The study aimed to recognize whether the activity of a semi-aquatic invasive carnivore – the American mink Neovison vison – is related to the distribution of waterbird colonies. For this reason, we monitored mink occurrence in lake reedbeds and the fate of artificial nests imitating those of the great crested grebe Podiceps cristatus. The location of artificial nests in the grebe colony increased the probability of their survival compared to those placed outside the grebe colony. During the study, mink activity increased over time. In general, it was lower in colonies than outside of them, suggesting that the presence of natural nests does not increase the probability of mink occurrence in lake reedbeds. However, mink activity was negatively correlated with the distance from the lake shoreline and differed spatially according to the presence or absence of natural grebe nests. In grebe colonies, the probability of mink occurrence at greater distances from the lake shoreline was higher than outside, which can be explained by optimizing swimming effort while searching for prey. In conclusion, mink activity in colonies was lower than in areas with no waterbird nests, and nest location in a colony decreased predation risk by mink.
Photosynthesis, as a fundamental element in the life process, is integrated in the evolution of living systems on the basis of hydrogen cycles on various hierarchic levels. Conversion of radiant energy enables the oxidation of water, whereby free oxygen accumulates in the atmosphere. Hydrogen is (reversibly) stored in organic materials formed under reductive CO2-fixation and by the incorporation of the other elements, which are necessary for living systems. All endergonic processes in living cells are finally driven by the energy released through the clean recombination of protons and electrons with oxygen to water. Duration of the stored energy and the complexity of the systems thus produced is correlated negatively with the conversion efficiency of the radiation energy. Entropy is a unifying principle in the evolution of living systems, inclusive human societies.
In mammalian carnivore guilds (order Carnivora), spatiotemporal partitions play a major role in reducing competitive confrontations and facilitating successful sympatry. Using camera-trapping techniques, the present study aimed to elucidate patterns of spatial distribution and diel activities among medium- and large-sized carnivore species across central Bulgaria. We obtained 3,364 images of nine focal carnivores from 13,988 camera-trapping days between 2015 and 2020. Our findings indicated that the spatial distribution of the focal carnivore guilds varied with changes in altitudinal gradient, ruggedness, and forest-agricultural landscape changes. Specifically, the two largest species, the grey wolf (Canis lupus Linnaeus, 1758) and the brown bear (Ursus arctos Linnaeus, 1758), were found only in the Balkan Mountains, whereas the largest mesocarnivore, the golden jackal (Canis aureus Linnaeus, 1758), was mainly distributed agricultural lowlands. The European wildcat (Felis sylvestris Schreber, 1777) was found in forests inside protected areas, and other mesocarnivores were distributed at intermediate levels between wooded-mountains and agricultural lowlands. Brown bear, golden jackal, and domestic dog (Canis lupus familiaris Linnaeus, 1758) showed cathemeral, crepuscular, and diurnal activity, respectively, whereas the remaining six carnivores showed nocturnal activity in synchrony with their main prey. Our findings indicated that anthropogenic landscape modifications and potential interspecific competition resulted in patterns of spatial distribution and temporal activity in this carnivore guild.
The history of the journals "Photosynthetica" and "Photosynthesis Research" is traced from its beginning. Their development is related to the history of several publishers (Dr W. Junk Publishers, Martinus Nijhoff, Kluwer Academic Publishers). This account is based on recollections and records of the authors, Ad C. Plaizier, and René Marcelle (the first Editor-in-Chief of Photosynthesis Research). and Govindjee, Z. Šesták, W. R. Peters.
In a recent study, we showed how local-scale climate change impacts (increased temperature, reduced rainfall, shifts in peak rainfall) affected the hydrology of a channelised lowland European river (reduced flow, reduction in flood events, increased siltation, macrophyte growth), allowing native fish species to recolonise the bankside zone and reduce the density of invasive round goby Neogobius melanostomus by effectively removing its preferred habitat, rip-rap bank stabilisation. Here, we report on a follow-on study whereby stretches of the newly vegetated bank were stripped back to clean rip-rap to assess whether presence/absence of rip-rap was the major factor affecting non-gobiid, tubenose goby Proterorhinus semilunaris and round goby abundance. Our results confirmed rip-rap as a major factor increasing round goby abundance, and hence invasion success, on European rivers, while vegetated banks saw an increase in the abundance and diversity of non-gobiid species. While tubenose gobies showed no preference for habitat type, their numbers were significantly reduced in rip-rap colonised by larger and more aggressive round gobies. We discuss our results in light of recent artificial bank restoration measures undertaken on the Danube and Rhine and the potential role of round goby as a flagship species for cost-effective, large scale river bank restoration projects with multiple ecosystem benefits.
The paper evaluates changes in the water temperature of the Vistula River – one of the longest rivers in Europe. Mean monthly and annual water temperatures from the period 1971–2017 for 11 stations along the entire length of the river revealed the increasing trends. The mean increase in water temperature in the analysed multi-annual period was 0.31 °C dec–1. In the majority of analysed stations, the key factor determining changes in the water temperature of the river was air temperature. The observed water warming in the Vistula River should be considered an exceptionally unfavourable situation in the context of importance of water temperature for a number of processes and phenomena occurring in river ecosystems. Given the scale of changes, fast measures should be undertaken to slow down the warming.