Atmospheric Deposition to Complex Terrain: Scaling

Up to the Landscape

K.C. Weathers, G.M. Lovett, S.E. Lindberg

S.M. Simkin, D.N. Lewis,

K. Schwarz Institute of Ecosystem Studies

Oak Ridge National Laboratory

Importance of QuantifyingAtmospheric Deposition• Ecologists

–Input/output budgets

–Biotic response

•Managers

–Protecting critical resources

• Policy makers

–Legislation

We Need Higher Resolution Data

Ecosystem

Inputs (nutrients, pollutants)

Outputs

PRIMENet Project Objectives

• Quantify total atmospheric deposition (S & N) to complex landscapes with a range of forest types and elevations

• Create and use deposition models to produce some of the first landscape scale maps of atmospheric deposition

• Identify HOTSPOTS of deposition

Methods• Record landscape features (ele, slo, asp,

veg) at sampling locations • Measure indices of deposition

a) Lead (Pb) in forest floor for GRSM

b) Sulfate (SO42-) in throughfall for ACAD

• Relate landscape features to deposition indices using General Linear Model

• Scaling-Up– apply GLM to each cell (pixel) of GIS database– convert deposition index to deposition value

using base values at NADP + CASTNet sites

Forest Floor Lead (Pb) as an

Index of Deposition

• Lead accumulates and remains in organic matter for decades

• Single sample yields a long-term index• Lead concentration calibrated against

traditional measures of deposition

β1 * Elevation

β2 * For Type

Deposition

+

=

Deposition = f(elevation, for type)

Preliminary

Preliminary

Throughfall Sulfate(SO4

2-) as an Index

of Deposition

• Collect throughfall on a monthly basis

• Concentrate anions of interest using ion exchange resin

Deposition = f(elevation, for type)

Preliminary

Preliminary

Conclusions

• Can identify areas likely to receive high nutrient and pollutant deposition load

• Surprisingly similar models for Smokies and Acadia

• Improved model of total atmospheric deposition improved data for ecosystem budgets, resource management, and policy formulation

Next Steps in Model

• Incorporate other landscape features – topographic exposure indices – distance to coast

• Use base deposition data to produce maps with deposition values for ACAD and GRSM parks

• Additional work funded by NPS at ACAD – link with UMO surface water chemistry – compare with watershed scale deposition

We are indebted to all the people at Acadia and Great Smoky Mountains National Parks that

have made this project successful and enjoyable

Distance to coast (m)

Distance to coast (m)

Relative Deposition Index

Low

High

Deposition = f(veg type,elevation)