Over the last 45 years significant changes in the floristic composition, distribution pattern, and dominance structure of phytobenthos were observed in Haapsalu Bay. Although the species composition of macroalgae did not change much over the course of this study, we observed notable changes in the community structure, i.e. algal shares. Some species, e.g. Tolypella nidifica, disappeared, other species such as Chara connivens and Chara baltica appeared for the first time in the study area. Besides, many prevailing species were relocated within the observed area over the course of the study. Another distinct feature of the recent years is that the vegetation had no dominant species. In general decadal variability exceeded yearly variability. There was no single abiotic variable that exerted major influence on phytobenthic communities. Instead we observed a combined effect of multiple environmental variables on phytobenthos communities. This study indicated that the changes in phytobenthic communities in Haapsalu Bay over the last 45 years were mainly due to large-scale weather patterns that determined regional salinity and ice conditions. Salinity sets the dominance pattern of phytobenthic species of freshwater and marine origin within communities. The intensity of ice scrape in turn created new unvegetated substrate and determined the overall phytobenthic cover in the study area. Within these large-scale patterns exposure, depth, and spatial salinity gradients contributed to the variability of small-scale patterns of macrophyte communities. Regional nutrient loading had weak effects on macrophyte communities, mainly in interactions with local abiotic variables and regional weather patterns.

Above Northern Europe, recent climate change, apart from temperature rise, also manifests as shifts in wind climatology and storminess, which, in turn, influences the marine ecosystem via changes in hydrodynamic regime. Based on meteorological and sea level data from the Estonian weather and tide gauge stations, as well as on hydrodynamic modelling experiments with the shallow sea 2D model and wave hindcast for the period 1966-2009, the study includes an analysis of hydrodynamic changes in the Estonian coastal waters and discussion on their possible influences on the biotic component of the littoral zone. In the practically tideless Baltic Sea, the climate change induced variations include spatially contrasting trends in sea level, wave conditions and turbidity. Changes in thermohaline and oxygen conditions are frequently governed by shifts in wind-driven flow patterns and upwelling zones. Variations in spatial distribution of charophytes can serve as indicators for changes in coastal sea hydrodynamic conditions.

A survey for entomopathogenic nematodes (EPNs) of the Steienernematidae and Heterorhabditidae in soils of different crop types of agricultural lands (household plots, commercial fields) in the forest (Polissya) and forest-steppe (Lisostep) zones of Ukraine was carried out in spring, summer and autumn months from 2016 to 2018. In total, 205 soil samples and 92 live-traps were processed. In addition, 98 samples of soil-living larvae and adults of insect crop pests, including cockchafer beetles, click beetle larvae, darkling beetle larvae, caterpillars of the scoops were collected. It is shown that the EPNs distribution and frequency of occurrence depends on the natural geographical features (regional characteristics) and habitat types. EPNs were found in 46 (15.4 %) out 297 samples. The incidence (% of samples) of the entomopathogenic nematodes, and their diversity varied depending on the location-based sampling, the type of agrocenosis, and the predominant agricultural plant species or typical species-edificators. The proportion of entomopathogenic nematodes (Steinernema spp., Heterorhabditis spp.) recovery from regions of Lisostep zone was 16.9 %, and 13.6 % from regions of Polissya zone. The highest number among all positive samples was recorded from the apple trees, Malus domestica Borkh., 1803 (10 samples). The least number of positive samples (one sample) was obtained from sweet cherry trees, Prúnus cérasus L., 1753, junipers, Juniperus communis L., 1753, alfalfa, Medicago sativa L., 1753, common beans, Phaseolus vulgaris L., 1753, and common pumpkin, Cucurbita pepo L., 1753. The steinernematid nematodes were noticeably dominant over heterorhabditid nematodes: 60.8 % vs 39.2 % respectively. Steinernema spp. is widespread in different regions and plots, whereas Heterorhabditis spp. are common in fruit orchards and coniferous decorative perennial plantings.

Goal. Of this study is to present new locality records (from agricultural ecosystems) for Steinernema and Heterorhabditis (Nematoda: Rhabditida: Steinernematidae, Heterorhabditidae) fauna of Ukraine. Methods. The object of our research were entomopathogenic nematodes collected from different localities of Ukraine between 2016 and 2021. We used stereoscopic microscope MBS-9, light microscope Carl Zeiss Primo Star 100x—1000x and specialized keys for entomopathogenic nematodes identification. Results. We analyzed 312 samples for entomopathogenic nematodes (Steinernematidae, Heterorhabditidae). Entomopathogenic nematodes were isolated from Zhytomyr region, Chernihiv region and Kyiv region. Entomopathogenic nematodes from Zhytomyr region and Chernihiv region is a new record for Ukraine. EPN-positive soil samples with Steinernema spp. were noticeably pre-dominating over the Heterorhabditis spp. (ratio 1.5 to 1). Three species of entomopathogenic nematodes (S. carpocapsae, Steinernema sp. «glaseri»-group and H. bacteriophora), have been described. The information on the specimens location and brief notes on the habitats is provided. In present study, we examined differences in the morphological and morphometric characters between two EPN species from different regions/zones of Ukraine. Conclusions. We found new locality records for two entomopathogenic nematodes species: S. сarpocapsae and H. bacteriophora reported from Zhytomyr region and Chernihiv region of Ukraine for the first time. Further studies aiming to improve the knowledge on entomopathogenic nematodes (Steinernema and Heterorhabditis) fauna should focus on collecting in little-known areas and some specific habitats of Ukraine.