Effects of urban land-use change on soil carbon pools and fluxes R. Pouyat, I. Yesilonis, P. Groffman, J. Russell-Anelli Funding: USDA FS Global Change Program, Center for Urban Environmental Research and Education (CUERE), Baltimore Ecosystem Study (BES)

LAND USE CHANGE EFFECTS ON SOIL ORGANIC CARBON ? NET EFFECTS?NET EFFECTS? RECOVERY?RECOVERY?

SMALL PARCELS DIVERSE LAND OWNERS INTENSIVE MANAGEMENT HIGHLY DISTURBED & COVERED SOILS URBAN CLIMATE CHANGE/POLLUTANTS REMNANT PATCHES URBAN SOIL MOSAIC

DISTURBED AND MADE SOILS

1. SOIL PHYSICAL DISTURBANCES MIXING AND COMPACTION MIXING AND COMPACTION DISRUPTION OF SOIL AGGREGATES DISRUPTION OF SOIL AGGREGATES DRAINAGE DRAINAGE 2. BURIAL AND COVERAGE OF SOIL LAND FILL LAND FILL IMPERVIOUS SURFACES IMPERVIOUS SURFACES REDUCED AERATION REDUCED AERATION 3. LOSS OF SURFACE HORIZONS (EROSION) SOIL DISTURBANCE EFFECTS?

Distance in Meters 1996 Profile 2002 Profile McGuire (2004) SUB SOIL DISTURBED SOIL TOP SOIL? 2600 m x 10 4 kg SOC ? BALTIMORE COUNTY

MADE SOIL ORGANIC C PEDON DATA REFUSE217.2 (±3.3) CLEAN FILL8 2.8 (±1.0) DREDGE (RECENT)124.7 DREDGE (OLD)4 3.8 (±0.3) C DENSITY (kg m -2 ) MADE SOIL TYPE n n = # of pits L. Hernandez, NRCS, NYC Soil Survey (NEW YORK CITY) D. Fanning, J.R. Short (WASHINGTON DC AND BALTIMORE)

r = 0.52 P < BALTIMORE CITY SOM (%) Bulk Density (Mg m -3 ) 0-5 cm n = land-use types Pouyat et al. 2001

MANAGEMENT/SITE HISTORY? SupplementsClipping ErosionCultivation

MARYLAND, USA TURFGRASS MAINTENANCE COSTS GOLF COURSES2,727 LAWN CARE FIRMS1,969 ATHLETIC FIELDS1,155 PARKS 450 DETACHED HOMES 369 CHURCHES 166 LAND-USE TYPE COST PER ACRE (IN U.S. DOLLARS) (MANAGEMENT EFFORT VARIES!)

Lawn Carbon Densities Residential grass Park use/grass Recreational use/grass Carbon Density (Kg/m 2 ) L. Hernandez, NRCS, NYC Soil Survey (NEW YORK CITY) H.K. Jo and E.G. McPhereson (CHICAGO) C.Y. Jim (HONG KONG) Stroganova et al. (MOSCOW) n = 2 n = 4 n = 6

From Qian and Follet (2002) Management /CoverManagement /Cover Site history

Golubiewski and Wessman, 2004, submitted Veg n=53 sites total (not all represented here) Soil n= 14 sites total Grass-land AGRIC. 1950s1960s1970s1980s 1990s Land Use or Decade of Development Carbon (kg m -2 ) Woody Vegetation C Lawn Stubble C SOC 0-10 cm SOC cm SOC cm AGE SINCE DEVELOPMENT Golubiewski and Wessman (2004, submitted)

P = 0.09 BALTIMORE COUNTY OMpH (n=11, lawns) 1980 (n=13, lawns) SOM g/100g Yesilonis, Pouyat, & Russell-Anelli 0-5 cm

1. Altered temperature regimes 2. Introduction of pollutants - Toxic and sub lethal effects - “Fertilization” (CO 2, N deposition) 3. Introduction of non-natives - Litter quality - Keystone species (earthworms) 4. Altered hydrologic processes URBAN ENVIRONMENTAL CHANGE

URBAN RURAL Soil Pb, Cu, Ni Soil Ca, Mg,Total salts Soil Temperature N, S, Ca, Mg deposition Exotic Earthworms/Mull FungiMicroinverts Mor soils Litter quality RESPONSE ALONG URBAN-RURAL GRADIENT IN NEW YORK CITY GRADIENT IN NEW YORK CITY Pouyat et al 1995

SOIL C POOLS (0-15 cm) PoolUrban Rural mg g -1 mg g -1 Readily Mineralizable 2.1 (0.5)7.4 (3.3) Labile (microbial) 6.9 (1.3)20.9 (2.6) Potentially Mineralizable 4.7 (0.5)6.8 (0.5) Passive (total) 97 (3.3)73 (4.3) Groffman et al. (1995)

SOIL ORGANIC C ?

p Data in Pouyat et al ? Remnant soils?

Mid-AtlanticSoutheastSouthwest Pre-AgriculturePre-Urban (Ag) Urban 11.56* x x x x x (?) x x x x kg C *soil organic carbon density to 1 m depth (kg C m -2 ); data for forest and crop SOC from Birdsey (1992) Net Change SOC in Hypothetical 1000 ha Urban Landscape Land-use and impervious cover data for 58 cities USA (Nowak et al., 1996)

1 m DEPTH SOIL CORES

BALTIMORE CITY Pouyat, Yesilonis and Russell-Anelli N n n = # plots (3 cores/plot)

BURIED A HORIZONS?

E. Ellis EcotopeMapping Historic Air Photos Change Analysis Stratify Samples

CONCLUSIONS 1.SOC pools vary widely in urban mosaic 2. Management & use affect SOC pools SOC pools: disturbances ↓, management ↑SOC pools: disturbances ↓, management ↑ Net effects depend on prevailing climateNet effects depend on prevailing climate 3. Urban environmental effects less important (pools/quality?), potentially more widespread 4. Permanence of urban land-use conversions has long-term implications (net gain or loss). 5. Uncertainties (spatial variation, C density measurements, covered soils, site history)