Purpose and Study Design
6
TABLE 1.1 RECOMMENDED AQRVs, SENSITIVE RECEPTORS, AND
INDICATORS AFFECTED BY ATMOSPHERIC DEPOSITION OF AIR
POLLUTANTS
AQRV
Sensitive Receptor
Indicator/Metric
Potential Criteria a
Flora
Red spruce (East)
Growth
Decline
Change in diameter
Change in extent of
damage
Sugar maple (East)
Growth
Decline
Change in diameter
Change in extent of
damage
Lichens
Community composition
Loss of sensitive
taxa
Soil
Soil chemistry
Base saturation (BS)
Exchangeable Ca 2+
Exchangeable Ca 2+ + Mg 2+
C:N molar ratio
BS < 10%
% change over time
% change over time
C:N < 0.2
Soil solution
chemistry
Ca:Al molar ratio
[Ca 2+ + Mg 2+ + K + ]:Al molar
ratio
NO 3
− concentration
Ca:Al < 1.0
BC:Al < 1.0
NO 3
− > 20 μeq/L
during growing
season
Water
Water chemistry
ANC
NO 3
− concentration
SO 4
2− concentration
ANC < 50 μeq/L
NO 3 > 10 μeq/L
Change over time
Water productivity
Chlorophyll a
Clarity (lakes)
Change over time
Change over time
Fish
Salmonid species
presence
Fish species richness
Fish condition factor
Fish Hg concentration
Fish pesticides
concentration
Loss over time
Change over time
Change over time
Hg > 0.3 ppm
Above threshold
values
Zooplankton (lakes)
Total zooplankton
richness
Crustacean taxonomic
richness
Rotifer taxonomic
richness
Change over time
Change over time
Change over time