A comparison of soil characteristics of an ultra-

and a sub-urban area

Ian YesilonisRichard Pouyat

Citywide results

• P, K, and bulk density differentiated forest from residential soils possibly due to management.

• Ca and pH differentiated residential grass from other turf grass cover types.

• Cu, Pb, and Zn were related to automobile sources and not related to TRI sites.

• Heavy metals were not explained by land use/cover at citywide scale.

Neighborhood scale• Ultra urban inner city neighborhood (WS263)• Suburban neighborhood (Cub Hill)

Methods

• The 0-5 cm soil samples were taken randomly stratified by an Ecotope land use/cover classification system.

• The soils were digested with a strong acid.

High residential density watershed

Low residential density watershed

1 km radius

Sampling design

• Mostly constructed

Watershed 263 Ecotope map

ResultsC: ConstructedD: DisturbedOM: Ornamental

Mixed vegetationOP: Ornamental Perennial

WS 263 is higher in most soil metal and nutrient concentrations for each Ecotope class.

Automobile by-products

Pb: 22, 120, 1700, 11, 56State average, Eco-SSL:plants, soil invertebrates, avian, and mammalian wildlife Cu: 20, 70, 80, 28, 51

Zn: 39

Coal by-products

V: 63, (m) 280 Cr: 47.9, (m) Cr III 34, Cr IV 81

Urban deposition of Calcium?

Lawn nutrients

Is the potassium from the surface geology, ie. Plagioclase feldspars?

pH series

Increased management of young lawns?

Opposite of what we expected!

Conclusions• WS 263 had greater concentrations of Ca,

Zn, Pb, S, Cu, As, and Mn than Cub Hill.– The only metal of concern in WS 263 Pb.

• Cub Hill had greater concentrations of K.

• For the residential soils of Cub Hill Ca and pH were weakly correlated to age of residential development.

Future Research

• Identify hot spots for accumulation of metals– Community awareness (intervention) – Directing mitigation efforts

• Understand relationship of metals to human exposure– Transport and movement– Source sink relationships

Acknowledgements

• Thanks to the Cub Hill and WS263 residents who allowed us to take soil samples

• Ben Smith, Abe Kloze, Kate Donovan, and Laura Norris.

• Dave Nowak and Jeff Walton.

• Funding and in-kind support– USFS, BES, CUERE

Cub Hill land use conversion from 1938 to 1996

1938

1943

1953

1996