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Jonah Natural Gas Field

1986 2008

Using Lichens to Monitor Nitrogen Deposition Near Natural Gas Drilling in the Wind

River Range, WY Jill A. McMurray1, Dave W. Roberts2, Mark E. Fenn1, Linda H. Geiser1, Sarah Jovan1

US Forest Service1

Montana State University2

• Rapid expansion of natural gas drilling in the last decade has

raised concerns about the potential ecological effects of

nitrogen deposition to the western Wind River Range (WRR),

WY. We asked the following questions:

• What is the quantity (kg ha-1year-1) of reduced, oxidized, and

total dissolved inorganic nitrogen (DIN) depositing in the

Wind River Range (WRR)?

• What is the spatial distribution of N deposition in the WRR?

• Can N concentrations from Letharia vulpina and Usnea

lapponica be calibrated against annual N throughfall (TF)

deposition (kg ha-1year-1) to provide an economical means to

maximize future monitoring?

• In the summer of 2010, nine temporary 0.378 hectare

circular plots were established in the WRR just outside the

Bridger Wilderness (FIA P3 Field Guide 2011). At each plot,

nine passive ion exchange resin-filled collectors (IER) were

installed to measure throughfall (TF) deposition (Fenn and

Poth 2004). In addition, lichen thalli from Letharia vulpina

and Usnea lapponica were collected for elemental analysis

(Geiser 2004).

• Two to three plots were installed in four different drainages

on the west side of the WRR in either mature Pseudotsuga

menziesii or Picea engelmannii dominated forests.

• After one year IER tubes were removed and two to four

samples (at least 10 grams) of lichen thalli were collected

from each plot for analysis.

• N concentrations in lichen thalli can be used to estimate N

deposition in the Wind River Range.

• N deposition in the Boulder drainage is elevated (>4.0 kg ha-

1year-1) with clear empirical evidence of damaged lichen

thalli.

• All other drainages are near background conditions which

suggests a local and not a long-distance source of N

pollution.

• Monitoring should continue in the WRR to track changes in

and increase spatial resolution of N deposition.

• DIN deposition ranged from 0.78 – 4.13. The three highest

DIN measurements were from the Boulder Drainage (Fig 1).

• N concentrations in U. lapponica and L.vulpina ranged from

1.19 – 2.42 and 0.97- 1.56 respectively. Lichen thalli % N

was highest in plots closest to oil and gas fields (Fig. 2).

• Linear relationships existed between TF N and % N in

lichen thalli (Fig 3-5).

• Lichen samples were cleaned of debris (Geiser 2004) and

sent to the University of Minnesota Research Analytical

Laboratory for total ash and N analyses. Ions were extracted

from IER tubes with 1 M KI (Fenn and Poth 2004) using an

analysis procedure modified from Simkin et al (2004)

• Within and between plot variation for both lichen N

concentrations and IER TF measurements were evaluated

with the coefficient of variation and standard error.

• Simple linear regression was used to approximate the

relationships between lichen N concentrations and TF

deposition kg ha-1 year-1 for NO3-–N, NH4

+–N and DIN (R

Development Core Team 2011).

Study Need and Questions Asked

Methods

Analysis

Results

Conclusions

Study Area

Fenn, M.E, & Poth, M.A. (2004). Monitoring nitrogen deposition in throughfall using ion exchange resin

columns: a field test in the San Bernardino Mountains. J. Environ. Qual., 33(6), 2007-2014.

Forest Inventory and Analysis Phase 3 Field Guide, version 5.1. (2011). http://www.fia.fs.fed.us/library/field-

guides-methods-proc/docs/2012/field_guide_p3_5-1_sec21_10_2011.pdf

Geiser, L. (2004). Manual for Monitoring Air Quality Using Lichens on National Forests of the Pacific

Northwest. USDA-Forest Service Pacific Northwest Region Technical Paper, R6-NR-AQ-TP-1-04. 126 p.

R Development Core Team (2011). R: A language and environment for statistical computing. R Foundation for

Statistical Computing, Vienna, Austria. ISBN 3-900051-07-0, URL http://www.R-project.org/.

Simkin, S.M., Lewis, D.N., Weathers, K.C., Lovett, G.M., and Schwarz, K. (2004). Determination of sulfate,

nitrate, and chloride in throughfall using ion-exchange resins. Water, Air, and Soil Pollut. 153, 343-354.

Sverdrup, H., McDonnell, T.C., Sullivan, T.J., Nihlgård, B., Belyazid, S., Rihm, B. (2012). Testing the feasibility

of using the ForSAFE-VEG model to map the critical load of nitrogen to protect plant biodiversity in the Rocky

Mountains Region, USA. Water, Air, and Soil Pollution, 223(1), 371-387.

References

Figures

Lichens

Letharia vulpina & Usnea lapponica

BLO BMD BUP PCM PCF GRM GRG BSH BSD

DIN

Ammonium_N

Nitrate_N

Throughfall deposition

kg

/ha

/yr

01

23

45

Boulder Pine Creek Green River Big Sandy

Fig 1. Annual TF N deposition from four drainages in the Wind

River Range. DIN refers to total dissolved inorganic N

(ammonium N plus nitrate N). The red line represents

background levels of N deposition in the Northern Rockies as

estimated by Sverdrup et al. (2012).

1.2 1.4 1.6 1.8 2.0 2.2 2.4

1.0

1.5

2.0

2.5

3.0

3.5

4.0

% N Usnea lapponica

Th

rou

gh

fall D

IN (

kg

/ha

/yr)

TF N = 3.05(%N) - 3.12

adj R^2 = 0.91

p = >0.001

DIN

1.2 1.4 1.6 1.8 2.0 2.2 2.4

0.5

1.0

1.5

2.0

2.5

% N Usnea lapponica

Th

rou

gh

fall N

fro

m N

H4

(kg

/ha

/yr)

TF N = 1.73(%N) - 1.70

adj R^2 = 0.92

p = 3.07e-05

Ammonium

1.2 1.4 1.6 1.8 2.0 2.2 2.4

0.5

1.0

1.5

% N Usnea lapponica

Th

rou

gh

fall N

fro

m N

O3

(kg

/ha

/yr)

TF N = 1.31(%N) - 1.39

adj R^2 = 0.75

p = 0.0015

Nitrate

Throughfall IER monitors

Table 1 Coefficient of variation (CV) for within and between plot measurements of

lichen thalli. Usnea = U. lapponica and Letharia = L. vulpina.

Within plot CV

±

Between plot CV

±

Between vs. Within

Usnea N 0.03 0.23 6.93

Letharia N 0.04 0.15 3.98

TF total N 0.32 0.78 2.42

TF NH4+–N 0.39 0.80 2.06

TF NO3-–N 0.52 0.92 1.76

Table 2 Measures of throughfall N deposition (kg N ha-1

year-1

) and lichen N

concentrations (% dry weight) in the Wind River Range. Elev = elevation, Dist. =

distance to the middle of the PA gas field, DIN = dissolved inorganic nitrogen. SE =

standard error. Usn. = U. lapponica and Let. = L. vulpina.

Plot Drainage Elev.

(m)

Dist.

(km)

DIN SE

DIN

% N

Usn.

% N

Let. BLO Boulder 2248 24.5 4.13 0.47 2.42 -- BMD Boulder 2241 25.5 3.24 0.34 1.90 1.56 BUP Boulder 2256 26.0 1.81 0.18 1.62 1.34 PCM Pine Creek 2713 39.5 1.21 0.11 1.54 -- GRM Green River 2661 78.5 1.01 0.13 1.19 -- BSH Big Sandy 2800 41.5 0.97 0.10 1.39 -- GRG Green River 2409 68.0 0.91 0.10 1.29 1.12 PCF Pine Creek 2288 42.5 0.90 0.13 1.40 1.24 BSD Big Sandy 2706 42.5 0.78 0.07 1.38 0.97

Table 3 Regression models and approximated equations. * = Note, since linear

regressions are not inverse relationships (due to differences in horizontal and vertical

errors) one equation could not be used to solve for both lichen species.

Model Regression equation R2 n p-value

TF DIN (y) vs. U. lapponica % N (x) y = 3.05x – 3.12 0.91 9 <0.001

TF NH4+–N (y) vs. U. lapponica % N (x) y = 1.73x – 1.70 0.92 9 <0.001

TF NO3-–N (y) vs. U. lapponica % N (x) y = 1.31x – 1.39 0.75 9 <0.01

TF DIN (y) vs. L. vulpina % N (x) y = 4.26x – 3.77 0.78 5 <0.05

TF NH4+–N (y) vs. L. vulpina % N (x) y = 1.70x – 1.19 0.57 5 0.087

TF NO3-–N

(y) vs. L. vulpina % N (x) y = 2.56x – 2.59 0.84 5 <0.05

L. vulpina% N (y) vs U. lapponica % N (x) y = 0.99x – 0.29 0.83 12 <0.001

U. lapponica % N (y) vs L. vulpina% N (x)* y = 0.84x + 0.48 0.83 12 <0.001

Green River, Pine Creek, Boulder, Big Sandy represent

the three drainages in which this study took place.

Fig. 2. Log Transformation for N concentrations in U.

lapponica vs distance from the center of the Pinedale Anticline

natural project area. curve = 7.54 – 3.38x +0.39x2. r2 = 0.76, p =

0.006. The points in the center of the graph are not co-located.

Fig. 3-5. Simple linear regression of %N in lichen vs. throughfall (TF) dissolved inorganic N, NO3—N, and NH4

+-N deposition (kgha-1year-1).

Dotted lines represent 95% confidence bands.

3.2 3.4 3.6 3.8 4.0 4.2 4.4

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

log (distance km)lo

g(N

co

nc. U

. la

pp

on

ica

)

BLO

BMD

BUP

GRG

GRM