Givetian trilete spores of Geminospora from the Volyn–Podillya (Western Ukraine)

Givetian sediments are widely distributed within the Volyn-Podillia margin of the East-European platform (VPO EEP). These are terrigenous-carbonate cyclically constructed formations with a thickness of 102 to 165 m, the stratification of which is complicated due to the facial variability of rocks. Therefore, when studying this stratum, palynology and the implementation of palynostratigraphic delimitation are of great importance. The initial stage of palynological research of Devonian VPO EEP deposits is clear identification of miospores and their monographic study, the main components of which are morphological and morphometric research, taxonomic determination of genera and species by morphological-comparative method, elucidation of their stratigraphic and geographical distribution. The object of research is dispersed miospores. During their taxonomic study, M. V. Oshurkova’s artificial, or formal, taxonomy was used, which modernized the morphological classification of R. Potonier and G. Kremp, clarified palynological terminology, detailed diagnostics of taxa, and gave unified diagnoses of genus forms. For the first time, a monographic description of five species is given according to this classification. They are Geminospora extensa (Naumova) Gao (from 36 to 51 %); up to 10 %: G. decora (Naumova) Archangelskaja, G. tuberculata (Kedo) Allen, G. micromanifesta (Naumova) Archangelskaja, G. notata (Naumova) Obukhovskaja. belonging to the genus Geminospora (Balme) Owens of infraturma Pseudosacciti, subturma Zonocavatitriletes, suprasubturma Cavatitriletes turma Triletes. These are trilete radial zonate cavate hilate spores with ornamented exine. They are main indicators, key and characteristic species of palyzone E of the Givetian of the Middle Devonian.

Main macroinvertebrate community drivers and niche properties for characteristic species in urban/rural and lotic/lentic systems

The effect of urbanization is often reflected both in lotic and lentic habitats, through changes in diversity and structural and compositional changes in macroinvertebrate communities. In this study, we focused on macroinvertebrate assemblage in lotic and lentic ecosystems of the Krąpiel River catchment area (NW Poland) with the following aims: (1) to determine the main driver in structuring lotic and lentic macroinvertebrate communities and the factors that influence them in urban versus rural landscapes; (2) to test whether the diversity of macroinvertebrate assemblages in urban lotic/lentic ecosystems is lower than that in rural landscapes; (3) to identify characteristic macroinvertebrate species for urban and rural lotic/lentic ecosystems; to (4) determine species tolerance ranges and species optimums, with special emphasis on characteristic “urban” and “rural” species. Distance from study sites to built-up areas and conductivity were the main factors contributing to the separation of urban vs. rural habitats. For lotic sites, temperature, the percentage of built-up area, insolation, and oxygen concentration were the main factors significantly associated with changes in community composition. For lentic sites, insolation, temperature, and BOD5 were recognized as the main factors which are significantly associated with changes in community composition. The results for lentic habitats were as expected: average species richness was higher in rural than in urban habitats. The characteristic species for each of the four habitat groups included Mideopsis orbicularis for Lentic rural habitats; Hygrobates longipalpis for Lotic rural habitats; Piona sp. for Lentic urban habitats; Mideopsis crassipes for Lotic urban habitats. Hygrobates longipalpis and Piona sp. were at the opposite sides with respect to the degree of urbanization. Result of this investigation has shown that the impact of urbanization and consequently the implementation of conservation measures should be viewed separately within the lentic and lotic gradient.

Elementome of Endemic Dolomitic Flora: Pterocephalus spathulatus (Lag.) Coult

Unusual dolomite substrates present a phenomenon known as dolomitophily, which refers to the specificity of the flora that grows on them. Within the dolomitic flora, one of the most widespread plants in Spain is the characteristic species Pterocephalus spathulatus (Lag.) Coult., which forms whitish prostrate thymes. The present study focused on the knowledge about the ionome (or elementome) of a characteristic dolomite species and some of its applications, both in terms of its nutritional behaviour and in determining the factors that favour the rich and rare flora growing on dolomitic soils. Soil, foliar, stem and root samples of the species studied were collected from different locations in the south of Spain. The samples were analysed to determine their mineral composition. The Bioconcentration Factor (BCF) and the Translocation Factor (TF) were calculated, relating the values of the mineral contents in the soil, both total and phytoavailable, to the values from the foliar, root and stem samples. It was found that this species was able to accumulate some elements, including B, Cr, Cu, Ni, Ti, Tl and Zn, which can be phytotoxic in high concentrations, and are considered to be some of the main toxic metals in soils. In addition, it was observed that the plant can accumulate metals in the stem and leaves (TF), thus proving that it is capable of transporting them from the root to the aerial part of the plant. The data obtained may indicate that other species in the plant community may possess this bioindicator or even phytoremediation capacity.

Composition and distribution of microplankton in the Barents Sea in connection with the thermohaline structure of the pelagial

The research is devoted to the microplankton from the southwestern part of the Barents Sea, which is under the influence of the central branch of the North Cape Current. The main patterns of distribution for individual species and general parameters of microplankton abundance in June 2019 were revealed. The key biological parameters such as the taxonomic composition of microplankton, level of total biomass and biomass of individual groups, characteristic species and species complexes were described for the water masses of the investigated area during the study.

Morphological and molecular variability of Peridinium volzii Lemmerm. (Peridiniaceae, Dinophyceae) and its relevance for infraspecific taxonomy

Contemporary delimitation of species and populations in the microbial domain relies on an integrative approach combining molecular and morphological techniques. In case of the dinophyte Peridinium volzii, a considerable number of infraspecific taxonomic entities have been reported, but it is unclear at present whether the corresponding traits are stable within reproductively isolated units or refer to intraspecific variability. We established 26 monoclonal strains from Central Europe with a morphology that is consistent for P. volzii and characterised them by sequences gained from the rRNA operon. Ten of such strains, representative for the entire diversity observed, were investigated in detail morphologically using light and electron microscopy. In the molecular tree, P. volzii was monophyletic, sister group of Peridinium willei, and three ITS ribotypes could be distinguished. Some traits corresponding to previously described varieties and forms were found in individual cells across the strains under investigation, but not as stable characters correlating to certain ribotypes. We also observed new morphological variability (e.g., unusual shape of plate 4″). Cell size and displacement of the cingulum were significantly different between certain ribotypes but in turn, such diagnostic traits are impossible to assign to already described taxa due to their ambiguity. Based on the small first apical plate as diagnostic trait and putative apomorphy, P. volzii is a characteristic species but the present data given, we are reserved to accept more than a single reproductive unit. Thus, more research is necessary, including a focus on species delimitation to putative close relatives such as Peridinium maeandricum.

Control of meadowsweet Filipendula ulmaria through a change of management from grazing to mowing at an English floodplain meadow.

Floodplain meadow grassland is a diverse habitat which has become increasingly rare throughout Europe. Meadowsweet Filipendula ulmaria, is a characteristic species of its plant community, however it can become overly dominant in the sward resulting in detrimental effects on the community as a whole. High abundance can reduce both the diversity of the sward, by shading out low growing species, and the quality of the hay crop. An eight-year management trial (2011-2019) was undertaken at Fancott Woods and Meadows SSSI by the BCN Wildlife Trust and the Floodplain Meadows Partnership, to test whether it was possible to reduce the dominance of meadowsweet through an annual hay cut with aftermath grazing instead of grazing management only, across three blocks of experimental treatments. A secondary aim of the trial was to investigate whether a change in management could also increase the plant-species diversity. Three plots were cut in June and then aftermath grazed, compared to three control plots that were only grazed from July onwards. The study found that cover of meadowsweet decreased from 55% to 6% under the annual cut and aftermath grazing treatment compared to a decrease from 58% to 35% in the control (grazed only) areas. This was accompanied by an increase in plant-species diversity in the cut areas compared to control plots. The study concluded that annual cutting can be used to control coarse and dominant meadowsweet effectively, and that cutting followed by aftermath grazing in a floodplain meadow delivers greater botanical diversity compared to grazing alone.

The structure of fish communities in Bistrita River, upstream the confluence with Siret River (Romania)

The researches were carried out in 2020 on the main course of Bistrița River, upstream the confluence with Siret River. The biological material was sampled in 10 sampling sites placed on the main course of Bistrița River. Seventeen fish species were identified, one of them being a non-native one: Pseudorasbora parva. We found that the chub and the Prussian carp are characteristic species. Species diversity is quite high, being identified even 12 fish species in some of the sampling sites. There is an unequal distribution of individuals by species. The main threats in the research area are the organic inputs and the increase of turbidity. However, there are no great imbalances, and there is a good capacity for self-support of aquatic communities.

Factors influencing physical dormancy and its elimination in two legumes

Introduction: Prosopis laevigata (Humb. & Bonpl. ex Willd.) M. C. Johnst, P. glandulosa Torr., Vachellia schaffneri (S. Watson) Seigler & Eibinger, V. pennatula (S. Watson) Seigler & Eibinger and V. farnesiana (L.) Wight & Arn. are characteristic species of semi-arid areas. Their seeds show physical dormancy and are naturally scarified by chewing, trampling, digestive tract of fauna, fire, or washing away during rains. Objective: To describe the morphology of the seed coat of three species of Vachellia and two of Prosopis, and to assess the chemical, mechanical and thermal scarification of seeds. Materials and methods: Chemical (HCl for 30, 120, 150 and 180 min), thermal (80, 100, 120 and 140 °C for 3 min) and mechanical (sanding) scarification were applied. Resistance to breaking by compression was measured. The experimental design was randomized complete blocks per species. Results and discussion: Seeds showed a layer of lignified and impermeable macrosclereids, but the aleurone layer could not be detected. Sanding allowed germination from 81.2 to 100 %. Chemical and thermal treatments showed no differences, only in the case of P. laevigata, chemical scarification for 180 min caused higher germination (72.5 %) compared to the control. Vachellia schaffneri seeds were more resistant to compression (669 N) and had more intense dormancy (0.83), while P. glandulosa had the lowest dormancy (0.42). Conclusions: Mechanical scarification was the best method to eliminate dormancy in Vachellia and Prosopis seeds.

Unveiling the conservation status of the sessile oak forest for their protection and management in the northeast of the Iberian Peninsula

The sessile oak forests found on the northeast of the Iberian Peninsula are ascribed to the Lathyro-Quercetumpetraeae association and play a key role in understanding the ecology of this habitat, as this region represents its xeric limit. For this reason, we analysed the biodiversity patterns and current conservation status of the sessile oak forests in the region. To do so, we collected Braun-Blanquet inventories of 34 plots randomly distributed throughout the sessile oak forests. The results showed a relationship between the climatic conditions and the biodiversity variables. While the richness of the community increased with decreasing temperatures, the characteristic species found within the community decreased at these same temperatures. This result was due to the presence of most companion species in the cool zones at high elevations.Sessile oaks are found close to other communities, such as silver birches and Scot pine forests.On the other hand, in the warm areas at low elevations, the sessile oak community was more established, with plants typical of this type of forest. These slightly warmer zones with sessile oaks are very important in terms of conservation and more vulnerable to climate change and the thermophilization of the community, as has been studied. As such, protecting and managing these forests is key to conserving this community. Nevertheless, as current protection measures do not safeguard most of these forests, it is essential to define a conservation strategy to preserve them. Using the conservation status, we have established criteria to improve the conservation strategy for sessile oak forest on the NE Iberian Peninsula.

Shedding light on typical species: implications for habitat monitoring

Habitat monitoring in Europe is regulated by Article 17 of the Habitats Directive, which suggests the use of typical species to habitat conservation status. Yet, the Directive uses the term “typical” species but does not provide a definition, either for its use in reporting or for its use in impact assessments. To address the issue, an online workshop was organized by the Italian Society for Vegetation Science (SISV) to shed light on the diversity of perspectives regarding the different concepts of typical species, and to discuss the possible implications for habitat monitoring. To this aim, we inquired 73 people with a very different degree of expertise in the field of vegetation science by means of a tailored survey composed of six questions. We analysed the data using Pearson's Chi-squared test to verify that the answers diverged from a random distribution and checked the effect of the degree of experience of the surveyees on the results. We found that most of the surveyees agreed on the use of the phytosociological method for habitat monitoring and of the diagnostic and characteristic species to evaluate the structural and functional conservation status of habitats. With this contribution, we shed light on the meaning of “typical” species in the context of habitat monitoring.