Nitrate source apportionment and risk assessment: A study in the largest ion-adsorption rare earth mine in China.

Nitrate (NO) pollution in water bodies has received widespread attention, but studies on nitrogen transformation and pollution risk assessment are still limited, especially in rare earth mining areas. In this study, surface and groundwater samples were collected from the largest rare earth mining site in southern China, and analyzed for the hydrochemical and stable isotopic characteristics. The results showed that the NO concentrations ranged from 1.

Effects of Nitrogen Input on Community Structure of the Denitrifying Bacteria with Nitrous Oxide Reductase Gene (nosZ I): a Long-Term Pond Experiment.

Excessive nitrogen (N) input is an important factor influencing aquatic ecosystems and has received increasing public attention in the past decades. It remains unclear how N input affects the denitrifying bacterial communities that play a key role in regulating N cycles in various ecosystems. To test our hypothesis-that the abundance and biodiversity of denitrifying bacterial communities decrease with increasing N-we compared the abundance and composition of denitrifying bacteria having nitrous oxide reductase gene (nosZ I) from sediments (0-20 cm) in five experimental ponds with different nitrogen fertilization treatment (TN10, TN20, TN30, TN40, TN50) using quantitative PCR and pyrosequencing techniques.

Aquaculture drives distinct patterns of planktonic and sedimentary bacterial communities: insights into co-occurrence pattern and assembly processes.

Aquaculture would change the environmental condition in the lake ecosystem, affecting the structure and function of the aquatic ecosystem. However, little is known about the underlying mechanisms controlling the distribution patterns of bacterial community respond to aquaculture in water column and sediment. Here, we investigated the composition, co-occurrence patterns, and assembly processes of planktonic and sedimentary bacterial communities (PBC vs.

Freshwater salinisation: a research agenda for a saltier world.

The widespread salinisation of freshwater ecosystems poses a major threat to the biodiversity, functioning, and services that they provide. Human activities promote freshwater salinisation through multiple drivers (e.g.

Regime shifts in a shallow lake over 12 years: Consequences for taxonomic and functional diversities, and ecosystem multifunctionality.

Under increasing nutrient loading, shallow lakes may shift from a state of clear water dominated by submerged macrophytes to a turbid state dominated by phytoplankton or a shaded state dominated by floating macrophytes. How such regime shifts mediate the relationship between taxonomic and functional diversities (FD) and lake multifunctionality is poorly understood. We employed a detailed database describing a shallow lake over a 12-year period during which the lake has displayed all the three states (clear, turbid and shaded) to investigate how species richness, FD of fish and zooplankton, ecosystem multifunctionality and five individual ecosystem functions (nitrogen and phosphorus concentrations, standing fish biomass, algae production and light availability) differ among states.

Responses of coastal sediment phosphorus release to elevated urea loading.

Increased urea is one of the common nitrogen forms polluting coastal waters and affecting nutrient dynamics. To investigate the effects of urea on sediment phosphorus (P) release, we carried out a 2-month mesocosm experiment with six targeted loadings of urea (0-0.6 mg N L d).

Community-level and function response of photoautotrophic periphyton exposed to oxytetracycline hydrochloride.

Periphyton is considered important for removal of organic pollutants from water bodies, but knowledge of the impacts of antibiotics on the community structure and ecological function of waterbodies remains limited. In this study, the effects of oxytetracycline hydrochloride (OTC) on the communities of photoautotrophic epilithon and epipelon and its effect on nitrogen and phosphorus concentrations in the water column were studied in a 12-day mesocosm experiment. The dynamics of nitrogen and phosphorus concentrations in the epipelon and epilithon experiment showed similar patterns.

Submersed macrophyte restoration with artificial light-emitting diodes: A mesocosm experiment.

Urban lakes are important natural assets but are exposed to multiple stressors from human activities. Submersed macrophytes, a key plant group that helps to maintain clear-water conditions in lakes, tend to be scarce in urban lakes, particularly when they are eutrophic or hypertrophic, and their loss is linked, in part, to impaired underwater light climate. We tested if enhancing the underwater light conditions using light-emitting diodes (LEDs) could restore submersed macrophytes in urban lakes.

Decreased spatial variation and deterministic processes of bacterial community assembly in the rhizosphere of Phragmites australis across the Middle-Lower Yangtze plain.

Comparison of the spatial distribution and assembly processes between bulk and rhizosphere bacterial communities at multiple spatial scales is vital for understanding the generation and maintenance of microbial diversity under the influence of plants. However, biogeographical patterns and the underlying mechanisms of microbial communities in bulk and rhizosphere sediments of aquatic ecosystems remain unclear. Here, we collected 140 bulk and rhizosphere sediment samples of Phragmites australis from 14 lakeshore zones across a 510-km transect in the Middle-Lower Yangtze plain.

Periphyton biomass and life-form responses to a gradient of discharge in contrasting light and nutrients scenarios in experimental lowland streams.

Climate-induced changes in precipitation and land-use intensification affect the discharge of streams worldwide, which, together with eutrophication and loss of riparian canopy, can affect periphyton biomass and composition, and therefore, ultimately the stream functioning. We investigated the responses of periphyton biomass and life-forms (i.e.

Logic and in-memory computing achieved in a single ferroelectric semiconductor transistor.

Exploring materials with multiple properties who can endow a simple device with integrated functionalities has attracted enormous attention in the microelectronic field. One reason is the imperious demand for processors with continuously higher performance and totally new architecture. Combining ferroelectric with semiconducting properties is a promising solution.

Trustworthy faces make people more risk-tolerant: The effect of facial trustworthiness on risk decision-making under gain and loss conditions.

People can judge a stranger's trustworthiness at first glance solely based on facial appearance. Moreover, the trust behaviors people exhibit toward strangers differ depending on perceived trustworthiness from faces. Research has found that people have different risk preferences according to the gain or loss frame.

Coupled effects of landscape structures and water chemistry on bacterioplankton communities at multi-spatial scales.

Bacterioplankton communities in rivers are strongly influenced by the surrounding landscape, yet the relationships between land use and bacterioplankton communities at multi-spatial scales and the mechanisms that shape bacterioplankton communities remain unclear. Here, we collected surface water samples from 14 tributaries of the Yuan River, a secondary tributary of the Yangtze River, which has been heavily impacted by human activities. We characterized the bacterioplankton communities by high-throughput sequencing techniques, and managed to identify the mechanisms governing bacterioplankton community assembly.

Impacts of climate change on water resources in the major countries along the Belt and Road.

Background: Climate change has altered global hydrological cycles mainly due to changes in temperature and precipitation, which may exacerbate the global and regional water shortage issues, especially in the countries along the Belt and Road (B&R).

Methods: In this paper, we assessed water supply, demand, and stress under three climate change scenarios in the major countries along the Belt and Road. We ensembled ten Global Climate Model (GCM) runoff data and downscaled it to a finer resolution of 0.

Decreasing toxicity of un-ionized ammonia on the gastropod Bellamya aeruginosa when moving from laboratory to field scale.

Along with a steady increasing use of artificial nitrogen fertilizer, concerns have been raised about the effects that high nitrogen loading may have on ecosystems. Due to the toxicity of unionized ammonia (NH), tolerance criteria have been proposed for ambient water management in many countries; however, these are mainly based on acute or chronic tests carried out under lab conditions run with purified water. Aiming at understanding the responses of organisms to natural exposure to high ammonia concentrations, a Viviparidae gastropod, Bellamya aeruginosa, was tested at three experimental scales: standard 96-h lab test, one-month cage test in 6 experimental ponds with continuous nitrogen inputs, and intensive investigation of the B.

Cascading effects of benthic fish impede reinstatement of clear water conditions in lakes: A mesocosm study.

In shallow eutrophic lakes, submersed macrophytes are essential for maintaining a clear water state, and they are affected markedly by fishes directly through herbivory and indirectly by fish-invertebrate-periphyton complexity, a pathway that presently is not well understood in subtropical lakes but probably vital to lake managements. We conducted a mesocosm study involving benthic fish (Misgurnus anguillicaudatus), snails (Radix swinhoei) and submersed macrophyte (Vallisneria natans), aiming to examine whether benthic fish is detrimental to reestablishment of clear-water macrophyte-dominated state in eutrophic degraded lakes. In addition, we aimed to investigate the cascading effect that benthic fish might have on periphyton and phytoplankton and to what extent snails can alleviate this effect.

From unusual suspect to serial killer: Cyanotoxins boosted by climate change may jeopardize megafauna.

The recent mass mortality event of more than 330 African elephants in Botswana has been attributed to biotoxins produced by cyanobacteria; however, scientific evidence for this is lacking. Here, by synthesizing multiple sources of data, we show that, during the past decades, the widespread hypertrophic waters in Southern Africa have entailed an extremely high risk and frequent exposure of cyanotoxins to the wildlife within this area, which functions as a hotspot of mammal species richness. The hot and dry climatic extremes have most likely acted as the primary trigger of the recent and perhaps also of prehistoric mass mortality events.

High-resolution reconstruction of typhoon events since ~1850 CE based on multi-proxy sediment records in a coastal lagoon, South China.

Coastal lagoon sediments provide continuous and high-resolution records of the activity of past typhoons. In this study, multiple proxies were analyzed with a core taken from Pinqing Lagoon located on the northeast margin of the South China Sea. Based on Pb dating, grain sizes and other geophysical/geochemical analyses, a total of seven typhoon-induced layers covering the past ~170 years were identified and compared with observational and historical records of typhoons.

Effects of DOC addition from different sources on phytoplankton community in a temperate eutrophic lake: An experimental study exploring lake compartments.

A mesocosm experiment was conducted in a temperate eutrophic lake with the hypotheses: 1) the addition of a labile form of DOC would trigger a more pronounced response in phytoplankton biomass and composition compared with a non-labile form; 2) DOC addition would increase phytoplankton biomass by co-inserting organic nutrients for phytoplankton growth; 3) DOC addition would change phytoplankton composition, in particular towards mixotrophic taxa due to higher DOC availability; and that 4) there would be differences in phytoplankton responses to DOC addition, depending on whether sediment was included or not. We used two types of mesocosms: pelagic mesocosms with closed bottom, and benthic mesocosms open to the sediment. The experiment ran for 29 days in total.

Perceiving the facial trustworthiness: Facial age, emotional expression, and attractiveness.

People can make trustworthiness judgements based on facial characteristics. However, the previous findings regarding whether facial age influences interpersonal trust are inconsistent. Using the trust game, the current study investigated the interactions of facial age with attractiveness and emotional expression in regard to trustworthiness judgements.

Biodegradable dissolved organic carbon shapes bacterial community structures and co-occurrence patterns in large eutrophic Lake Taihu.

Interactions between dissolved organic matter (DOM) and bacteria are central in the biogeochemical cycles of aquatic ecosystems; however, the relative importance of biodegradable dissolved organic carbon (BDOC) compared with other environmental variables in structuring the bacterial communities needs further investigation. Here, we investigated bacterial communities, chromophoric DOM (CDOM) characteristics and physico-chemical parameters as well as examined BDOC via bioassay incubations in large eutrophic Lake Taihu, China, to explore the importance of BDOC for shaping bacterial community structures and co-occurrence patterns. We found that the proportion of BDOC (%BDOC) correlated significantly and positively with the DOC concentration and the index of the contribution of recent produced autochthonous CDOM (BIX).

Small-sized omnivorous fish induce stronger effects on food webs than warming and eutrophication in experimental shallow lakes.

Warming, eutrophication, and increased omnivory by small-sized fish are global change processes that induce major effects on the food web structure and primary producers of shallow lakes. Despite the key relevance of phytoplankton and periphyton in freshwaters, the combined and potential synergistic effects of fish omnivory, warming and eutrophication, especially on periphyton, remains little addressed, particularly for subtropical shallow lakes. We experimentally tested the food web effects on phytoplankton and periphyton induced by small visually feeding omnivorous fish (Rhodeus ocellatus), high nutrient enrichment and warming (+4.