Meta-analysis of multidecadal biodiversity trends in Europe

Local biodiversity trends over time are likely to be decoupled from global trends, as local processes may compensate or counteract global change. We analyze 161 long-term biological time series (15–91 years) collected across Europe, using a comprehensive dataset comprising ~6,200 marine, freshwater and terrestrial taxa. We test whether (i) local long-term biodiversity trends are consistent among biogeoregions, realms and taxonomic groups, and (ii) changes in biodiversity correlate with regional climate and local conditions. Our results reveal that local trends of abundance, richness and diversity differ among biogeoregions, realms and taxonomic groups, demonstrating that biodiversity changes at local scale are often complex and cannot be easily generalized. However, we find increases in richness and abundance with increasing temperature and naturalness as well as a clear spatial pattern in changes in community composition (i.e. temporal taxonomic turnover) in most biogeoregions of Northern and Eastern Europe

Meta-analysis of multidecadal biodiversity trends in Europe

Local biodiversity trends over time are likely to be decoupled from global trends, as local processes may compensate or counteract global change. We analyze 161 long-term biological time series (15-91 years) collected across Europe, using a comprehensive dataset comprising similar to 6,200 marine, freshwater and terrestrial taxa. We test whether (i) local long-term biodiversity trends are consistent among biogeoregions, realms and taxonomic groups, and (ii) changes in biodiversity correlate with regional climate and local conditions. Our results reveal that local trends of abundance, richness and diversity differ among biogeoregions, realms and taxonomic groups, demonstrating that biodiversity changes at local scale are often complex and cannot be easily generalized. However, we find increases in richness and abundance with increasing temperature and naturalness as well as a clear spatial pattern in changes in community composition (i.e. temporal taxonomic turnover) in most biogeoregions of Northern and Eastern Europe. The global biodiversity decline might conceal complex local and group-specific trends. Here the authors report a quantitative synthesis of longterm biodiversity trends across Europe, showing how, despite overall increase in biodiversity metric and stability in abundance, trends differ between regions, ecosystem types, and taxa.peerReviewe

Spectrofluorimetric study of dissolved organic matter in River Salaca (Latvia) basin waters

Dissolved organic matter (DOM) in surface waters influences mineral weathering, nutrient cycling, aggregation of particulate matter and photochemical reactions in waters and aquatic communities. In this study, the effectiveness of UV and fluorescence measurements in distinguishing the origin of DOM and processes within the river basin were analyzed using the River Salaca basin as an example. The basin of River Salaca is characterized by low anthropogenic pressure, however, the water color during the last few decades has increased (an effect known as brownification). As tools to study the composition of dissolved organic substances in waters of the River Salaca and its tributaries the use of UV and fluorescence spectroscopy was evaluated. The use of the fluorescence index (a ratio of the emission intensity at a wavelength of 450 nm to that at 500 nm) allowed us to distinguish sources of aquatic DOM, characterize processes in the water body basin and to follow the changes in organic matter composition. Synchronous scan fluorescence spectrometry was more informative than excitation emission spectra and, provided information on the basic structural features of DOM

ЗАСТОСУВАННЯ НОВІТНЬОГО ІНТЕГРАЛЬНОГО ІНДЕКСУ ОКИСНОГО СТРЕСУ В ОЦІНЦІ ВПЛИВУ ДОВКІЛЛЯ НА ПРІСНОВОДНИХ МОЛЮСКІВ

The adverse environmental impacts cause the oxidative stress responsein the aquatic animals. However, depending on the severity and duration of impact, this response can be highly different. The aim of this study was the analysis of available results of the evaluation of antioxidant activities in the freshwater mollusks in the sense of the successfulness of the oxidative stress response. The recently proposed integrative index ‘Preparation to the oxidative stress’ (POS) was applied. Three populations of bivalve mollusks from the basin of the river Dniester were compared during three seasons, and in their ability to withstand heating (25o C and 30o C during 14 days) and exposure to ionizing radiation (14 days after the acute exposure to 2 mGy). The musselswere sampled in the low disturbed pristine site, highly polluted agricultural region and the cooling pond of the nuclear power plant with the constantly elevated temperature. The parameters for the calculation of POS included superoxide dismutase activity, catalase activity, glutathione S-transferase activity, glutathione concentration, and metallothionein (from its thiol groups) concentration. The values were calculated as the magnitude of change (as % change) in comparison to the corresponding control (less disturbed field group or non-exposed group). Three criteria for POS were applied. The number of the positive and negative changes and their limits were indicated. The analysis have shown that the POS responses were in the limits of adaptive ability in all studied cases. However, the results of POS calculation allowed the distinguishing of the responses that arerealized in the field and experimental exposures of mollusks.The most distinct responses were shown for the glutathione (mainly positive changes) whereas the metalothionein level was mainly oppressed, particularly under the heating. The depressive direction was estimated in the cases of extreme temperatures, irradiation and, mainly for the mollusks from the highly polluted sites. The key importance of POS as a survival strategy of the mussels exposed to adverse impact depending on the life historyis evident.</jats:p