Publications by authors named "Janice Brahney"

Atomic force microscopy-based infrared spectroscopy (AFM-IR) and optical photothermal infrared (O-PTIR) spectroscopy are cutting-edge techniques used for precise nanoscale chemical analysis, capable of detecting and characterizing particles smaller than 1 μm. In this study, we applied both techniques to analyze snow subsamples collected from Beaver Mountain, Utah. Quantification by AFM-IR identified a concentration of 1.

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The rise in global temperature and the increase in atmospheric transport and deposition of dust linked to greater aridity, land abandonment, and wildfires, are placing significant stress on freshwater microbial communities. Temperature increases and the nutrients contained in the dust may independently and together alter the metabolism and structure of these communities. However, dust chemistry is widely variable, and pre-existing lake conditions will likely influence the response of the algal and microbial communities to added nutrients and temperature stress.

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Plastic photodissolution into dissolved organic carbon (DOC) is a key proposed loss pathway for plastic in aquatic environments. However, the specific solar excitation wavelengths that drive photodissolution remain unknown, limiting our ability to model and predict photodissolution rates in natural aquatic environments. To better understand the impact of solar excitation wavelength on plastic photodissolution rates, we measured the wavelength sensitivity of photodissolution for a variety of transparent and semitransparent commercial and postconsumer plastic films with wide-spanning polymer chemistries.

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The ionic and nutrient composition of mountain lakes recovering from atmospheric acidification is increasingly influenced by climate change (increasing air temperature and frequency of heavy rainfall events). We investigated the evolution of organic nitrogen (ON), dissolved organic carbon (DOC) and phosphorus (P) concentrations in alpine lakes in the Tatra Mountains (Central Europe) between 1993 and 2023, resulting from changes in climate and the ionic composition of atmospheric deposition. Our results suggest that the decreasing acidity of precipitation and the climatically induced increasing frequency of heavy rainfall events and air temperatures fluctuating around the freezing point have the potential to increase ON concentrations in alpine lakes despite decreasing deposition of inorganic N.

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Wildfire activity is increasing globally. The resulting smoke plumes can travel hundreds to thousands of kilometers, reflecting or scattering sunlight and depositing particles within ecosystems. Several key physical, chemical, and biological processes in lakes are controlled by factors affected by smoke.

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Wildfires produce smoke that can affect an area >1000 times the burn extent, with far-reaching human health, ecologic, and economic impacts. Accurately estimating aerosol load within smoke plumes is therefore crucial for understanding and mitigating these impacts. We evaluated the effectiveness of the latest Collection 6.

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Oligotrophic mountain lakes act as sensitive indicators of landscape-scale changes in mountain regions due to their low nutrient concentration and remote, relatively undisturbed watersheds. Recent research shows that phosphorus (P) concentrations are increasing in mountain lakes around the world, creating more mesotrophic states and altering lake ecosystem structure and function. The relative importance of atmospheric deposition and climate-driven changes to local biogeochemistry in driving these shifts is not well established.

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Aquatic communities are increasingly subjected to multiple stressors through global change, including warming, pH shifts, and elevated nutrient concentrations. These stressors often surpass species tolerance range, leading to unpredictable consequences for aquatic communities and ecosystem functioning. Phytoplankton, as the foundation of the aquatic food web, play a crucial role in controlling water quality and the transfer of nutrients and energy to higher trophic levels.

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Microplastics have emerged as an important threat to terrestrial ecosystems. To date, little research has been conducted on investigating the effects of microplastics on ecosystem functions and multifunctionality. In this study, we conducted the pot experiments containing five plant communities consisting of Phragmites australis, Cynanchum chinense, Setaria viridis, Glycine soja, Artemisia capillaris, Suaeda glauca, and Limonium sinense and added polyethylene (PE) and polystyrene (PS) microbeads to the soil (contained a mixture of 1.

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Reliable quantitative information on sediment sources to rivers is critical to mitigate contamination and target conservation and restoration actions. However, for large-scale river basins, determination of the relative importance of sediment sources is complicated by spatiotemporal variability in erosional processes and sediment sources, heterogeneity in sediment transport and deposition, and a paucity of sediment monitoring data. Sediment source fingerprinting is an increasingly adopted field-based technique that identifies the nature and relative source contribution of sediment transported in waterways.

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Wetland plants tolerate potentially hazardous metals through a variety of strategies, including exclusion or accumulation. Whether plants sequester metals and where they store them in their tissues is important for understanding the potential role of plants as remediators or vectors of metals to terrestrial food webs. Here we evaluate metal sequestration in Great Salt Lake wetlands for one invasive (Phragmites australis; phragmites) and three native plant species, i.

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We combine observations from Western USA and inverse modelling to constrain global atmospheric emissions of microplastics (MPs) and microfibers (MFs). The latter are used further to model their global atmospheric dynamics. Global annual MP emissions were calculated as 9.

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Asian dust comprises a large portion of the northern hemisphere atmospheric dust load, thereby exerting substantial influence on the Earth's climate, global biogeochemistry and hydrological cycle through accelerated snow and ice melt. Dust deposited on alpine glaciers encodes information on broad scale atmospheric-environmental processes. The (U/U) values of dust fine particulates can reflect the comminuting time and intermediate processes; thus, it provides a new method for the provenance of aeolian dust in the glacial snowpack/cryoconite.

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Increased nitrogen (N) deposition rates over the past century have affected both North American and European mountain lake ecosystems. Ecological sensitivity of mountain lakes to N deposition varies, however, because chemical and biological responses are modulated by local watershed and lake properties. We evaluated predictors of mountain lake sensitivity to atmospheric N deposition across North American and European mountain ranges and included as response variables dissolved inorganic N (DIN = NNH + NNO) concentrations and phytoplankton biomass.

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Human agriculture, wastewater, and use of fossil fuels have saturated ecosystems with nitrogen and phosphorus, threatening biodiversity and human water security at a global scale. Despite efforts to reduce nutrient pollution, carbon and nutrient concentrations have increased or remained high in many regions. Here, we applied a new ecohydrological framework to ~12,000 water samples collected by the U.

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Large areas of arid regions in the Tibetan Plateau (TP) are undergoing desertification and subsequent aeolian emission and transport. The contribution of TP soils to the atmospheric aerosol burden in Asia and elsewhere is not known. Here, we use Hf, Nd, and Sr isotopes to distinguish the TP from other Asian dust-producing regions and compare the signatures to sediments in major dust sink regions.

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Plastic pollution is one of the most pressing environmental and social issues of the 21st century. Recent work has highlighted the atmosphere's role in transporting microplastics to remote locations [S. Allen et al.

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Article Synopsis
  • Non-point source (NPS) pollution persists in many watersheds despite reduction efforts, and beaver activity transforms flowing streams into slower, sediment-trapping ponds which can mitigate these pollutants.
  • The study examined how nutrients and metals behave in beaver ponds of varying ages by sampling water quality and sediment concentrations across different seasons.
  • Findings indicate that while older and younger ponds show little impact on dissolved nutrients, mid-aged ponds significantly reduce nitrogen levels in summer and suggest that beaver ponds may initially sequester phosphorus effectively before acting as a minor source later on.
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Alpine regions are changing rapidly due to loss of snow and ice in response to ongoing climate change. While studies have documented ecological responses in alpine lakes and streams to these changes, our ability to predict such outcomes is limited. We propose that the application of fundamental rules of life can help develop necessary predictive frameworks.

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Crucial to the successful conservation of endangered species is the overlap of their ranges with protected areas. We analyzed protected areas in the continental USA to assess the extent to which they covered the ranges of endangered tetrapods. We show that in 80% of ecoregions, protected areas offer equal (25%) or worse (55%) protection for species than if their locations were chosen at random.

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Eleven billion metric tons of plastic are projected to accumulate in the environment by 2025. Because plastics are persistent, they fragment into pieces that are susceptible to wind entrainment. Using high-resolution spatial and temporal data, we tested whether plastics deposited in wet versus dry conditions have distinct atmospheric life histories.

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In the United States, the Clean Water Act (CWA) establishes water quality standards important for maintaining healthy freshwater ecosystems. Within the CWA framework, states define their own water quality criteria, leading to a potential fragmentation of standards between states. This fragmentation can influence the management of shared water resources and produce spillover effects of pollutants crossing state lines and other political boundaries.

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We describe continental-scale increases in lake and stream total phosphorus (TP) concentrations, identified through periodic probability surveys of thousands of water bodies in the conterminous U.S. The increases, observed over the period 2000-2014 were most notable in sites in relatively undisturbed catchments and where TP was initially low (e.

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