Submerged macrophytes are of key importance for the structure and functioning of shallow lakes and can be decisive for maintaining them in a clear water state. The ongoing climate change affects the macrophytes through changes in temperature and precipitation, causing variations in nutrient load, water level and light availability. To investigate how these factors jointly determine macrophyte dominance and growth, we conducted a highly standardized pan-European experiment involving the installation of mesocosms in lakes. The experimental design consisted of mesotrophic and eutrophic nutrient conditions at 1 m (shallow) and 2 m (deep) depth along a latitudinal temperature gradient with average water temperatures ranging from 14.9 to 23.9°C (Sweden to Greece) and a natural drop in water levels in the warmest countries (Greece and Turkey). We determined percent plant volume inhabited (PVI) of submerged macrophytes on a monthly basis for 5 months and dry weight at the end of the experiment. Over the temperature gradient, PVI was highest in the shallow mesotrophic mesocosms followed by intermediate levels in the shallow eutrophic and deep mesotrophic mesocosms, and lowest levels in the deep eutrophic mesocosms. We identified three pathways along which water temperature likely affected PVI, exhibiting (a) a direct positive effect if light was not limiting; (b) an indirect positive effect due to an evaporation-driven water level reduction, causing a nonlinear increase in mean available light; and (c) an indirect negative effect through algal growth and, thus, high light attenuation under eutrophic conditions. We conclude that high temperatures combined with a temperature-mediated water level decrease can counterbalance the negative effects of eutrophic conditions on macrophytes by enhancing the light availability. While a water level reduction can promote macrophyte dominance, an extreme reduction will likely decrease macrophyte biomass and, consequently, their capacity to function as a carbon store and food source.

• Klíčová slova
• climate change, latitudinal gradient, macrophytes, mesocosm, nutrients, shallow lakes, water level, water temperature,
• MeSH
• jezera * MeSH
• teplota MeSH
• voda * MeSH
• živiny MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Švédsko MeSH
• Názvy látek
• voda * MeSH

Microplastics (MP) are being released into the environment at an increasing rate, causing extensive pollution in soils and affecting biota and processes. Although the use of biodegradable plastic has increased, its effects on the soil microbial community are not yet well understood. A controlled mesocosm experiment was conducted to investigate the response of soil microbial communities to increasing amounts of starch-polybutylene adipate terephthalate MPs (PBAT-BD-MPs) added to the soil. The experiment included microbes, earthworms, springtails, and plants. The PBAT-BD-MPs were added to the soil column at doses ranging from 0 to 0.8 % w/w of soil dry mass, and the columns were incubated for 11 weeks under controlled climatic conditions. Bacterial and fungal amplicon sequencing was used to investigate the dose-dependent response of the soil microbial communities' alpha and beta diversity. The alpha diversity indices of the bacterial and fungal communities increased with increasing PBAT-BD-MP concentration. Bacterial richness was highest at the highest MP concentration (0.8 %). A similar trend was observed in the fungal community, with a significant increase in fungal richness as PBAT-BD-MP concentration increased. The alpha diversity of both bacterial and fungal communities significantly increased in MP treatments compared to the control treatment. At the highest MP concentration (0.8 %), the abundance of the bacterial phylum Planctomycetes showed a significant increase, while Firmicutes showed a significant decrease. The abundance of the fungal phyla Ascomycota and Mortierellomycota also significantly increased at the highest PBAT-BD-MP concentration compared to the control group. Alongside changes in the soil microbial community, we observed a rise in soil respiration as the concentration of PBAT-BD-MPs increased. Our three-month mesocosm study demonstrates that the introduction of biodegradable microplastics into the natural standard soil environment in realistic concentrations (0-0.025-0.05-0.2-0.8 %) and particle size distribution alters the soil bacterial and fungal community.

• Klíčová slova
• Bacteria, CLIMECS, Fungi, Polybutylene adipate terephthalate PBAT, Soil respiration,
• MeSH
• Bacteria účinky léků   MeSH
• biodegradace MeSH
• biologicky odbouratelné plasty * MeSH
• houby účinky léků   MeSH
• látky znečišťující půdu * toxicita   MeSH
• mikrobiota * účinky léků   MeSH
• mikroplasty * toxicita   MeSH
• Oligochaeta MeSH
• půdní mikrobiologie * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• biologicky odbouratelné plasty * MeSH
• látky znečišťující půdu * MeSH
• mikroplasty * MeSH

Constructed wetlands (CWs) for pesticide mitigation from agricultural runoff became widespread in the last decade. However, comparison of different types of CWs at one location is missing. Therefore, site by site comparison of three different types (subsurface flow, surface flow and floating hydroponic root mat) of CWs treating four chloroacetanilide herbicides (acetochlor, s-metolachlor, metazachlor, dimethachlor) were carried out. All three planted systems are effective in removing the four herbicides with removal efficiency >92% after 9days. The metabolites ethane sulfonic acids (ESA) and oxanilic acids (OA) of the four herbicides peaked at 9days in the surface flow CWs with soil, but all the metabolites didn't peaked in the subsurface flow with gravel systems and the floating hydroponic root mat system after 21days. All the detected metabolites account about 20% of the mother compounds. There is no noticeable metabolites accumulation in the control system (no plants and no substrate), which indicate no microbial degradation taken place. Plant accumulation and soil adsorption are negligible for the removal of the four herbicides, which are <0.6%. In conclude, plants can enhance the removal of chloroacetanilide herbicides in all the CWs, and the floating hydroponic root mat is the most cost-efficient alternatives for chloroacetanilide herbicides removal due to the absence of substrate.

• Klíčová slova
• Acetochlor, Chloroacetanilide herbicides, Constructed wetland, Hydroponic root mat,
• MeSH
• acetamidy analýza   MeSH
• adsorpce MeSH
• chemické látky znečišťující vodu analýza   MeSH
• herbicidy analýza   MeSH
• mokřady * MeSH
• půda MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 2-chloro-N-(ethoxymethyl)-N-(2-methyl-6-(trifluoromethyl)phenyl)acetamide MeSH Prohlížeč
• acetamidy MeSH
• chemické látky znečišťující vodu MeSH
• herbicidy MeSH
• půda MeSH

Nutrient addition may change soil microbial community structure, but soil microbes must simultaneously contend with other, interacting factors. We studied the effect of soil type (peat, mineral), water level (low, high), and nutrient addition (unfertilized, fertilized) on wet grassland soil microbial community structure in both vegetated and un-vegetated soils after five years of treatment application in a mesocosm, using Illumina sequencing of the bacterial V4 region of the small ribosomal sub-units. Soil type, water level, and plant presence significantly affected the soil microbial structure, both singly and interactively. Nutrient addition did not directly impact microbiome structure, but acted indirectly by increasing plant biomass. The abundance of possible plant growth promoting bacteria and heterotrophic bacteria indicates the importance of bacteria that promote plant growth. Based on our results, a drier and warmer future would result in nutrient-richer conditions and changes to microbial community structure and total microbial biomass and/or abundances, with wet grasslands likely switching from areas acting as C sinks to C sources.

• Klíčová slova
• Carex acuta, context dependence, r/K strategies, soil microbial community structure, wet grasslands,
• MeSH
• Bacteria MeSH
• biomasa MeSH
• mikrobiota * MeSH
• pastviny * MeSH
• půda chemie   MeSH
• půdní mikrobiologie MeSH
• rostliny mikrobiologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• půda MeSH

Combining a minimum food web model with Arctic microbial community dynamics, we have suggested that top-down control by copepods can affect the food web down to bacterial consumption of organic carbon. Pursuing this hypothesis further, we used the minimum model to design and analyse a mesocosm experiment, studying the effect of high (+Z) and low (-Z) copepod density on resource allocation, along an organic-C addition gradient. In the Arctic, both effects are plausible due to changes in advection patterns (affecting copepods) and meltwater inputs (affecting carbon). The model predicts a trophic cascade from copepods via ciliates to flagellates, which was confirmed experimentally. Auto- and heterotrophic flagellates affect bacterial growth rate and abundance via competition for mineral nutrients and predation, respectively. In +Z, the model predicts low bacterial abundance and activity, and little response to glucose; as opposed to clear glucose consumption effects in -Z. We observed a more resilient bacterial response to high copepods and demonstrate this was due to changes in bacterial community equitability. Species able to use glucose to improve their competitive and/or defensive properties, became predominant. The observed shift from a SAR11-to a Psychromonodaceae - dominated community suggests the latter was pivotal in this modification of ecosystem function. We argue that this group used glucose to improve its defensive or its competitive abilities (or both). Adding such flexibility in bacterial traits to the model, we show how it creates the observed resilience to top-down manipulations observed in our experiment.

• MeSH
• autotrofní procesy MeSH
• Bacteria růst a vývoj   izolace a purifikace   metabolismus   MeSH
• Ciliophora fyziologie   MeSH
• Copepoda fyziologie   MeSH
• fyziologie bakterií * MeSH
• glukosa metabolismus   MeSH
• heterotrofní procesy MeSH
• mikrobiota MeSH
• potravní řetězec * MeSH
• uhlík metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Arktida MeSH
• Názvy látek
• glukosa MeSH
• uhlík MeSH

The ubiquitous presence of microplastics (MP) in aquatic ecosystems can affect organisms and communities in multiple ways. While MP research on aquatic organisms has primarily focused on marine ecosystems and laboratory experiments, the community-level effects of MP in freshwaters, especially in lakes, are poorly understood. To examine the impact of MP on freshwater lake ecosystems, we conducted the first in situ community-level mesocosm experiment testing the effects of MP on a model food web with zooplankton as main herbivores, odonate larvae as predators, and chironomid larvae as detritivores for seven weeks. The mesocosms were exposed to a mixture of the most abundant MP polymers found in freshwaters, added at two different concentrations in a single pulse to the water surface, water column and sediment. Water column MP concentrations declined sharply during the first two weeks of the experiment. Contrary to expectations, MP ingestion by zooplankton was low and limited mainly to large-bodied Daphnia, causing a decrease in biomass. Biomass of the other zooplankton taxa did not decrease. Presence of MP in the faecal pellets of odonate larvae that fed on zooplankton was indicative of a trophic transfer of MP. The results demonstrated that MP ingestion varies predictably with MP size, as well as body size and feeding preference of the organism, which can be used to predict the rates of transfer and further effects of MP on freshwater food webs. For chironomids, MP had only a low, short-term impact on emergence patterns while their wing morphology was significantly changed. Overall, the impact of MP exposure on the experimental food web and cross-ecosystem biomass transfer was lower than expected, but the experiment provided the first in situ observation of MP transfer to terrestrial ecosystems by emerging chironomids.

• Klíčová slova
• Chironomidae, Lake ecosystem, Microplastic, Odonata, Trophic transfer, Zooplankton,
• MeSH
• chemické látky znečišťující vodu * analýza   MeSH
• ekosystém MeSH
• jezera MeSH
• mikroplasty * MeSH
• plastické hmoty MeSH
• potravní řetězec MeSH
• voda MeSH
• zooplankton MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chemické látky znečišťující vodu * MeSH
• mikroplasty * MeSH
• plastické hmoty MeSH
• voda MeSH

Aggregated transfer factors (Tag) were identified for three common vegetables grown in six common European soils freshly contaminated by 134Cs and 85Sr. The experiment was carried out as a mesocosm experiment in pots with an average soil weight of 15.8 kg per pot. The vegetables were grown one after the other during one vegetation season, in the order lettuce, onion, and radish (the order usually applied in private gardens and small farms). Despite the fact that lettuce was grown in the most contaminated soil, it had the lowest Tag (in m2/kg) of both radionuclides (3.6E-4 for Cs, 2.0E-2 for Sr), while onion had 6.4E-3 for Cs and 3.2E-2 for Sr and radish had 1.9E-3 for Cs and 8.1E-2 for Sr. Potassium supply did not show any statistically significant effect on Cs Tag; there was a significant impact of K on the decrease in Sr Tag. The experiments indicated that Tag is more affected by plant species than by soil type; therefore, selection of plants with a lower capacity to uptake radionuclides may be an important measure to reduce food contamination and thus minimize the committed effective dose.

• Klíčová slova
• Caesium, Radionuclides, Soil, Strontium, Transfer factor, Vegetable,
• MeSH
• kontaminace potravin MeSH
• půda MeSH
• salát (hlávkový) MeSH
• zelenina * MeSH
• znečištění životního prostředí * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• půda MeSH

Constructed wetlands (CWs) are considered as low-cost and energy-efficient wastewater treatment systems. Media selection is one of the essential technical keys for their implementation. The purpose of this work was essentially to evaluate the removal efficiency of organic pollution and nitrogen from municipal wastewater (MWW) using different selected media (gravel/gravel amended with granulated cork) in mesocosm horizontal flow constructed wetlands (HFCWs). The results showed that the highest chemical oxygen demand (COD) and ammonium nitrogen removal of 80.53% and 42%, respectively, were recorded in the units filled with gravel amended with cork. The influence of macrophytes (Phragmites australis and Typha angustifolia) was studied and both species showed steeper efficiencies. The system was operated under different hydraulic retention times (HRTs) i.e., 6 h, 24 h, 30 h, and 48 h. The obtained results revealed that the COD removal efficiency was significantly enhanced by up to 38% counter to the ammonium rates when HRT was increased from 6 h to 48 h. Moreover, the removal efficiency of two endocrine-disrupting compounds (EDCs) namely, bisphenol A (BPA) and diclofenac (DCF) was investigated in two selected HFCWs, at 48 h HRT. The achieved results proved the high capacity of cork for BPA and DCF removal with the removal rates of 90.95% and 89.66%, respectively. The results confirmed the role of these engineered systems, especially for EDC removal, which should be further explored.

• Klíčová slova
• constructed wetlands, emerged substrates, endocrine-disrupting compounds, granulated cork, wastewater treatment,
• Publikační typ
• časopisecké články MeSH

Sludge drying bed (SDB) treatment is a valuable alternative to conventional sludge treatment methods. However, changes in sludge hydrotexture during dewatering present a barrier for direct modeling of the SDB process. This study proposes a modeling strategy to simulate the sludge stabilization process in SDB treatment by separating sludge dewatering and sludge solids stabilization into independent processes. Two cell decay theories widely used by activated sludge models (ASM), death-regeneration concept and endogenous respiration theory, are compared to describe the biokinetic processes of sludge digestion. Both cell decay theories are found to adequately describe effluent total COD, NH4-N, NO3-N, and sludge layer composition, but have pronounced differences in describing effluent COD compositions. Results show that natural aeration does not maintain adequate aerobic/anoxic sludge digestion within the sludge layer to fully nitrify NH4-N released by cell decay. Results also indicate that the kinetics of sludge digestion are adaptable over time, indicating the need to adopt lumped values for biokinetic simulations. While lowered sludge dewatering rates (outflow) can increase biodegradable COD for cell metabolism, increased sludge loading rates (inflow) lead to higher effluent COD and NH4-N concentrations. Contrary to conventional judgement, this study demonstrates the merit of sludge layer formation to reduce leaching loss of biodegradable COD. Overall, the proposed modeling strategy is proven capable of simulating deposited sludge digestion processes in an SDB.

• Klíčová slova
• Activated sludge models (ASM), Cell decay theory, Modeling, Sludge drying bed (SDB), Sludge treatment,
• MeSH
• bioreaktory MeSH
• kinetika MeSH
• odpad tekutý - odstraňování * MeSH
• odpadní vody * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• odpadní vody * MeSH

This study investigated the effects of arbuscular mycorrhizal fungi (AMF) colonization on the growth of wetland plants (Glyceria maxima), and treatment performance in constructed wetlands (CWs) under the stress of pharmaceuticals ibuprofen (IBU) and diclofenac (DCF). Results showed that the growth of G. maxima was significantly increased by AMF colonization. AMF significantly increased the activities of antioxidant enzymes (peroxidase and superoxide dismutase) and soluble protein content in wetland plants, but the contents of malondialdehyde and O2•- were reduced. The removal efficiencies of TOC, PO43--P, NH4+-N, and TN were increased in AMF+ treatments by 6%, 11%, 15% and 11%, respectively. AMF increased the removal efficiencies of IBU and DCF by 6-14% and 2-21%, respectively, and reduced the content of their metabolites (2-OH IBU, CA IBU and 4'-OH DCF) in the effluent. Besides, the presence of AMF increased the contents of IBU and DCF in plant roots, while decreased their transportation to shoots. AMF symbiosis decreased the contents of IBU metabolites (2-OH IBU and CA IBU) but increased the contents of DCF metabolite (4'-OH DCF) in the roots of the host plant. In conclusion, these results indicated that AMF plays a promising role in CWs for emerging pollutants removal.

• Klíčová slova
• Arbuscular mycorrhizal fungi, Constructed wetland, Diclofenac, Ibuprofen, Metabolites,
• MeSH
• diklofenak MeSH
• houby MeSH
• ibuprofen MeSH
• kořeny rostlin MeSH
• léčivé přípravky * MeSH
• mokřady MeSH
• mykorhiza * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• diklofenak MeSH
• ibuprofen MeSH
• léčivé přípravky * MeSH