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Mercury and methylmercury in Baltic Sea sediments, and Polish and Lithuanian soils /
No full textWe review the current environmental pollution by mercury in the soils of Poland and Lithuania and in the sediments of the Baltic Sea. Mercury is documented to have many negative impacts on the environment as a toxic trace element. In many different chemical forms, it is being released into the environment by both geogenic and anthropogenic activities, with most being released from anthropogenic sources. Methylmercury is considered one of the most toxic forms found in the environment. Mercury levels in sediment and various point sources increased after World War II in the Baltic Sea, which was used as a dumpsite. Previous studies show noticeable differences in total mercury in the Baltic Sea. In the Warta and Odra rivers in Poland, mercury levels are also higher than the background value, though recent findings suggest that river sediments are not the main source of mercury to marine sediments. Concentrations in soils in Poland and Lithuania were below the level of limit values (1 and 1.5 mg/ kg−1 respectively), but Upper Silesia showed concentrations (up to 4.01 mg·kg−1) above the limit values. Furthermore, between 1992 and 2006, mercury levels in Wrocław dropped dramatically. The dominant trees in the area can affect mercury accumulation. No data were available for comparison with the soils in Estonia and Latvia
The physiological responses of wheat and maize seedlings grown under water deficit are modulated by pre-application of auxin-type plant growth regulators /
No full textThe physiological responses of wheat and maize seedlings to exogenous auxin-type compounds 1-[2-chloroethoxycarbonyl-methyl]-4-naphthalenesulfonic acid calcium salt (TA-12) and 1-[2-dimethylaminoethoxicarbonylmethyl]naphthalene chlormethylate (TA-14) application prior to polyethyleneglycol-6000 (PEG) treatment were studied. PEG treatment inhibited seedlings growth and caused alterations in their antioxidant defence which was crop-specific. PEG increased the non-enzymatic antioxidants along with inhibition of enzymatic antioxidant activity in wheat, while in maize the opposite effects were found. The TA-12 and TA-14 applied alone increased most of the growth parameters measured in both crops, as well as the catalase activity and protein content of wheat. The growth of PEG-treated wheat and maize plants was improved by foliar spray with TA-compounds (TAs). Application of TAs before PEG treatment maintained low-molecular weight thiol-containing compounds and protein contents, and catalase and peroxidase activities close to the control levels. This was better expressed in maize than in wheat seedlings. The results showed that the preliminary application of TA-12 and TA-14 can reduce the adverse effects of moderate water deficit by crop-specific adjustment of the antioxidant defence to counteract stress
Current state of critically endangered Neotinea ustulata (Orchidaceae) in Lithuania and report on a new record of the species /
No full textNeotinea ustulata (Orchidaceae) is a rapidly declining species throughout much of its range and is classified as critically endangered in Lithuania. Most of the historical occurrences of the species were concentrated in north-western Lithuania, while the largest extant population was in the southern part of the country. In July 2022, a new population of Neotinea ustulata was discovered in an urbanised habitat in Šiauliai in northern Lithuania. A total of 84 individuals of this species were recorded in the population. In the southern part of Lithuania (Va-rėna distr.), the studied population comprised 86 individuals in 2002 and had decreased to 64 individuals by 2022. The total currently known population of the species in the country consists of about 150 individuals and remains critically endangered. The individuals of Neotinea ustulata studied in Šiauliai were significantly lower and had shorter inflorescences than the plants studied in Varėna district in 2002 and 2022. Since the population of Neotinea ustulata in Šiauliai is in an urbanised area, its conservation poses a significant challenge, making it difficult to make long-term predictions on the development of the population. Therefore, it is essential to continue searching for populations of Neotinea ustulata in the country, perform detailed studies on the plants’ reproductive potential, and properly organise the management and protection of extant populations and their habitats
Classifying and mapping cultural ecosystem services using artificial intelligence and social media data /
No full textQuantifying and mapping cultural ecosystem services are complex because of their intangibility. Data from social media, such as geo-tagged photographs, has been proposed for mapping cultural use or appreciation of ecosystems. However, manual content analysis and classification of large numbers of photographs is time-consuming. The potential of deep learning for automating the analysis of crowdsourced social media content is still being explored in CES research. Here, we use a new deep learning model for automating the classification of natural and human elements relevant to CES from Flickr images. This approach applies a convolutional neural network architecture to analyze over 29,000 photographs from the Lithuanian coast and uses hierarchical clustering to group these photographs. The accuracy of the classification was assessed by comparison with manual classification. Over 37% of the photographs were taken for the landscape appreciation class, and 28% of the photographs were taken of nature, of animals or plants, which represent the nature appreciation class. The main clusters were identified in urban areas, more precisely in the main coastal cities of Lithuania. The distribution of the nature photographs was concentrated around particular natural attractions, and they were more likely to occur in parks and natural reserves with high levels of vegetation and animal cover. This approach that was developed for clustering the photographs was accurate and saved approximately 100 km of manual work. The method demonstrates how analyzing large numbers of digital photographs expands the analytical toolbox available to researchers and allows the quantification and mapping of CES at large geographical scales. Automated assessment and mapping of cultural ecosystem services could be used to inform urban planning and improve nature reserve management
Factors affecting roadkills of semi-aquatic mammals /
No full textSimple Summary Semiaquatic mammal roadkill, specifically the European beaver, Eurasian otter, American mink and muskrat was analyzed in Lithuania in the period 2002-2021. From almost 40,000 recorded roadkill cases for all species, these species were registered 60, 22, 26 and 3 times, respectively, thus being rare events. Registered beaver roadkill numbers correlated with an increased registration effort and traffic intensity, while otter roadkill correlated with a registration effort only, and mink roadkill correlated with an increased population (estimated through its proxy and the number of hunted individuals per year). The roadkill was not always in close proximity to waterbodies, with 38-54% of roadkill of these species occurring over 200 m from the nearest water source. With the American mink and muskrat being invasive species in the EU and the Eurasian otter protected in many countries, it could be considered valuable to enhance the registrations of their roadkill (using targeted efforts by drivers, hunters or other citizen scientists) in order to obtain the extrapolated amount of roadkill and to use this knowledge in species management. We previously showed that registration efforts and traffic intensity explain 90% of variation in mammal roadkill numbers, 70% of variation in the numbers of recorded species and 40% of diversity variation. Here we analyze semiaquatic mammal roadkill in Lithuania in 2002-2021, relating these to the monitoring effort. From 39,936 analyzed roadkill, the European beaver (Castor fiber) was registered 60 times, American mink (Neovison vison) 26 times, otter (Lutra lutra) 22 times and muskrat (Ondatra zibethica) 3 times. The average roadkill indexes were 0.000065, 0.00076, 0.00061 and 0.00010 ind./km/day, and the extrapolated annual roadkill for the country was 44-357, 36-456, 49-464 and 89-144 individuals, respectively. Beaver roadkill numbers correlated with the registration effort and traffic intensity, otter roadkill with registration effort only and mink with hunting bag (number of hunted individuals per year). Roadkill was not always related to proximity to water, with 38-54% of roadkill occurring over 200 m from the nearest water source. With American mink and muskrat being invasive species in the EU and otter protected in many countries, it is valuable to enhance the registrations of their roadkill (using targeted efforts by drivers, hunters or other citizen scientists) to obtain the extrapolated amount of roadkill and to use this knowledge in species management
Effects of natural antimicrobials on Xanthomonas strains growth /
No full textThe aim of this work was to investigate the most promising natural antimicrobials effective for the growth suppression of Xanthomonas spp. bacteria. The research objects were Xanthomonas spp. strains isolated from tubers and stem of plants growing in Lithuania: Xanthomonas translucens NRCIB X6, X. arboricola NRCIB X7, NRCIB X8, NRCIB X9, and NRCIB X10; the supernatants of lactic acid bacteria Lactococcus lactis strains 140/2, 57, and 768/5, Lactobacillus helveticus strains 14, 148/3, R, and 3, Lb. reuteri 3 and 7, Streptococcus thermophilus 43, Enterococcus faecium 59-30 and 41-2; endophytic bacterial strains Bacillus, Pseudomonas, and Paenibacillus spp.; and essential oils of lavender (Lavandula angustifolia), grapefruit (Citrus paradisi), pine (Pinus sylvestris), thyme (Thymus vulgaris), rosemary (Rosmarinus officinalis), peppermint (Mentha piperita), lemon (Citrus limetta), aqueous extracts of blueberries (Vaccinium myrtillus), and cranberries (Vaccinium vitis-idaea). The antimicrobial activity of tested substances was determined by agar diffusion method. Supernatants of Lb. reuteri strain 7 and Lb. helveticus strains 14, R, 3, and 148/3 were found to have a high antimicrobial activity against Xanthomonas spp. bacteria strains when compared to the positive control—1.0% copper sulfate (diameter of inhibition zones was 28.8 ± 0.7 mm). The diameter of inhibition zones of supernatants ranged from 23.3 ± 0.6 mm to 32.0 ± 0.1 mm. Thyme (2.0%) and lavender (2.0%) essential oils inhibited the growth of Xanthomonas spp. strains. The diameter of the inhibition zones was from 14.7 ± 0.8 mm to 22.8 ± 0.9 mm. The aqueous extracts of blueberries had a weak antimicrobial activity. The diameter of inhibition zones ranged from 11.0 ± 0.2 mm to 13.0 ± 0.2 mm
Pesticidal potential of some wild plant essential oils against grain pests Tribolium castaneum (Herbst, 1797) and Aspergillus flavus (Link, 1809) /
No full textThe red flour beetle, Tribolium castaneum, and the mold Aspergillus flavus are well known threats of stored grain commodities, causing nutritional loss and poisoning of stored products, respectively. T. castaneum has developed resistance against most insecticides, leading to the use of extensive amounts of synthetic insecticides to protect stored grains. Synthetic pesticides not only toxify the environment but also cause serious health issues in humans using pesticide treated grains. This study aimed to identify plant-based natural pesticides to control T. castaneum and A. flavus. Essential oils were extracted from fresh aerial parts of Chenopodium ambrosioides, Conyza sumatrensis, Erigeron canadensis, and Tagetes minuta through steam distillation and investigated for insecticidal and anti-fungal activities against adult T. castaneum and A. flavus, respectively. GC–MS analysis of C. sumatrensis revealed the presence of 37.7% cis-lachnophyllum ester, 13.4% germacrene D, and 21.6% limonene, whereas in E. canadensis the major compounds were limonene, germacrene D, and cis-lachnophyllum ester (43.4%, 12.9% and 5.9%, respectively). In bioassays with treated grain, C. sumatrensis and E. canadensis essential oils exhibited excellent toxicity against adult T. castaneum with LD50 of 3.7 and 5.6 mg per 10 g grains whereas in a fumigation bioassay they showed LD50 of 6.6 and 10.6 mg/L, respectively. The essential oils extracted from C. ambrosioides and E. canadensis exhibited good anti-fungal activity against A. flavus. Our findings suggest that essential oils of C. sumatrensis and E. canadensis can play an important role in protecting stored grains from T. castaneum and A. flavus contamination
Global Nepticulidae, Opostegidae, and Tischeriidae (Lepidoptera): temporal dynamics of species descriptions and their authors /
No full textThis study identifies the number of named and described species of three monotrysian, plant-mining lepidopteran families worldwide: Nepticulidae and Opostegidae (Nepticuloidea), and Tischeriidae (Tischerioidea). At the end of 2021, we estimated that a total of 1000 Nepticulidae species, 197 Opostegidae species, and 170 Tischeriidae species have been described since the taxonomic practice of describing species began in the 18th century. We examine and discuss the history of descriptions and authorship of species worldwide for each of the three families. We found that the total (accumulative) number of species described increased with each time period delineated. About five new species were described per year on average, or about 22 new species were described per year in the 21st century. We recognize researchers with the most number of described species in these three taxa
A substantial range expansion of alien Ponto-Caspian amphipods along the eastern Baltic Sea coast /
No full textWe report a considerable range expansion of four Ponto-Caspian amphipod species in transitional waters along the southeastern Baltic Sea coast. Chaetogammarus warpachowskyi and Dikerogammarus haemobaphes were found for the first time in Latvia, the former being common along the coast, while the latter was encountered only in the port of Riga. This indicates a 400 to 600 km expansion along the coast, assuming an origin from the Curonian or Vistula lagoons. We also officially document an expansion for Chelicorophium curvispinum in Latvia of ca. 300 km until Riga, confirming recent unpublished records. Moreover, we document a second invasion route of Pontogammarus robustoides into Estonia from nearby Latvian waters by uncovering a population at the port of Pärnu. This species was previously known in Estonia only from the Gulf of Finland (>500 km from Pärnu). With the exception of D. haemobaphes, all newly recorded species were represented by various life-stages and ovigerous females, indicating viable populations. Overall, our findings reveal that Ponto-Caspian amphipods are much more widespread in the Baltic area than previously known and highlight the need for more stringent monitoring