatched after the first flooding under summer-like conditions, whereas, following the second and third flooding, the numbers of hatched larvae were significantly lower. In our study, within one intermediate flooded field, a total of 66 plant species was identified and classified into six communities. All vegetation types were associated by varied egg densities and showed differences both in richness and Shannon-Wiener diversity index as well as in ecological indices for moisture, soil reaction, and nutrient level. Small changes in elevation along the slope within the study area showed a large difference in the distribution of mosquito eggs. The highest average egg density was observed in zones with high occurrence of Phalaris arundinacea, usually prevalent in intermediate flooded and fertile areas. Knowledge of the indicators for the distribution of floodwater mosquito eggs in temporary breeding sites may be essential for organizing a successful, integrated mosquito control program with special regard to microbial control agents.

History and environment shape species pools and community diversity in European beech forests

A central hypothesis of ecology states that regional diversity influences local diversity through species-pool effects. Species pools are supposedly shaped by large-scale factors and then filtered into ecological communities, but understanding these processes requires the analysis of large datasets across several regions. Here, we use a framework of community assembly at a continental scale to test the relative influence of historical and environmental drivers, in combination with regional or local species pools, on community species richness and community completeness. Using 42,173 vegetation plots sampled across European beech forests, we found that large-scale factors largely accounted for species pool sizes. At the regional scale, main predictors reflected historical contingencies related to post-glacial dispersal routes, whereas at the local scale, the influence of environmental filters was predominant. Proximity to Quaternary refugia and high precipitation were the main factors supporting community species richness, especially among beech forest specialist plants. Models for community completeness indicate the influence of large-scale factors, further suggesting community saturation as a result of dispersal limitation or biotic interactions. Our results empirically demonstrate how historical factors complement environmental gradients to provide a better understanding of biodiversity patterns across multiple regions.A continent-wide analysis of community assembly in European beech forests shows different emphasis on historical or environmental effects on species pools across different scales.

The effect of abandonment on vegetation composition and soil properties in Molinion meadows (SW Poland)

Intermittently wet meadows of the Molinion alliance, as with many other grasslands of high-nature value, have become increasingly exposed to abandonment due to their low economic value. The potential consequences of land abandonment are the decrease in species diversity and environmental alterations. The issue of land-use induced changes in plant species composition and soil physico-chemical parameters have been rarely studied in species-rich intermittently wet grasslands. In this study we attempt to i) to identify determinants of plant species composition patterns and ii) to investigate the effect of cessation of mowing on vegetation composition and soil properties. The study was conducted in an area of 36 ha covered with Molinion meadows, comprising of mown sites and sites that were left unmown for 10 years. In total, 120 and 80 vegetation plots were sampled from mown and unmown sites, respectively. In these plots we measured plant community composition and soil physico-chemical parameters. The results have shown that the two groups of variables (soil properties and management) differ considerably in their ability to explain variation in plant species data. Soil variables explained four-fold more variation in plant species composition than management did. The content of soil organic matter, moisture, total nitrogen and exchangeable forms of potassium, calcium and magnesium were significantly higher in mown than in unmown grassland systems. The results revealed that soil organic matter was the component of the soil most strongly affected by management, followed by moisture, magnesium, calcium and potassium in that order. Each of these soil parameters was negatively correlated with the abundances of woody plants and invasive species. We concluded that low-intensity, late time of mowing is suitable grassland management practice to ensure high plant species diversity and sustainability of the grassland ecological system while cessation of mowing not only lead to reduced plant species richness and diversity, but also to reduced nutrient levels in grassland soils.

An Irish national vegetation classification system for aquatic river macrophytes

Co-ordinating Editor: Norbert Hölzel Abstract Aim: To construct a classification system for Irish aquatic river vegetation that is directly comparable to European aquatic vegetation classification units. Location: A total of 2,415 river vegetation plots with a wide geographic distribution across both the Republic and Northern Ireland. Methods: The plots were recorded from a range of river types from upland streams to wadeable lowland rivers. A total of 1,613 plots were classified using supervised Kmeans clustering through the programme JUICE. The Phi coefficient for presence/ absence data was used to measure fidelity of the vegetation communities. Results: The vegetation communities could be initially subdivided in to four main categories: (1) bryophytedominated aquatic vegetation, (2) bryophytedominated marginal vegetation, (3) vascular plantdominated aquatic vegetation and (4) vascular plantdominated marginal/emergent vegetation. Within these four categories the vegetation was classified into seven classes, 18 alliances and 30 associations. Descriptions are given for each including variants and subassociations if found at association level. Conclusions: There is a rich diversity of bryophyte communities within Irish rivers and they are an integral part of the river network, whereas there was less diversity among vascular plant communities. The distinction between some communities was not as sharp as expected for a variety of reasons discussed in this paper, nevertheless, a working classification system was constructed.

Diversity of lowland hay meadows and pastures in Western and Central Europe

Questions Which are the main vegetation types of lowland hay meadows and pastures in Western and Central Europe? What are the main environmental gradients that drive patterns of species composition? Is it possible to classify these grasslands to phytosociological alliances that reflect management practices? Location Western and Central Europe (excluding the Alps and Carpathians). Methods A database of 21 400 vegetation plots of mesic grasslands across Western and Central Europe was compiled. After geographically stratified resampling, semi-supervised classification based on the K-means algorithm was applied to assign a subset of plots into 32 a priori association-level vegetation types and to search for new types within the subset of non-assigned plots. The vegetation plots assigned into the final vegetation types were submitted to another K-means classification to show the grouping into higher-level vegetation types. Results A total of 36 associations were distinguished in the resampled subset of 8277 vegetation plots and were grouped into four large groups: (1) eutrophic and intensively managed hay meadows and permanent pastures; (2) nutrient-rich grasslands developed from recently abandoned fields or managed under irregular practices of mowing and manuring; (3) non-eutrophic lowland and submontane hay meadows; (4) extensively managed pastures and Atlantic grazed hay meadows. A PCoA of the associations of these four groups showed that extensively managed pastures were floristically more similar to non-eutrophic hay meadows than to permanent intensively managed pastures, which was more obvious in the Atlantic region than in Central Europe. Species composition of the lowland hay meadows was clearly differentiated according to biogeographic sectors. Other floristic differences were related to climate, altitude, soil base status and topography. Conclusions This analysis challenges the traditional concept of mesic grassland alliances separating hay meadows from pastures. New classification should be based mainly on the differences in management intensity rather than in management practice. Consequently, nutrient-poor extensive pastures, which currently are not considered in the European Habitats Directive, should receive the same conservation attention as low-intensive hay meadows, because both types of vegetation can be equally species-rich and do not differ substantially in floristic composition from each other.

Lindernia procumbens in Poland: the relationship between weather conditions and the occurrence of the species

Lindernia procumbens in Poland: the relationship between weather conditions and the occurrence of the species New data regarding the occurrence of Lindernia procumbens (prostrate false pimpernel) are discussed and its current geographical range in Poland is given. A comparison of its past and present distribution in Poland indicates an advancement of the distribution limit northwards, which may be caused by climate changes, mostly, by an increased number of heat waves in the warm half-year. The relationship between the occurrence of the species and specific meteorological conditions, especially, unusually hot and dry summer periods, is analysed using long-term meteorological surveys.

Identification of NATURA 2000 forest habitats on the example of Oleśnica Śląska Forest District

Identyfikacja leśnych siedlisk przyrodniczych NATURA 2000 na przykładzie Nadleśnictwa Oleśnica Śląska Identification of NATURA 2000 forest habitats on the example of Oleśnica Śląska Forest District Between 2006 and 2007 the inventory of Natura 2000 species and habitat types was made in Polish State Forests. This work presents the results obtained in Oleśnica Śląska Forest District. First, the subsections, which could represent habitat types, were chosen on the basis of tree stand composition and forest site condition. It resulted in 4 262,67 ha of Natura 2000 habitats, which represented 16,3% of the total forest area of the District. Nine types were found: 91D0, 9160, 9170, 9110, 9190, 91E0, 91F0, 91T0, 9130. As a result of a fieldwork the area of habitats was seriously reduced. The Natura 2000 habitats were found in 446 forest subsections on the total area of 1 761,4 ha. The 9160, 91T0 and 9130 types were not confirmed. The area of slightly degenerated habitats was the highest and it was 56,2% of the total area of all habitats. On the basis of the analysis of 122 relevés collected in Oleśnica Śląska Forest District 7 plant associations were indentified. Their structure was a model to determine the precise criteria for recognition the habitats.