Biomonitoring with Lichens in Southern Californiacalnat.ucanr.edu/files/249994.pdf · 2016. 10....
Transcript of Biomonitoring with Lichens in Southern Californiacalnat.ucanr.edu/files/249994.pdf · 2016. 10....
Using lichens to monitor
nitrogen pollution in Southern
California
Jennifer Riddell
AAAS Science and Technology Policy Fellow, US EPA
Tom Nash- Arizona State University
Sarah Jovan, Pamela Padgett, USDA Forest Service
Figure courtesy of NASA GSFC program: http://ltpwww.gsfc.nasa.gov/globe/NFTG/nitrocyc.htm
The Nitrogen Cycle
Important N deposition factors to consider
• Toxicity in the ecosystem
• Critical loads
National Trend Network (NTN) monitoring sites
1985
Nitrate Ion Concentrations
1985-2008
Maps from National Atmospheric Deposition Program
http://nadp.sws.uiuc.edu/data/animaps.aspx
1986
Nitrate Ion Concentrations
1985-2008
1987
Nitrate Ion Concentrations
1985-2008
1988
Nitrate Ion Concentrations
1985-2008
1989
Nitrate Ion Concentrations
1985-2008
1990
Nitrate Ion Concentrations
1985-2008
1991
Nitrate Ion Concentrations
1985-2008
1992
Nitrate Ion Concentrations
1985-2008
1993
Nitrate Ion Concentrations
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1994
Nitrate Ion Concentrations
1985-2008
1995
Nitrate Ion Concentrations
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1996
Nitrate Ion Concentrations
1985-2008
1997
Nitrate Ion Concentrations
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1998
Nitrate Ion Concentrations
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1999
Nitrate Ion Concentrations
1985-2008
2000
Nitrate Ion Concentrations
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2001
Nitrate Ion Concentrations
1985-2008
2002
Nitrate Ion Concentrations
1985-2008
2003
Nitrate Ion Concentrations
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2004
Nitrate Ion Concentrations
1985-2008
2005
Nitrate Ion Concentrations
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Nitrate Ion Concentrations
1985-2008
2006
Nitrate Ion Concentrations
1985-2008
2007
Nitrate Ion Concentrations
1985-2008
2008
Drawbacks: NTN sites in Southern
California
History of study area: Air quality
Data source: CA Air Resource Board 2013 Almanac
0
20
40
60
80
100
120
140
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200
Da
ys
> S
tan
da
rd
San Bernardino 4th St Monitor: Days exceeding ozone standards
State 1-hr Standard
State 8-hr Standard
National 1-hr Standard
National 8-hr Standard
Poly. (State 8-hr Standard)
0
50000
100000
150000
200000
250000
300000
350000
400000
450000
500000
Population/100
Avg. Daily VMT/1000
South Coast Air Basin
Percent Growth in Population and Vehicle Miles Traveled
CARB 2013 Almanac figure 4-2
381,013,000 VMT per day!
17,800,000 people in SCAB counties
Barton Flat
Crestline
Study Area
Estimated Historic Total N Deposition (data from Fenn et al . 2008)
0
10
20
30
40
50
60
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1930 1940 1950 1960 1970 1980 1990 2000 2005
kg
ha
-1 y
r-1
Camp Paivika
Barton Flat
Crestline
History of study area: Air quality
Critical load for
elevated stream
water [NO3- ]
(~17 kg/ha/year)
(Fenn and Poth 1999)
Critical load for
elevated Letharia
vulpina tissue % N
(~3 kg/ha/year)
(Fenn et al. 2008)
So Why Lichens?
• Lichens extract nutrients and moisture
almost entirely from the air.
• Consolidate airborne elements, and
respond quickly to shifting air quality.
Clean Polluted
Sites Sites
Community composition
changes in relation to
air quality
Nitrophytic lichen
cover at Camp
Paivika (near
Crestline)
~ 71 kg/ha/year
N deposition
Morphological changes in pollution tolerant species
Hypogymnia imshaugii
at a clean site
H. imshaugii
At polluted sites
Twofold Study Objectives
Compare community
composition changes
over 30 years
Create and test model using lichen
communities to predict air quality,
particularly N deposition
• Hasse-1913 • Lichen flora of Southern California
• Sigal (1979) • ~ 50% montane spp. extirpated
• Spp. loss correlated with O3 gradient
History of study area:
Lichen studies
Methods19 Sigal sites revisited – 22 total sites
• Lichen % cover transects
– Considerations:
• Secondary stand
attributes
• Substrate pH
• Twig NO3-
Study Area
0.00
5.00
10.00
15.00
20.00
25.00
30.00
35.00
1976 2008 1976 2008 1976 2008
Angeles National Forest Mt Palomar / Cleveland N.F. San Bernardino N.F.
Parmelia subolivacea
Physcia tenella
Physia grisea
Xanthoria fallax
~ Moderately tolerant
~Nitrophyte (tolerant)
~Nitrophyte (tolerant)
~Nitrophyte (tolerant)
Changes in % cover 1977-2008
Physconia spp.
Model: PCORD community ordinations
generated lichen species community “air scores” by comparing site % cover
Added 32 environmental parameters in model:
• CMAQ modeled N deposition NHx, Ox. N
• Through fall total N deposition (collected in resin tubes
under the canopy)
• Passive monitor NH3, HNO3, NO2, and O3
• Twig N
Predicting N Deposition
Using Lichens
Ordination axes for 2008 lichen cover
on oaks
85.6% of community variation
explained by model, with
49.7% of variation explained
by N related axes
NMS index Eutroph
index
r2 r2
Deposition measurements Throughfall N 0.94 0.77
Twig NO3- 0.58 0.42
Deposition estimates
Total Dry N 0.62 0.34
Dry NOx 0.60 0.35
Total N (wet + dry) 0.49 0.22
Dry NHx 0.48 0.24
Dry atm. NH4+ 0.38 0.27
Dry atm. NO3- 0.36 0.21
All atm. N 0.06 0.00
Wet NHx 0.05 0.00
Wet atm. NH4+ 0.05 0.00
Total Wet N 0.03 0.01
Wet NOx 0.01 0.03
Wet atm. NO3- 0.01 0.02
Gas concentration
measurements
HNO3 average 0.59 0.27
Total N average 0.50 0.23
O3 maximum 0.49 0.43
NH3 average 0.47 0.27
NO2 average 0.42 0.19
Site environmental
variables
Temp. 0.49 0.63
Dew point 0.49 0.53
Elevation 0.48 0.40
pH of oak bole 0.43 0.24
pH of twigs 0.01 0.00
Precipitation 0.00 0.021
Key findings:
Pearson’s correlations
significance p < 0.05 bolded
(1) indices correlated
similarly but NMS
stronger
(2) eutrophs closely tied
to throughfall dep.
(3) next best: dry and
oxidized N dep.
(4) HNO3 correlation is
comparably good; best
gas predictor for NMS
index
(5) NH3/reduced N vars
are comparatively weak
Thrufall N measurements / Twig
N correlation
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0 10 20 30 40 50 60 70 80
Twig Nitrate vs. Thrufall
Through fall N (kg/ha/year)
Tw
ig s
urf
ace
NO
3-(μg
cm
2)
r2 = 0.87
CMAQ Modeled Dry Oxidized N Twig Nitrate
Lichen Community Air Scores
Community
Air Score
CMAQ Dry Ox. N r2 = 0.78
Twig surface
NO3- r2 = 0.76
Throughfall N r2 = 0.94
Conclusions• Nitrogen = important driver of lichen community
composition in S. California (communities shifted from neutrophytes to nitrophytes)
• Twig nitrate was a useful tool to estimate relative N deposition
• Nitrogen pollution seems to have an increasing influence on lichen communities in S. CA over the last 30 years.
Thanks ToLorene Sigal ~ for providing inspiration and
data from 1977
Tom Nash, Pam Padgett and Sarah Jovan
~for constant intellectual and fiscal support
David Jones ~ for running untold numbers
of samples on the Dionex
Funding Sources
USDA Forest Service Pacific Southwest
Research Station
USDA FIA P3 Program
US EPA STAR Fellowship Program
Arizona State University