Titre du document / Document title

A regional analysis of lake acidification trends for the northeastern U.S., 1982-1994

Auteur(s) / Author(s)

STODDARD J. L. ⁽¹⁾ ; DRISCOLL C. T. ⁽²⁾ ; KAHL J. S. ⁽³⁾ ; KELLOGG J. H. ⁽⁴⁾ ;

Affiliation(s) du ou des auteurs / Author(s) Affiliation(s)

⁽¹⁾ Western Ecology Division, U.S. Environmental Protection Agency, 200 S. W. 35th Street, Corvallis, OR 97333, ETATS-UNIS
⁽²⁾ Dept. Civil & Environ. Engineering, Syracuse Univ., Syracuse, NY 13244, ETATS-UNIS
⁽³⁾ Water Resources Institute, Univ. Maine, Orono, ME 04469, ETATS-UNIS
⁽⁴⁾ Vermont DEC, Water Quality Division, 103 South Main Street, Waterburt, Vermont 05676, ETATS-UNIS

Résumé / Abstract

Acidic deposition is a regional phenomenon, but its effects have traditionally been studied using site- specific, intensive monitoring. We present trends information for 36 lakes of high-to-moderate acid sensitivity (defined as acid neutralizing capacity [ANC] < 100 μeq L^-1), and 15 deposition monitoring stations, in the northeastern U.S. for the period 1982-1994. Trends at each site were assessed through use of the Seasonal Kendall tau test; the resulting statistics were combined, through a technique analogous to analysis of variance, to produce quasi-regional estimates of change for key chemical variables. Rates of sulfate deposition declined significantly across all of the northeastern region during this time period, while rates of nitrate and ammonium deposition were unchanged. All lakes exhibited strong decreases in sulfate concentrations (ΔSO₄^2- = -1.7 μeq L^-1yr^-1, p<0.001) in response to declining sulfate deposition, but there was a strong contrast in the response of acid/base status between lakes in New England and lakes in the Adirondacks. As a group, the New England lakes exhibited recovery (ΔANC = +0.8 μeq L^-1yr^-1, p<0.001), while the Adirondack lakes exhibited either no trend or further acidification (as a group, ΔANC = -0.5 μeq L^-1yr^-1, p<0.01). This contrast can be attributed to changes in base cation concentrations: New England lakes exhibited base cations declines that were smaller in magnitude than declines in sulfate, producing the observed recovery in ANC; Adirondack lakes showed base cation declines that were very similar to those of sulfate, and no recovery was evident.

Revue / Journal Title

Environmental monitoring and assessment   ISSN 0167-6369   CODEN EMASDH 

Source / Source

Congrès
Symposium on the Environmental Monitoring and Assessment Program (EMAP) N^o3, Albany, NY , ETATS-UNIS (08/04/1997)
1998, vol. 51, n^o 1-2 (609 p.)  (1 p.1/4), pp. 399-413

Langue / Language

Anglais

Editeur / Publisher

Springer, Dordrect, PAYS-BAS  (1981) (Revue)

Mots-clés anglais / English Keywords

Metaanalysis ; Lakes ; Acidification ; Air pollution ; Freshwater environment ; United States ; North America ; America ;

Mots-clés français / French Keywords

Métaanalyse ; Lac ; Acidification ; Pollution air ; Nouvelle Angleterre ; Milieu eau douce ; Etats Unis ; Amérique du Nord ; Amérique ;

Mots-clés espagnols / Spanish Keywords

Mataanálisis ; Lago ; Acidificación ; Contaminación aire ; Medio agua dulce ; Estados Unidos ; America del norte ; America ;

Localisation / Location

INIST-CNRS, Cote INIST : 19359, 35400007538714.0310