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Piña AJ, Schumacher RS, Denning AS, Faulkner WB, Baron JS, Ham J, Ojima DS, Collett JL. Reducing Wet Ammonium Deposition in Rocky Mountain National Park: the Development and Evaluation of A Pilot Early Warning System for Agricultural Operations in Eastern Colorado. Environ Manage 2019; 64:626-639. [PMID: 31583444 DOI: 10.1007/s00267-019-01209-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 09/05/2019] [Indexed: 06/10/2023]
Abstract
Agricultural emissions are the primary source of ammonia (NH3) deposition in Rocky Mountain National Park (RMNP), a Class I area, that is granted special air quality protections under the Clean Air Act. Between 2014 and 2016, the pilot phase of the Colorado agricultural nitrogen early warning system (CANEWS) was developed for agricultural producers to voluntarily and temporarily minimize emissions of NH3 during periods of upslope winds. The CANEWS was created using trajectory analyses driven by outputs from an ensemble of numerical weather forecasts together with the climatological expertize of human forecasters. Here, we discuss the methods for the CANEWS and offer preliminary analyses of 33 months of the CANEWS based on atmospheric deposition data from two sites in RMNP as well as responses from agricultural producers after warnings were issued. Results showed that the CANEWS accurately predicted 6 of 9 high N deposition weeks at a lower-elevation observation site, but only 4 of 11 high N deposition weeks at a higher-elevation site. Sixty agricultural producers from 39 of Colorado's agricultural operations volunteered for the CANEWS, and a two-way line of communication between agricultural producers and scientists was formed. For each warning issued, an average of 23 producers responded to a postwarning survey. Over 75% of responding CANEWS participants altered their practices after an alert. While the current effort was insufficient to reduce atmospheric deposition, we were encouraged by the collaborative spirit between agricultural, scientific, and resource management communities. Solving a broad and complex social-ecological problem requires both a technological approach, such as the CANEWS, and collaboration and trust from all participants, including agricultural producers, land managers, university researchers, and environmental agencies.
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Affiliation(s)
- Aaron J Piña
- Earth Science Division, NASA Headquarters, Washington, DC, USA.
| | - Russ S Schumacher
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
| | - A Scott Denning
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
| | - William B Faulkner
- Department of Biological and Agricultural Engineering, Texas A&M University, College Station, TX, USA
| | - Jill S Baron
- US Geological Survey, Fort Collins Science Center, Fort Collins, CO, USA
| | - Jay Ham
- Department of Soil & Crop Sciences, Colorado State University, Fort Collins, CO, USA
| | - Dennis S Ojima
- Department of Ecosystem Science and Sustainability, Colorado State University, Fort Collins, CO, USA
| | - Jeffrey L Collett
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, USA
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Benedict KB, Prenni AJ, Sullivan AP, Evanoski-Cole AR, Fischer EV, Callahan S, Sive BC, Zhou Y, Schichtel BA, Collett Jr JL. Impact of Front Range sources on reactive nitrogen concentrations and deposition in Rocky Mountain National Park. PeerJ 2018; 6:e4759. [PMID: 29780668 PMCID: PMC5958887 DOI: 10.7717/peerj.4759] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Accepted: 04/23/2018] [Indexed: 11/20/2022] Open
Abstract
Human influenced atmospheric reactive nitrogen (RN) is impacting ecosystems in Rocky Mountain National Park (ROMO). Due to ROMO's protected status as a Class 1 area, these changes are concerning, and improving our understanding of the contributions of different types of RN and their sources is important for reducing impacts in ROMO. In July-August 2014 the most comprehensive measurements (to date) of RN were made in ROMO during the Front Range Air Pollution and Photochemistry Éxperiment (FRAPPÉ). Measurements included peroxyacetyl nitrate (PAN), C1-C5 alkyl nitrates, and high-time resolution NOx, NOy, and ammonia. A limited set of measurements was extended through October. Co-located measurements of a suite of volatile organic compounds provide information on source types impacting ROMO. Specifically, we use ethane as a tracer of oil and gas operations and tetrachloroethylene (C2Cl4) as an urban tracer to investigate their relationship with RN species and transport patterns. Results of this analysis suggest elevated RN concentrations are associated with emissions from oil and gas operations, which are frequently co-located with agricultural production and livestock feeding areas in the region, and from urban areas. There also are periods where RN at ROMO is impacted by long-range transport. We present an atmospheric RN budget and a nitrogen deposition budget with dry and wet components. Total deposition for the period (7/1-9/30) was estimated at 1.58 kg N/ha, with 87% from wet deposition during this period of above average precipitation. Ammonium wet deposition was the dominant contributor to total nitrogen deposition followed by nitrate wet deposition and total dry deposition. Ammonia was estimated to be the largest contributor to dry deposition followed by nitric acid and PAN (other species included alkyl nitrates, ammonium and nitrate). All three species are challenging to measure routinely, especially at high time resolution.
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Affiliation(s)
- Katherine B. Benedict
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, United States of America
| | - Anthony J. Prenni
- Air Resources Division, National Park Service, Lakewood, CO, United States of America
| | - Amy P. Sullivan
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, United States of America
| | - Ashley R. Evanoski-Cole
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, United States of America
- Present address: Department of Chemistry, St. Bonaventure University, St. Bonaventure, NY, United States of America
| | - Emily V. Fischer
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, United States of America
| | - Sara Callahan
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, United States of America
| | - Barkley C. Sive
- Air Resources Division, National Park Service, Lakewood, CO, United States of America
| | - Yong Zhou
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, United States of America
| | - Bret A. Schichtel
- Air Resources Division, National Park Service, Fort Collins, CO, United States of America
| | - Jeffrey L. Collett Jr
- Department of Atmospheric Science, Colorado State University, Fort Collins, CO, United States of America
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Dunnette PV, Higuera PE, McLauchlan KK, Derr KM, Briles CE, Keefe MH. Biogeochemical impacts of wildfires over four millennia in a Rocky Mountain subalpine watershed. New Phytol 2014; 203:900-912. [PMID: 24803372 DOI: 10.1111/nph.12828] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Accepted: 03/31/2014] [Indexed: 06/03/2023]
Abstract
Wildfires can significantly alter forest carbon (C) storage and nitrogen (N) availability, but the long-term biogeochemical legacy of wildfires is poorly understood. We obtained a lake-sediment record of fire and biogeochemistry from a subalpine forest in Colorado, USA, to examine the nature, magnitude, and duration of decadal-scale, fire-induced ecosystem change over the past c. 4250 yr. The high-resolution record contained 34 fires, including 13 high-severity events within the watershed. High-severity fires were followed by increased sedimentary N stable isotope ratios (δ15N) and bulk density, and decreased C and N concentrations--reflecting forest floor destruction, terrestrial C and N losses, and erosion. Sustained low sediment C : N c. 20-50 yr post-fire indicates reduced terrestrial organic matter subsidies to the lake. Low sedimentary δ15N c. 50-70 yr post-fire, coincident with C and N recovery, suggests diminishing terrestrial N availability during stand development. The magnitude of post-fire changes generally scaled directly with inferred fire severity. Our results support modern studies of forest successional C and N accumulation and indicate pronounced, long-lasting biogeochemical impacts of wildfires in subalpine forests. However, even repeated high-severity fires over millennia probably did not deplete C or N stocks, because centuries between high-severity fires allowed for sufficient biomass recovery.
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Affiliation(s)
- Paul V Dunnette
- College of Natural Resources, University of Idaho, PO Box 441133, Moscow, ID, 83844-1133, USA
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