1
|
McDonnell TC, Driscoll CT, Sullivan TJ, Burns DA, Baldigo BP, Shao S, Lawrence GB. Regional target loads of atmospheric nitrogen and sulfur deposition for the protection of stream and watershed soil resources of the Adirondack Mountains, USA. Environ Pollut 2021; 281:117110. [PMID: 33872891 DOI: 10.1016/j.envpol.2021.117110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 01/07/2021] [Revised: 04/01/2021] [Accepted: 04/06/2021] [Indexed: 06/12/2023]
Abstract
Acidic deposition contributes to a range of environmental impacts across forested landscapes, including acidification of soil and drainage water, toxic aluminum mobilization, depletion of available soil nutrient cations, and impacts to forest and aquatic species health and biodiversity. In response to decreasing levels of acidic deposition, soils and drainage waters in some regions of North America have become gradually less acidic. Thresholds of atmospheric deposition at which adverse ecological effects are manifested are called critical loads (CLs) and/or target loads (TLs). Target loads are developed based on approaches that account for spatial and temporal aspects of acidification and recovery. Exceedance represents the extent to which current or projected future levels of acidic deposition exceed the level expected to cause ecological harm. We report TLs of sulfur (S) and nitrogen (N) deposition and the potential for ecosystem recovery of watershed soils and streams in the Adirondack region of New York State, resources that have been less thoroughly investigated than lakes. Regional TLs were calculated by statistical extrapolation of hindcast and forecast simulations of 25 watersheds using the process-based model PnET-BGC coupled with empirical observations of stream hydrology and established sensitivity of sugar maple (Acer saccharum) to soil base saturation and brook trout (Salvelinus fontinalis) to stream acid neutralizing capacity (ANC). Historical impacts and the expected recovery timeline of regional soil and stream chemistry and fish community condition within the Adirondack Park were evaluated. Analysis suggests that many low-order Adirondack streams and associated watershed soils have low TLs (<40 meq/m2/yr of N + S deposition) to achieve specified benchmarks for recovery of soil base saturation or stream ANC. Acid-sensitive headwater and low-order streams and watershed soils in the region are expected to experience continued adverse effects from N and S deposition well into the future even under aggressive emissions reductions. Watershed soils and streams in the western Adirondack Park are particularly vulnerable to acidic deposition and currently in exceedance of TLs. The methods used for linking statistical and process-based models to consider chemical and biological response under varying flow conditions at the regional scale in this study can be applied to other areas of concern.
Collapse
Affiliation(s)
- T C McDonnell
- E&S Environmental Chemistry, Inc., PO Box 609, Corvallis, OR, 97339, USA.
| | - C T Driscoll
- Department of Civil and Environmental Engineering, Syracuse University, 151 Link Hall, Syracuse, NY, 13244, USA
| | - T J Sullivan
- E&S Environmental Chemistry, Inc., PO Box 609, Corvallis, OR, 97339, USA
| | - D A Burns
- U.S. Geological Survey New York Water Science Center, 425 Jordan Road, Troy, NY, 12180, USA
| | - B P Baldigo
- U.S. Geological Survey New York Water Science Center, 425 Jordan Road, Troy, NY, 12180, USA
| | - S Shao
- Department of Civil and Environmental Engineering, Syracuse University, 151 Link Hall, Syracuse, NY, 13244, USA
| | - G B Lawrence
- U.S. Geological Survey New York Water Science Center, 425 Jordan Road, Troy, NY, 12180, USA
| |
Collapse
|