Skip to page content
USDA Forest Service
  
Treesearch

Research & Development Treesearch

 
Treesearch Home
About Treesearch
Contact Us
Research & Development
Forest Products Lab
International Institute of Tropical Forestry
Northern
Pacific Northwest
Pacific Southwest
Rocky Mountain
Southern Research Station
Help
 

Science.gov - We Participate


USA.gov  Government Made Easy


Global Forest Information Service

US Forest Service
P.O. Box 96090
Washington, D.C.
20090-6090

(202) 205-8333

You are here: Home / Search / Publication Information
Bookmark and Share

Publication Information

View PDF (428 KB)

Title: Critical Loads of Acid Deposition for Wilderness Lakes in the Sierra Nevada (California) Estimated by the Steady-State Water Chemistry Model

Author: Shaw, Glenn D.; Cisneros, Ricardo; Schweizer, Donald; Sickman, James O.; Fenn, Mark E.;

Date: 2014

Source: Water, Air, & Soil Pollution. 225(1)

Publication Series: Scientific Journal (JRNL)

Description: Major ion chemistry (2000-2009) from 208 lakes (342 sample dates and 600 samples) in class I and II wilderness areas of the Sierra Nevada was used in the Steady-State Water Chemistry (SSWC) model to estimate critical loads for acid deposition and investigate the current vulnerability of high elevation lakes to acid deposition. The majority of the lakes were dilute (mean specific conductance = 8.0 µS cm−1) and characterized by low acid neutralizing capacity (ANC; mean = 56.8µeq L−1). Two variants of the SSWC model were employed: (1) one model used the F-factor and (2) the alternate model used empirical estimates of atmospheric deposition and mineral weathering rates. A comparison between the results from both model variants resulted in a nearly 1:1 slope and an R2 value of 0.98, suggesting that the deposition and mineral weathering rates used were appropriate. Using an ANClimit of 10 µeq L−1, both models predicted a median critical load value of 149 eq ha−1 year−1 of H+ for granitic catchments. Median exceedances for the empirical approach and F-factor approach were −81 and −77 eq ha−1 year−1, respectively. Based on the F-factor and empirical models, 36 (17 %) and 34 (16 %) lakes exceeded their critical loads for acid deposition. Our analyses suggest that high elevation lakes in the Sierra Nevada have not fully recovered from the effects of acid deposition despite substantial improvement in air quality since the 1970s.

Keywords: Lake Acidification, Sierra Nevada, Critical Loads, Nitrogen deposition, Class I Wilderness areas, Lake monitoring

Publication Notes:

  • We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
  • This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.

XML: View XML

Citation:


Shaw, Glenn D.; Cisneros, Ricardo; Schweizer, Donald; Sickman, James O.; Fenn, Mark E. 2014. Critical loads of acid deposition for wilderness lakes in the Sierra Nevada (California) estimated by the Steady-State Water Chemistry Model. Water, Air, & Soil Pollution. 225(1).

 


 [ Get Acrobat ]  Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility

USDA logo which links to the department's national site. Forest Service logo which links to the agency's national site.