Effects of urban land-use change on soil carbon pools and fluxes

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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)
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LAND USE CHANGE EFFECTS ON SOIL ORGANIC CARBON
?

• NET EFFECTS?
• RECOVERY?

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URBAN SOIL MOSAIC
SMALL PARCELS DIVERSE LAND OWNERS INTENSIVE
MANAGEMENT HIGHLY DISTURBED COVERED
SOILS URBAN CLIMATE CHANGE/POLLUTANTS REMNANT
PATCHES
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DISTURBED AND MADE SOILS
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SOIL DISTURBANCE EFFECTS?
1. SOIL PHYSICAL DISTURBANCES MIXING AND
COMPACTION DISRUPTION OF SOIL AGGREGATES
DRAINAGE 2. BURIAL AND COVERAGE OF SOIL
LAND FILL IMPERVIOUS SURFACES REDUCED
AERATION 3. LOSS OF SURFACE HORIZONS (EROSION)
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BALTIMORE COUNTY
?
2600 m2
TOP SOIL?
DISTURBED SOIL
SUB SOIL
2.7 x 104 kg SOC
McGuire (2004)
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MADE SOIL ORGANIC C PEDON DATA
C DENSITY (kg m-2)
MADE SOIL TYPE
n
REFUSE 2 17.2 (3.3) CLEAN FILL 8 2.8
(1.0) DREDGE (RECENT) 1 24.7 DREDGE (OLD) 4
3.8 (0.3)
n of pits L. Hernandez, NRCS, NYC Soil
Survey (NEW YORK CITY) D. Fanning, J.R. Short
(WASHINGTON DC AND BALTIMORE)
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BALTIMORE CITY
2.00
1.80
r 0.52 P lt 0.0001
1.60
1.40
1.20
Bulk Density (Mg m-3)
1.00
0.80
0.60
0-5 cm
0.40
n 126
0.20
10 land-use types
0.00
0
2
4
6
8
10
12
14
SOM ()
Pouyat et al. 2001
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MANAGEMENT/SITE HISTORY?
Supplements
Clipping
Erosion
Cultivation
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MARYLAND, USA TURFGRASS MAINTENANCE COSTS
(MANAGEMENT EFFORT VARIES!)
COST PER ACRE (IN U.S. DOLLARS)
LAND-USE TYPE
GOLF COURSES 2,727 LAWN CARE
FIRMS 1,969 ATHLETIC FIELDS 1,155 PARKS
450 DETACHED HOMES 369 CHURCHES 166
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Lawn Carbon Densities
n 2
Recreational use/grass
n 4
Residential grass
n 6
Park use/grass
0
10
20
30
2
Carbon Density (Kg/m
)
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)
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• Management/Cover
• Site history

From Qian and Follet (2002)
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AGE SINCE DEVELOPMENT
12
10
8
Woody Vegetation C
Carbon (kg m-2)
Lawn Stubble C
6
SOC 0-10 cm
4
SOC 10-20 cm
SOC 20-30 cm
2
Veg n53 sites total (not all represented
here) Soil n 14 sites total
0
Grass- land
1990s
AGRIC.
1950s
1960s
1970s
1980s
Land Use or Decade of Development
Golubiewski and Wessman, 2004, submitted
Golubiewski and Wessman (2004, submitted)
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BALTIMORE COUNTY
10.0
10.0
P 0.09
1970 (n11, lawns)
1980 (n13, lawns)
7.5
7.5
0-5 cm
SOM g/100g
5.0
5.0
2.5
2.5
0.0
0.0
OM
pH
Yesilonis, Pouyat, Russell-Anelli
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URBAN ENVIRONMENTAL CHANGE

• 1. Altered temperature regimes
• 2. Introduction of pollutants
• - Toxic and sub lethal effects
• - Fertilization (CO2, N deposition)
• 3. Introduction of non-natives
• - Litter quality
• - Keystone species (earthworms)
• 4. Altered hydrologic processes

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RESPONSE ALONG URBAN-RURAL GRADIENT IN NEW YORK
CITY
URBAN RURAL
URBAN RURAL
Soil Pb, Cu, Ni Soil Ca, Mg,Total salts Soil
Temperature N, S, Ca, Mg deposition Exotic
Earthworms/Mull
Fungi Microinverts Mor soils Litter quality
Pouyat et al 1995
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SOIL C POOLS (0-15 cm) Pool Urban
Rural 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)
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SOIL ORGANIC C ?
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?
Remnant soils?
p
Data in Pouyat et al. 2003
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Net Change SOC in Hypothetical 1000 ha Urban
Landscape
Pre-Agriculture Pre-Urban (Ag) Urban
kg C
4.17 x 10-6 2.59 x 10-6 2.36 (?) x 10-6
6.31 x 10-6 6.26 x 10-6 5.06 x 10-6
Mid-Atlantic Southeast Southwest
11.56 x 10-6 7.74 x 10-6 1.4 x 10-6
soil organic carbon density to 1 m depth (kg C
m-2) data for forest and crop SOC from Birdsey
(1992)
Land-use and impervious cover data for 58 cities
USA (Nowak et al., 1996)
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1 m DEPTH SOIL CORES
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BALTIMORE CITY
n plots (3 cores/plot)
N
n
Pouyat, Yesilonis and Russell-Anelli
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BURIED A HORIZONS?
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Ecotope Mapping
Historic Air Photos
Stratify Samples
Change Analysis
E. Ellis
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CONCLUSIONS

• SOC pools vary widely in urban mosaic
• 2. Management use affect SOC pools
• SOC pools disturbances ?, management ?
• Net 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)

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