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Ranunculus sect. Batrachium is one of the most complicated taxonomic groups of aquatic plants. Difficulties of aquatic Ranunculus species delimitation according to morphological features are closely related to recognition of their communities, especially in running waters. The diversity of species in the phytocoenosis characterized by the predominance of Ranunculus species and the main physical-chemical factors of water were studied at 15 sites of 10 different-sized rivers of Lithuania. The rivers have met the criteria of the threatened habitats type 3260 (the EU classification). The communities dominated by R. fluitans and R. pseudofluitans were recorded in different river systems and were not found growing together. The environmental conditions also well separated the two communities. The association Ranunculetum fluitantis was distributed in the rivers on silicate substrates, in the waters with significantly higher flow velocity, but in about twice lower conductivity and alkalinity compared to community with Ranunculuspseudofluitans. The latter was found in the river situated in the gypsum karst area covered by watertight clay, with waters of higher alkalinity, conductivity, concentration of calcium ions and rich in nitrogen compounds. Abundance of nutrients (concentration of total phosphorus and total nitrogen) negatively affected abundance of both Ranunculus species.
Epiphytes and hemi-epiphytes are important floristic, structural and functional components of tropical rainforests. Their specific responses to light, temperature and water conditions during seed germination allow them to coexist with tropical forest trees. Here we investigated the effects of temperature, red to far-red light ratio (R:FR ratio) and water stress on seed germination of Ficus virens in tropical seasonal rainforest in Southwest China. We used incubators to create required temperature regimes, polyester filters to produce R:FR ratio gradients and mannitol solutions to simulate water stress. It was found that seed germination of F. virens was inhibited in the simulated understory conditions, i.e., at lower temperature (22/23°C), especially when combined with the R:FR ratio of 0.25, for which the germination percentage was less than 20%. In contrast, the seed germination percentages in the simulated canopy environment (22/32°C) showed no significant difference between R:FR ratios, with an average seed germination percentage as high as 65.8%. Seed germination delayed and decreased along with increasing water stress and was completely inhibited at -2.5 MPa, which might suggest that it is a kind of adaptation for F. virens seeds to detect the rainy season as germination chance on the canopy. Therefore, our study revealed the physiological mechanism for F. virens to be able to adapt to canopy environment.
Stachys annua is a short-lived archaeophyte. In Poland it has been classified as threatened with extinction (VU). It prefers carbonate soils and occurs as a weed in cropped and stubble fields in traditionally farmed areas.
Study of the occurrence of Stachys annua in North-Eastern Poland was conducted in 2009–2012 at four sites where the species occupied a minimum area of 30 m2 and occurred at each stage of a 4-year crop rotation (spring cereals, winter cereals, tuber crops and stubble fields). The floristically richest communities (25–34 species) were established in unploughed stubble fields, regardless of the habitat conditions. Phytocenoses with S. annua included rare species as demonstrated by high values of floristic value index (FV ranges from 25 to 36). Principle Component Analysis and Spearman rank correlations between plant traits and habitat conditions pointed to soil pH as the factor which determined S. annua phenotypic variation, in particular its height and seed production. The greatest phenotypic variation was found on the alkaline habitat, rich in nitrogen. On the other hand, the cluster analysis showed that the studied populations of inert nitrogen-poor habitats were the most similar.
Electrophoretic analysis of storage proteins from S. annua seeds revealed a relatively high genetic similarity of studied populations which was reflected in the similarity coefficients — 0.76 and 0.61 by Dice and Jaccard, respectively. In the case of small or fragmented populations this poses a threat associated with inbreeding and genetic drift of S. annua, which indicates that populations of this species in the study area need to be protected from extinction.
The effect of meadow management type on selected population traits of the rare plant Angelica palustris was examined. The study was carried out in a regularly mown meadow (Plot I), an abandoned meadow with medium high plants (Plot II) and an abandoned meadow with high plants (Plot III) situated in southern Poland (Proszowice Plateau). Observations conducted in the years 2010 and 2011 showed greater abundance of A.palustris in Plot I than in Plots II and III. This pointed to the significance of disturbance caused by mowing, which creates gaps in the plant cover and litter layer that become safe sites for A.palustris seedling recruitment and their subsequent growth. In the abandoned meadows a diminishing share of vegetative individuals and a reduction in the number of flowering stems in generative individuals were found. The height of generative stems in the abandoned meadows was higher than in the mown one as a response to the height of neighbouring plants. The number of umbels per stem and number of umbellets per umbel were positively correlated with the height of the stem. In light of our investigations, it can be stated that regular mowing has a beneficial effect on the state of populations of A. palustris. On the other hand, the formation of highly productive generative stems with substantial numbers of inflorescences and infructescences in abandoned meadows may promote successful seed dispersal and an escape from an unfavourable site.
In this study, we chose 61 plots along three randomly placed transects in urban and natural areas to examine Paralaudakia caucasia habitat preferences. Ten habitat characteristics found to affect the lizard occurrence were recorded in both habitat types. Based on ANOVA, distance to farmland, height of vegetation cover, percentage of cover of human structures, and slope orientation are significantly different between presence and absence plots. Using Principal Component Analysis, we found that the distance to farmland was the main factor predicted species presence in natural habitats. In urban habitats, the percentage of human structures was more important than other factors in predicting P. caucasia presence. The species is more abundant in regions with a low percentage of human-made structures. Other informative factors for species presence were distance from farmland and distance between refuges for urban and natural populations, respectively. Urban populations of P. caucasia appear to prefer areas outside of the city center, far from human structures, whereas natural populations appear to prefer areas away from villages where they may find higher densities of safe refuges. Isolated rocks in both urban and natural areas have an important role in predicting species presence acting because they act as refuges.
We assess if survey of containers discarded by people (and collected within environmental cleanup actions) may be an useful method in detection of small mammal species and how different parameters of containers affect mammal mortality. The discarded containers without stoppers were collected from two sites (one forest and one agricultural) in western Poland. In 13 bottles (out of 288 collected containers), 58 specimens belonging to 10 species were found. Remains were found mostly in color glass bottles with mouth diameter 18–31 mm and 0.5–5.0 l capacity. We detected only six small mammal species during four short-term live-trapping sessions performed in the same sites. Thus, we suggest that the survey of discarded bottles may be an efficient complement to traditional scientific methods (as live-trapping), which can be performed by both specialists and amateurs, who, at the same time, would clean the environment of the ecological traps.
During laboratory studies on the reproductive biology of Valloniapulchella and V. costata we observed an unusual behaviour in adults and juveniles of both species. The snails moved with their heads and radulae over the egg surface as if feeding. The examination of the egg shell revealed the presence of the fungus Arthrobotrysoligospora, which commonly occurs in the soil and has multiple lifestyles: it is known as a nematode pathogen, a saprophyte and a coloniser of plant roots. The extraordinary behaviour of Vallonia may be associated with the presence of mycelium on the egg surface. We hypothesise three possible explanations of egg grooming: (1) parental care, (2) trophic behaviour and (3) the infection can constitute a means of defence against nematodes, which are known to be predators of snails and slugs as well as their eggs. The removal of the fungus is not associated with overcrowding, but may be a selective advantage when combined with feeding.
So far in Poland, the Asian clam Corbicula fluminea has been reported from the Oder (Odra) and Vistula River. Its new population has been discovered in the Warta-Gopło Canal in Konin (central Poland), where water temperature can reach 34°C, as the canal is a part of a power plant lake cooling system. The spatial distribution of C.fluminea was found to be very uneven and that is probably why this species was not found during earlier research. The highest density of C. fluminea was 78 ind.·m-2 at the site where water flow was the fastest (2.49 m·s-1), providing sufficient oxygenation of the water. The results suggest that existing information about the distribution of C.fluminea may be far from complete because the clam can be present also in the habitats that were not regarded as suitable for the species according to earlier reports, and therefore have not been monitored for its presence.
The aim of our study was to check whether maternal presence during the post-weaning period affects the onset of hibernation and weight gain under unlimited food supply in juvenile edible dormice Glis glis. We investigated four groups of siblings growing up in the presence of the mother (“with mother”; n=17) and three groups of juveniles separated from the mother after weaning (“without mother”, n = 17).
We found that: (i) more juveniles started hibernation from the group “without mother” than from the group “with mother” (χ2 = 8.24, P < 0.01) at the end of study, when most dams entered hibernation, (ii) weight was not a factor which determined the decision of entering hibernation (iii) juveniles growing up “without mother” did not differ significantly from juveniles raised “with mother” in terms of mean body mass during the last weighing before hibernation (t = 0.48, P = 0.63) and maximum body mass (t = 0.11, P = 0.91), (iv) the presence of the mother may influence the process of making decisions by juveniles about terminating activity and entering hibernation.
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