A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Contrasting soil nitrogen dynamics across a montane meadow and urban lawn in a semi-arid watershed
Abstract Urbanization substantially increases nitrogen (N) inputs and hydrologic losses relative to wildland ecosystems, although the fate of N additions to lawns and remnant grasslands remains contested. In montane semi-arid ecosystems, N cycling is often closely coupled to snowmelt (the dominant period of infiltration) and snow cover, which impact soil temperature and moisture. Here, we compared soil N dynamics between a fertilized and irrigated urban lawn and nearby riparian meadow in Salt Lake City, Utah during a snow manipulation experiment. Snow removal increased freeze/thaw events but did not affect N pools, microbial biomass, denitrification potential, or soil oxygen ($ O_{2} $). Mineral N was similar between sites despite lawn fertilization, but dissolved organic N (DON) was four-fold greater (2.1 ± 0.1 mg N $ l^{−1} $) in lawn soil water. Infiltration was lower in the lawn subsoil, and leaching losses (modeled with Hydrus) were small at both sites (< 2 kg N $ ha^{−1} $ $ y^{−1} $) despite substantial lawn fertilization. Lawn soil $ O_{2} $ fluctuated between 20.9 and 1.6 % following snowmelt and irrigation, but remained near 20 % in the meadow; the lawn had more reducing microsites as indicated by iron speciation. Post-snowmelt potential denitrification was six-fold greater in the lawn than the meadow. Lawns can potentially provide hotspots of denitrification in a semi-arid landscape that exceed some natural riparian ecosystems, whereas DON may represent an increasingly important form of N loss from lawns.
Contrasting soil nitrogen dynamics across a montane meadow and urban lawn in a semi-arid watershed
Abstract Urbanization substantially increases nitrogen (N) inputs and hydrologic losses relative to wildland ecosystems, although the fate of N additions to lawns and remnant grasslands remains contested. In montane semi-arid ecosystems, N cycling is often closely coupled to snowmelt (the dominant period of infiltration) and snow cover, which impact soil temperature and moisture. Here, we compared soil N dynamics between a fertilized and irrigated urban lawn and nearby riparian meadow in Salt Lake City, Utah during a snow manipulation experiment. Snow removal increased freeze/thaw events but did not affect N pools, microbial biomass, denitrification potential, or soil oxygen ($ O_{2} $). Mineral N was similar between sites despite lawn fertilization, but dissolved organic N (DON) was four-fold greater (2.1 ± 0.1 mg N $ l^{−1} $) in lawn soil water. Infiltration was lower in the lawn subsoil, and leaching losses (modeled with Hydrus) were small at both sites (< 2 kg N $ ha^{−1} $ $ y^{−1} $) despite substantial lawn fertilization. Lawn soil $ O_{2} $ fluctuated between 20.9 and 1.6 % following snowmelt and irrigation, but remained near 20 % in the meadow; the lawn had more reducing microsites as indicated by iron speciation. Post-snowmelt potential denitrification was six-fold greater in the lawn than the meadow. Lawns can potentially provide hotspots of denitrification in a semi-arid landscape that exceed some natural riparian ecosystems, whereas DON may represent an increasingly important form of N loss from lawns.
Contrasting soil nitrogen dynamics across a montane meadow and urban lawn in a semi-arid watershed
Hall, Steven J. (author) / Baker, Michelle A. (author) / Jones, Scott B. (author) / Stark, John M. (author) / Bowling, David R. (author)
Urban Ecosystems ; 19
2016
Article (Journal)
Electronic Resource
English
BKL:
43.31
Naturschutz
/
42.90$jÖkologie: Allgemeines
/
43.31$jNaturschutz
/
42.90
Ökologie: Allgemeines
/
74.12
Stadtgeographie, Siedlungsgeographie
/
74.12$jStadtgeographie$jSiedlungsgeographie
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