Abstract:
One-meter soil cores were taken to evaluate soil texture, bulk
density, carbon and nitrogen pools, microbial biomass carbon and
nitrogen content, microbial respiration, potential net nitrogen
mineralization, potential net nitrification and inorganic nitrogen
pools in 32 residential home lawns that differed by previous land use
and age, but had similar soil types. These were compared to soils from
8 forested reference sites.
Purpose:
Soil cores were obtained from residential and forest sites in the
Baltimore, MD USA metropolitan area. The residential sites were mostly
within the Gwynns Falls Watershed (-76.012008W, -77.314183E,
39.724847N, 38.708367S and approximately 17 km2) Lawns on residential
sites were dominated by a variety of cool season turfgrasses. Forest
soil cores were taken from permanent forest plots of the Baltimore
Ecosystem Study (BES) LTER (Groffman et al. 2006). These remnant
forests are over 100 years old with soils that were comparable in type
and texture to those underlying the residential study sites. Soils
from all sites were from the Manor series (coarse-loamy, micaceous,
mesic Typic Dystrudepts), which are well-drained upland soils with
loamy textures and bedrock at 5 to 10 feet below the soil surface.
To aid the site selection process we used neighborhoods in the
Baltimore City metropolitan area that have been mapped using HERCULES,
a high resolution land cover classification system designed to assist
in the study of human-ecological systems (Cadenasso et al. 2007).
Using HERCULES and additional data sources, we identified residential
sites that were similar except for single factors that we hypothesized
to be important predictors of ecosystem dynamics. These factors
included land use history (agriculture and forest, n = 10 and n = 22),
housing density (low and medium/high, n = 9 and n = 23), and housing
age (4 to 58 yrs old, n = 32). Housing age was acquired from the
Maryland Property View database. Prior land use was determined based
on land use change maps developed by integrating aerial photos from
1938, 1957, 1971, and 1999 into a geographic information system. Once
a list of residential parcels meeting the predefined criteria were
identified, we sent mailings to property owners chosen at random from
each of the factor groups with the goal of recruiting 40 property
owners for a 3 year study (of which this work is a part). We had
recruited 32 property owners at the time that soil cores were
obtained.
Data have been published in Raciti et al. (2011a, 2011b)
References
Cadenasso, M. L., S. T. A. Pickett, and K. Schwarz. 2007. Spatial
heterogeneity in urban ecosystems: reconceptualizing land cover and a
framework for classification. Frontiers in Ecology and the Environment
5:80-88.
Groffman, P. M., R. V. Pouyat, M. L. Cadenasso, W. C. Zipperer, K.
Szlavecz, I. D. Yesilonis, L. E. Band, and G. S. Brush. 2006. Land use
context and natural soil controls on plant community composition and
soil nitrogen and carbon dynamics in urban and rural forests. Forest
Ecology and Management 236:177-192.
Raciti, S. R., P. M. Groffman, J. C. Jenkins, R. V. Pouyat, and T. J.
Fahey. 2011a. Controls on nitrate production and availability in
residential soils. Ecological Applications:In press.
Raciti, S. R., P. M. Groffman, J. C. Jenkins, R. V. Pouyat, T. J.
Fahey, M. L. Cadenasso, and S. T. A. Pickett. 2011b. Accumulation of
carbon and nitrogen in residential soils with different land use
histories. Ecosystems 14:287-297.
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Ecological homogenization of soil properties in the American residential macrosystem
The conversion of native ecosystems to residential ecosystems dominated by lawns has been a prevailing land‐use change in the United States over the past 70 years. Similar development patterns and management of residential ecosystems cause many characteristics of residential ecosystems to be more similar to each other across broad continental gradients than that of former native ecosystems. For instance, similar lawn management by irrigation and fertilizer applications has the potential to influence soil carbon (C) and nitrogen (N) pools and processes. We evaluated the mean and variability of total soil C and N stocks, potential net N mineralization and nitrification, soil nitrite (NO2−)/nitrate (NO3−) and ammonium (NH4+) pools, microbial biomass C and N content, microbial respiration, bulk density, soil pH, and moisture content in residential lawns and native ecosystems in six metropolitan areas across a broad climatic gradient in the United States: Baltimore, MD (BAL); Boston, MA (BOS); Los Angeles, CA (LAX); Miami, FL (MIA); Minneapolis–St. Paul, MN (MSP); and Phoenix, AZ (PHX). We observed evidence of higher N cycling in lawn soils, including significant increases in soil NO2−/NO3−, microbial N pools, and potential net nitrification, and significant decreases in NH4+pools. Self‐reported yard fertilizer application in the previous year was linked with increased NO2−/ NO3−content and decreases in total soil N and C content. Self‐reported irrigation in the previous year was associated with decreases in potential net mineralization and potential net nitrification and with increases in bulk density and pH. Residential topsoil had higher total soil C than native topsoil, and microbial biomass C was markedly higher in residential topsoil in the two driest cities (LAX and PHX). Coefficients of variation for most biogeochemical metrics were higher in native soils than in residential soils across all cities, suggesting that residential development homogenizes soil properties and processes at the continental scale.
more » « less- PAR ID:
- 10372684
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Ecosphere
- Volume:
- 13
- Issue:
- 9
- ISSN:
- 2150-8925
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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