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Regionally varying habitat relationships in lichens: the concept and evidence with an emphasis on North-temperate ecosystems /
No full textHabitat ecology of lichens (lichen-forming fungi) involves diverse adaptations to stressful environments where lichens use specific habitat conditions. Field observations confirm that such habitat ‘preferences’ can vary significantly across species’ distribution ranges, sometimes revealing abrupt changes over short distances. We critically review and generalize such empirical evidence as broad ecological patterns, link these with the likely physiological mechanisms and evolutionary processes involved, and outline the implications for lichen conservation. Non-replicated correlative studies remain only suggestive because the data are frequently compromised by sampling bias and pervasive random errors; further noise is related to unrecognized cryptic species. Replicated evidence exists for three macroecological patterns: (a) regional limiting factors excluding a species from a part of its microhabitat range in suboptimal areas; (b) microhabitat shifts to buffer regionally adverse macroclimates; (c) substrate suitability changed by the chemical environment, notably air pollution. All these appear to be primarily buffering physiological challenges of the adverse conditions at the macrohabitat scale or, in favorable environments, coping with competition or predation. The roles of plasticity, adaptation, dispersal, and population-level stochasticity remain to be studied. Although lichens can inhabit various novel microhabitats, there is no evidence for a related adaptive change. A precautionary approach to lichen conservation is to maintain long-term structural heterogeneity in lichen habitats, and consider lichen ecotypes as potential evolutionarily significant units and a bet-hedging strategy for addressing the climate change-related challenges to biodiversity
Host cells inhabited by Leucocytozoon parasites: are they phylogenetically predictable? /
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Comparative analysis of changes in bird gut microbiome after experimental infection with Plasmodium relictum and Plasmodium homocircumflexum parasites /
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Peculiarities of small mammal ecology in commercial orchards, berry plantations and commensal habitats.
No full textThe main objective of this study was to assess the diversity and relative abundance of small mammals in commercial orchards and berry plantations in Lithuania, as well as the population structure and ecology of small mammal species. During the research, 13 small mammal species were trapped in commercial fruit and berry farms. Therelativeabundanceofthe dominant species common vole (Microtusarvalis), yellow-neckedmouse (Apodemusflavicollis),stripedfieldmouse (A. agrarius) and bank vole(Clethrionomysglareolus) and their proportion in the investigated community varied according to year, season and habitat, with no outbreaks recorded during the study period. According to species proportions in the commercial fruit farms, M. arvalis should be the focal species for the evaluation of plant protection products.Trophic resources in commercial fruit farms are partitioned between trophic groups and between species within groups, so that more species can exploit the limited trophic space simultaneously. Clethrionomys glareolus in the apple orchards is omnivorous, its trophic niche being separated from granivores and herbivores according to δ13C, while being the closest to insectivores according to δ15N. The degree of omnivory of these voles in the orchards differed from that in surrounding meadows and forests. In our analysis of 21 elements, we found that the main sources of variability in elemental concentrations were animal species and age, crop and agricultural intensity, while location, animal gender and crop age were not important.The higher concentrations of Cu, Mn, Bi, Co, Cr, Fe, Ni, Sr and Pb in the muscle and bone of the dominant species of rodents from the crop are as in comparison to those from the control habitats supported the hypothesis that fertiliser and pesticide use in commercial gardens should account for the variation of concentrations of the elements in the muscles and bones of small mammals. Sarcocystis spp. Were detected inApodemus agrarius, A. flavicollis, Clethrionomys glareolus, Microtusarvalis and M. oeconomus in six out of 14 orchards and berry plantations. The overall prevalence of Sarcocystis spp. was 1.38%, that in voles – 2.23%, in mice – 0.79%
Does the Ice Age legacy end in Central Europe? The shrinking distributions of glacial relict crustaceans in Lithuania /
No full textGlacial relict crustaceans are characterized by their affinity for cold and well-oxygenated waters and their limited dispersal ability. They occur in large, deep lakes of Northern and Central Europe and North America, with their distributions shaped by glaciation events. In many countries and especially along the southern distribution edge, glacial relict populations are declining as a result of eutrophication, global warming, and possible adverse interactions with invasive Ponto-Caspian crustaceans. This study assessed the status of three glacial relict malacostracan species (the amphipods Monoporeia affinis and Pallaseopsis quadrispinosa and the mysid Mysis relicta) in Lithuania and modelled their abundance across environmental variables, including the presence of Ponto-Caspian malacostracans. The results showed that M. affinis is probably extinct in the country, whereas M. relicta was found in only nine out of 16 locations from which it was previously recorded. The distribution of P. quadrispinosa also seems to be shrinking. The annual water renewal rate (P. quadrispinosa and M. relicta) and lake depth (P. quadrispinosa) were significantly and positively associated with the relative abundance of relict mysids and amphipods, but no association was found with lake size or with the presence of invasive Ponto-Caspian crustaceans. Both species were less abundant in samples collected in the 21st century compared with the 20th century. Given the biogeographical and ecological importance of glacial relict crustaceans, their widespread declines are of concern and point to the deterioration of habitat quality, essential for other species with similar requirements. Urgent action is needed to improve water conditions and safeguard these communities. In cases where water quality improves, the reintroduction of extirpated relict populations should be considered. One example is Lake Drūkšiai, where these crustaceans became extinct during the operation of the Ignalina nuclear power plant but where conditions improved following the closure of the power plant in 2009
Molecular identification of Sarcocystis species in sika deer (Cervus nippon) of free-ranging populations in Germany and Austria /
No full textIn this study, for the first time, Sarcocystis species were identified molecularly in sika deer (Cervus nippon) that form free-ranging populations in several countries of Europe. Diaphragm muscle samples from 151 deer from 10 populations in Germany and Austria were examined for sarcocysts. By one-gram methylene-blue staining, sarcocysts were recorded in samples of 114 animals (75.5%) which originated from all populations. Sarcocysts were more often (p < 0.0001) recorded in yearling and adult deer than in calves. Infection intensity was generally low with ~ 70% of the sarcocyst positive deer harbouring ≤ 10 sarcocysts per 1-gram diaphragm muscle. Based on cox1 sequence comparison, 10 species of Sarcocystis, all previously reported parasitizing cervids, were identified: S. elongata, S. entzerothi, S. hjorti, S. iberica, S. japonica, S. linearis, S. morae, S. pilosa, S. silva and S. truncata. The prevailing S. hjorti was detected in sika deer of all 10 populations. The identification in sika deer of S. hjorti, S. iberica, S. elongata, S. linearis, S. morae and S. silva constitutes new host records. With the additional species records of this study, the highest number of Sarcocystis species, at least 16, was identified in this host