EandS Environmental Chemistry Inc.

Corvallis, OR, United States

EandS Environmental Chemistry Inc.

Corvallis, OR, United States
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McDonnell T.C.,E and S Environmental Chemistry Inc. | Belyazid S.,Belyazid Consulting and Communication AB | Sullivan T.J.,E and S Environmental Chemistry Inc. | Sverdrup H.,Lund University | And 2 more authors.
Environmental Pollution | Year: 2014

To evaluate potential long-term effects of climate change and atmospheric nitrogen (N) deposition on subalpine ecosystems, the coupled biogeochemical and vegetation community competition model ForSAFE-Veg was applied to a site at the Loch Vale watershed of Rocky Mountain National Park, Colorado. Changes in climate and N deposition since 1900 resulted in pronounced changes in simulated plant species cover as compared with ambient and estimated future community composition. The estimated critical load (CL) of N deposition to protect against an average future (2010-2100) change in biodiversity of 10% was between 1.9 and 3.5 kg N ha-1 yr-1. Results suggest that the CL has been exceeded and vegetation at the study site has already undergone a change of more than 10% as a result of N deposition. Future increases in air temperature are forecast to cause further changes in plant community composition, exacerbating changes in response to N deposition alone. © 2013 Elsevier Ltd. All rights reserved.

Sverdrup H.,Lund University | McDonnell T.C.,E and S Environmental Chemistry Inc. | Sullivan T.J.,E and S Environmental Chemistry Inc. | Nihlgard B.,Lund University | And 5 more authors.
Water, Air, and Soil Pollution | Year: 2012

The ForSAFE-VEG model was used to estimate atmospheric nitrogen deposition and climate effects on soil chemistry and ground vegetation in alpine and subalpine zones of the northern and central Rocky Mountains region in the USA from 1750 to 2500. Model simulations for a generalized site illustrated how the critical load of atmospheric nitrogen deposition could be estimated to protect plant biodiversity. The results appear reasonable compared with past model applications in northern Europe. Atmospheric N deposition critical loads estimated to protect plant biodiversity were 1 to 2 kg N/ha/year. This range could be greater, depending on the values selected for critical sitespecific parameters (precipitation, temperature, soil chemistry, plant nutrient uptake, and any eventual harvest of biomass) and the amount of biodiversity change allowed. © Springer Science+Business Media B.V. 2011.

McDonnell T.C.,EandS Environmental Chemistry Inc. | Cosby B.J.,University of Virginia | Sullivan T.J.,EandS Environmental Chemistry Inc.
Environmental Pollution | Year: 2012

Estimation of base cation supply from mineral weathering (BC w) is useful for watershed research and management. Existing regional approaches for estimating BC w require generalized assumptions and availability of stream chemistry data. We developed an approach for estimating BC w using regionally specific empirical relationships. The dynamic model MAGIC was used to calibrate BC w in 92 watersheds distributed across three ecoregions. Empirical relationships between MAGIC-simulated BC w and watershed characteristics were developed to provide the basis for regionalization of BC w throughout the entire study region. BC w estimates extracted from MAGIC calibrations compared reasonably well with BC w estimated by regression based on landscape characteristics. Approximately one-third of the study region was predicted to exhibit BC w rates less than 100 meq/m 2/yr. Estimates were especially low for some locations within national park and wilderness areas. The regional BC w results are discussed in the context of critical loads (CLs) of acidic deposition for aquatic ecosystem protection. © 2011 Elsevier Ltd. All rights reserved.

McDonnell T.C.,E and S Environmental Chemistry Inc. | Cosby B.J.,University of Virginia | Sullivan T.J.,E and S Environmental Chemistry Inc. | McNulty S.G.,U.S. Department of Agriculture | Cohen E.C.,U.S. Department of Agriculture
Environmental Pollution | Year: 2010

The critical load (CL) of acidic atmospheric deposition represents the load of acidity deposited from the atmosphere to the earth's surface at which harmful acidification effects on sensitive biological receptors are thought to occur. In this study, the CL for forest soils was estimated for 27 watersheds throughout the United States using a steady-state mass balance approach based on both national and site-specific data and using different approaches for estimating base cation weathering. Results suggested that the scale and source of input data can have large effects on the calculated CL and that the most important parameter in the steady-state model used to estimate CL is base cation weathering. These results suggest that the data and approach used to estimate weathering must be robust if the calculated CL is to be useful for its intended purpose. © 2010 Elsevier Ltd. All rights reserved.

Nierzwicki-Bauer S.A.,Rensselaer Polytechnic Institute | Boylen C.W.,Rensselaer Polytechnic Institute | Eichler L.W.,Rensselaer Polytechnic Institute | Harrison J.P.,Rensselaer Polytechnic Institute | And 8 more authors.
Environmental Science and Technology | Year: 2010

The Adirondack Mountains in New York State have a varied surficial geology and chemically diverse surface waters that are among the most impacted by acid deposition in the U.S. No single Adirondack investigation has been comprehensive in defining the effects of acidification on species diversity, from bacteria through fish, essential for understanding the full impact of acidification on biota. Baseline midsummer chemistry and community composition are presented for a group of chemically diverse Adirondack lakes. Species richness of all trophic levels except bacteria is significantly correlated with lake acid?base chemistry. The loss of taxa observed per unit pH was similar: bacterial genera (2.50), bacterial classes (1.43), phytoplankton (3.97), rotifers (3.56), crustaceans (1.75), macrophytes (3.96), and fish (3.72). Specific pH criteria were applied to the communities to define and identify acid-tolerant (pH < 5.0), acid-resistant (pH 5.0-5.6), and acid-sensitive (pH > 5.6) species which could serve as indicators. Acid-tolerant and acid-sensitive categories are at end-points along the pH scale, significantly different at P < 0.05; the acid-resistant category is the range of pH between these end-points, where community changes continually occur as the ecosystem moves in one direction or another. The biota acid tolerance classification (batc) system described herein provides a clear distinction between the taxonomic groups identified in these subcategories and can be used to evaluate the impact of acid deposition on different trophic levels of biological communities. © 2010 American Chemical Society.

Sullivan T.J.,EandS Environmental Chemistry Inc. | Cosby B.J.,University of Virginia | Driscoll C.T.,Syracuse University | McDonnell T.C.,EandS Environmental Chemistry Inc. | And 2 more authors.
Water Resources Research | Year: 2012

The dynamic watershed acid-base chemistry model of acidification of groundwater in catchments (MAGIC) was used to calculate target loads (TLs) of atmospheric sulfur and nitrogen deposition expected to be protective of aquatic health in lakes in the Adirondack ecoregion of New York. The TLs were calculated for two future dates (2050 and 2100) and three levels of protection against lake acidification (acid neutralizing capacity (ANC) of 0, 20, and 50 eq L -1). Regional sulfur and nitrogen deposition estimates were combined with TLs to calculate exceedances. Target load results, and associated exceedances, were extrapolated to the regional population of Adirondack lakes. About 30% of Adirondack lakes had simulated TL of sulfur deposition less than 50 meq m -2 yr to protect lake ANC to 50 eq L -1. About 600 Adirondack lakes receive ambient sulfur deposition that is above this TL, in some cases by more than a factor of 2. Some critical criteria threshold values were simulated to be unobtainable in some lakes even if sulfur deposition was to be decreased to zero and held at zero until the specified endpoint year. We also summarize important lessons for the use of target loads in the management of acid-impacted aquatic ecosystems, such as those in North America, Europe, and Asia. Copyright 2012 by the American Geophysical Union.

Povak N.A.,U.S. Department of Agriculture | Hessburg P.F.,U.S. Department of Agriculture | Reynolds K.M.,U.S. Department of Agriculture | Sullivan T.J.,EandS Environmental Chemistry Inc. | And 2 more authors.
Water Resources Research | Year: 2013

In many industrialized regions of the world, atmospherically deposited sulfur derived from industrial, nonpoint air pollution sources reduces stream water quality and results in acidic conditions that threaten aquatic resources. Accurate maps of predicted stream water acidity are an essential aid to managers who must identify acid-sensitive streams, potentially affected biota, and create resource protection strategies. In this study, we developed correlative models to predict the acid neutralizing capacity (ANC) of streams across the southern Appalachian Mountain region, USA. Models were developed using stream water chemistry data from 933 sampled locations and continuous maps of pertinent environmental and climatic predictors. Environmental predictors were averaged across the upslope contributing area for each sampled stream location and submitted to both statistical and machine-learning regression models. Predictor variables represented key aspects of the contributing geology, soils, climate, topography, and acidic deposition. To reduce model error rates, we employed hurdle modeling to screen out well-buffered sites and predict continuous ANC for the remainder of the stream network. Models predicted acid-sensitive streams in forested watersheds with small contributing areas, siliceous lithologies, cool and moist environments, low clay content soils, and moderate or higher dry sulfur deposition. Our results confirmed findings from other studies and further identified several influential climatic variables and variable interactions. Model predictions indicated that one quarter of the total stream network was sensitive to additional sulfur inputs (i.e., ANC < 100 μeq L -1), while <10% displayed much lower ANC (<50 μeq L -1). These methods may be readily adapted in other regions to assess stream water quality and potential biotic sensitivity to acidic inputs. ©2013. American Geophysical Union. All Rights Reserved.

Sullivan T.J.,E and S Environmental Chemistry Inc.
Water (Switzerland) | Year: 2012

Land management and natural resource public policy decision-making in the United States can benefit from two resource damage/recovery concepts: ecosystem service (ES) and critical load (CL). The purpose of this paper is to suggest an integrated approach to the application of ES and CL principles for public land management and natural resource policy decision-making. One well known example that is appropriate for ES and CL evaluation is examined here: the acidification of soil and drainage water by atmospheric deposition of acidifying sulfur and nitrogen compounds. A conceptual framework illustrates how the ES and CL approaches can be combined in a way that enhances the strengths of each. This framework will aid in the process of translating ES and CL principles into land management and natural resource policy decision-making by documenting the impacts of pollution on environmental goods and services that benefit humans. © 2012 by the authors.

Otten T.G.,Oregon State University | Crosswell J.R.,University of North Carolina at Chapel Hill | Mackey S.,E and S Environmental Chemistry Inc. | Dreher T.W.,Oregon State University
Harmful Algae | Year: 2015

Microcystis is a globally distributed cyanobacterium that forms dense surface scums in eutrophic freshwater bodies and is also capable of producing potent liver toxins (microcystins). Although it is not commonly observed in riverine environments, high concentrations of Microcystis cells - and microcystins - have been observed on a recurring basis in recent years throughout the Klamath River system (Oregon/California). In this study, a variety of genetic approaches were used to assess the connectivity of Microcystis populations found throughout the Klamath River. In 2012, samples were collected bi-weekly from 16 sites spanning the entire system, including all five reservoirs and Upper Klamath Lake. A newly designed QPCR assay targeting a conserved region within the c-phycocyanin β-subunit gene (. cpcB) was used along with a microcystin synthetase gene (. mcyE) targeting QPCR assay to quantify the spatiotemporal patterns of total and toxigenic Microcystis. These data were compared with traditional metrics, such as microscopic cell counts and analytical toxin measurements, and the public health implications are discussed. Overall, Microcystis was a minor constituent of the phytoplankton community above Copco and Iron Gate Reservoirs, although it was highly prolific within these reservoirs and our data indicate that most of these populations originate internally. Spatiotemporal variations in the proportional abundances of a single nucleotide polymorphism (SNP), identified by 454 deep sequencing of the cpcBA genes, was used to fingerprint Iron Gate Reservoir as the source of downriver Microcystis assemblages. Throughout the study period, the Microcystis populations remained highly toxic, with total microcystin concentrations ranging from 165. μg/L in Copco Reservoir to 3.6. μg/L within the lower estuary (0.8. km from the Pacific Ocean). These results demonstrate that large quantities of intact and toxic Microcystis cells can withstand passage through hydroelectric installations and transport over distances exceeding 300. km. This finding emphasizes that public health risk assessments should consider the impact of cyanobacterial blooms even when they originate in distant upstream locations within a watershed. © 2015.

Sullivan T.J.,E and S Environmental Chemistry Inc | Jenkins J.,Wildlife Conservation Society
Annals of the New York Academy of Sciences | Year: 2014

We discuss the potential for adopting a critical load (CL) of air pollutant-deposition approach to inform natural resource protection and management in New York. The CL reflects the quantitative exposure to pollutants below which significant harmful effects on specified sensitive elements of the environment do not occur. Here, we discuss how CLs can be used to protect sensitive ecosystems against the harmful effects of atmospheric sulfur and nitrogen deposition and associated soil and water acidification and nutrient enrichment. The CL can be used diagnostically to determine resources at risk and prescriptively to evaluate the effectiveness of regulations and to manage resources. © 2014 New York Academy of Sciences.

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