Jindřiška Bojková

Ecology of Leuctra geniculata (Plecoptera: Leuctridae), an atlantomediterranean species on the north-eastern border of its area

The first records of Leuctra geniculata Stephens, 1836 in the north-eastern border of its area (the Czech Republic) are presented and an overview of references, synonyms and distribution of the species is given. The ecological preferences of the species, supported by chemical and hydromorphological parameters, are defined. Probable dissemination paths into the Czech Republic and the supposed life cycle of the species are discussed. Photographs of morphological characters, SEM photos of eggs, associated macroinvertebrate assemblages (EPT taxa) and maps of distribution are included.

Spring fens as a unique biotope of stonefly larvae (Plecoptera): species richness and species composition gradients

Western Carpathian spring fens (groundwater-fed wetlands characterised by specific vegetation) represent a rare and unique biotope whose aquatic insects have not been studied until now. Therefore, the aims of this study were to describe the taxocoenosis of stoneflies and to determine the main environmental factors controlling species composition. The study was carried out in 2006 at 15 sites in the borderland of the Czech Republic and Slovakia. The species richness was surprisingly high. 12 out of all 33 recorded species developed in fens, the others inhabited small springbrooks in the vicinity of fens. The structure of stonefly taxocoenosis was influenced by season and substrate characteristics of the studied fens. The main gradient in species data represented change of species composition from species dwelling in fens with coarse substrate and without vegetation over species reaching high numbers in fine sediment fens to a species found exclusively in fens overgrown by sedges.

Revision of the stonefly collections (Plecoptera) by E. Křelinová and J. Raušer from the Czech Republic

The collections of E. Křelinová (78 species: 16,637 imagines, 13,661 larvae) and J. Raušer (66 species: 4590 imagines, 395 slides of exuviae) sampled at more than 750 sites in 1947–1965 represent one of the most complex stonefly materials in Central Europe. However, these collections remained untreated for more than 40 years and only limited or fragmentary data have been published. Recently, a substantial part of the samples has been redetermined or revised, relocalised using GIS, relabelled and data transferred to a common database. Misidentifications mostly arising from taxonomic changes after 1960 are discussed. Some species, contrary to existing literature data, thus are not reliably documented in the Czech Republic (Oemopteryx loewii, Nemoura erratica, N. fulviceps, Protonemura nimborella, Leuctra carinthiaca, L. handlirschi, L. teriolensis), some others (Chloroperla susemicheli, Siphonoperla burmeisteri, Brachyptera starmachi, Leuctra cingulata, L. pusilla, L. dalmoni) actually represent the first reliable records from the Czech Republic.

Distribution and biology of mayflies (Ephemeroptera) of the Czech Republic: present status and perspectives

The checklist of mayflies of the Czech Republic now comprises 107 species (30 genera, 16 families), 87 spp. found until 1970 (first research period) and 99 after 1970 (second research period). The distribution of these species in principal river basins (Elbe: 95 spp., Danube: 79 spp. and Oder: 55 spp.), their frequency, abundance and spatial distribution (highest richness in the colline zone: 93 spp.) are summarised. Main species traits (current preference, feeding and locomotion types and life cycle) are presented in tables. Saprobiological characteristics, substantially modified or newly suggested in at least 36 spp., are defined according to the Czech Standard. Four species are classified extinct, 7 critically endangered, 7 endangered, 16 vulnerable and 14 near threatened. Long-term changes caused mainly by morphological degradation of potamal watercourses (extinction and area diminishing, re-occurrence at some sites after decades of very scarce frequency or quantitative changes) are discussed.

Diversity patterns of aquatic specialists and generalists:contrasts among two spring-fen mesohabitats and nearby streams

Abstract Habitat specialists and generalists are known to differ in their width of environmental tolerance and their representation can vary along with the ecological contrast of habitats. In this study we explore factors shaping patterns of species richness and abundance of aquatic macroinvertebrate habitat specialists and generalists at isolated spring fens, separately for spring patch and spring brook mesohabitats at each site. We also examined habitat contrast of these unique island-like communities by the comparison of spring fen specialists and habitat generalists shared between the two spring fen mesohabitats and the nearest stream to each of 13 selects fen sites. Aquatic macroinvertebrates (Clitellata, Ephemeroptera, Plecoptera, Trichoptera, and Diptera) were investigated at 62 isolated spring fens, with 357 taxa identified in more than 172,000 individuals collected. We found that specialists experienced a stronger relation to local environmental conditions (i.e. the amount of dissolved oxygen and water conductivity) at both spring mesohabitats than generalists, primarily responding to fen habitat size. In contrast, responses of species abundances at spring patches and spring brooks differed as the abundances were controlled by the amount of oxygen in spring patches and by habitat size in spring brooks. Based on Trichoptera and Diptera assemblages we found a similar contrast between both spring fen sites and nearby streams. Our results suggest a higher resilience of specialist populations in well oxygenated sites and their competitive advantage over generalists at these sites, which stresses the importance to prevent any significant decrease of oxygenation (e.g., by eutrophication or drainage), especially in spring patches.

Environmental filtering of aquatic insects in spring fens: patterns of species-specific responses related to specialist-generalist categorization

Environmental factors driving compositional changes of headwater aquatic assemblages have been widely studied as these habitats are among the most vulnerable environments and host diverse and species-rich assemblages. However, responses of individual species to multiple environmental gradients remain poorly known, despite such information being essential for understanding the differences in metacommunity structuring. This study aims to explore species-specific responses to the main environmental gradients in Central European spring fens and to assess the responses in relation to the specialist-generalist categorization of species. In total, the responses of 40 species were analysed by GLM, cluster analysis and PCA. Spring-fen specialists responded predominantly to water temperature and the proportion of fine particulate organic matter in the substratum, while generalists responded mainly to flow conditions and oxygenation in the combination with various substratum characteristics. Our results revealed that it is not easy to find general patterns in species responses to environmental gradients. However, we found a clear distinction between specialist and generalist species in how the local environment affects their successful colonization and establishment of viable population. This result emphasizes the need to consider species specialization in future ecological studies of aquatic spring biota.

New species of the genus Oligoneuriella Ulmer, 1924 (Ephemeroptera: Oligoneuriidae) from Turkey

Three new species of the genus Oligoneuriella Ulmer, 1924 from Turkey are described, namely Oligoneuriella magna sp. nov., Oligoneuriella paulopilosa sp. nov. and Oligoneuriella pectinata sp. nov. Differential diagnostic characters are given with regard to the previously known Oligoneuriella species. Data on the affinities, biology, and distribution of the new species are also provided. New morphological characters (setation of mouthparts and gill plates) potentially useful for the taxonomy of the genus are introduced.

Two new species of the genus Prosopistoma (Ephemeroptera:Prosopistomatidae) from Iraq and Algeria

In addition to the three so far known species of Prosopistoma Latreille, 1833 from West Palaearctic region, P. pennigerum (Müller, 1785), P. oronti Alouf, 1977 and P. orhanelicum Dalkıran, 2009, two new species are described based on larvae. Prosopistoma helenae sp. n. has been found in Iraq (Tigris River in Mosul) and Prosopistoma alaini sp. n. in Algeria (Oued Isser, Sidi Abdelli). Critical distinguishing characters of all West-Palaearctic species of Prosopistoma are discussed in detail.

Trends in species diversity of lotic stoneflies (Plecoptera) in the Czech Republic over five decades

An unusual data set of Plecoptera, very sensitive aquatic insects, allow diversity changes to be estimated for 175 streams in the Czech Republic between two periods, 1955–1960 and 2006–2011. Substantial overall declines in Plecoptera biodiversity were found. Three‐quarters of the species studied declined in their frequency of occurrence, 48% of which were estimated have undergone a reduction of >30%. Overall, streams either at lowland or submontane altitude, particularly large rivers, lost the most species. A significant decrease in local species biodiversity was found in streams up to 700 m a.s.l., especially in small rivers. The taxonomic dissimilarity between contemporary and previous assemblages increased from montane to lowland altitudes (from ˜30 to ˜70%) and was the same in streams of different size (˜50%). Partitioning of dissimilarity showed that the overall change in dissimilarity was primarily driven by changes in species richness; however, species replacement was not negligible. The results demonstrated that aquatic insect biodiversity (Plecoptera in particular) is substantially declining in Europe, probably to a similar or greater extent than terrestrial insects, with potential implications for biodiversity of running waters. Plecoptera showed a complex response to habitat change, including loss of pollution‐sensitive species and habitat‐specialists as well as common species, which, in some cases, counterbalanced their losses by concurrent colonisation of new sites.

Spring-fen habitat islands in a warming climate: Partitioning the effects of mesoclimate air and water temperature on aquatic and terrestrial biota

Climate warming and associated environmental changes lead to compositional shifts and local extinctions in various ecosystems. Species closely associated with rare island-like habitats such as groundwater-dependent spring fens can be severely threatened by these changes due to a limited possibility to disperse. It is, however, largely unknown to what extent mesoclimate affects species composition in spring fens, where microclimate is buffered by groundwater supply. We assembled an original landscape-scale dataset on species composition of the most waterlogged parts of isolated temperate spring fens in the Western Carpathian Mountains along with continuously measured water temperature and hydrological, hydrochemical, and climatic conditions. We explored a set of hypotheses about the effects of mesoclimate air and local spring-water temperature on compositional variation of aquatic (macroinvertebrates), semi-terrestrial (plants) and terrestrial (land snails) components of spring-fen biota, categorized as habitat specialists and other species (i.e. matrix-derived). Water temperature did not show a high level of correlation with mesoclimate. For all components, fractions of compositional variation constrained to temperature were statistically significant and higher for habitat specialists than for other species. The importance of air temperature at the expense of water temperature and its fluctuation clearly increased with terrestriality, i.e. from aquatic macroinvertebrates via vegetation (bryophytes and vascular plants) to land snails, with January air temperature being the most important factor for land snails and plant specialists. Some calcareous-fen specialists with a clear distribution centre in temperate Europe showed a strong affinity to climatically cold sites in our study area and may hence be considered as threatened by climate warming. We conclude that prediction models solely based on air temperature may provide biased estimates of future changes in spring fen communities, because their aquatic and semiterrestrial components are largely affected by water temperature that is modified by local hydrological and landscape settings.