Despite interest in the contribution of evapotranspiration (ET) of residential turfgrass lawns to household and municipal water budgets across the United States, the spatial and temporal variability of residential lawn ET across large scales is highly uncertain. We measured instantaneous ET (ETinst) of lawns in 79 residential yards in six metropolitan areas: Baltimore, Boston, Miami, Minneapolis-St. Paul (mesic climates), Los Angeles and Phoenix (arid climates). Each yard had one of four landscape types and management practices: traditional lawn-dominated yards with high or low fertilizer input, yards with water-conserving features, and yards with wildlife-friendly features. We measured ETinst in situ during the growing season using portable chambers and identified environmental and anthropogenic factors controlling ET in residential lawns. For each household, we used ETinst to estimate daily ET of the lawn (ETdaily) and multiplied ETdaily by the lawn area to estimate the total volume of water lost through ET of the lawn (ETvol). ETdaily varied from 0.9 ± 0.4 mm d1 in mesic cities to 2.9 ± 0.7 mm d−1 in arid cities. Neither ETinst nor ETdaily was significantly influenced by yard landscape types and ETinst patterns indicated that lawns may be largely decoupled from regional rain-driven climate patterns. ETvol ranged from ∼0 L d−1 to over 2,000 L d−1, proportionally increasing with lawn area. Current irrigation and lawn management practices did not necessarily result in different ETinst or ETdaily among traditional, water-conserving, or wildlife-friendly yards, but smaller lawn areas in water-conserving and wildlife-friendly yards resulted in lower ETvol.
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The authors greatly appreciate all the homeowners who allowed us to take measurements in their yards. In Boston, the authors thank Brett Barnard and Emily Tanner for coordinating the field campaign and data management, and the Massachusetts Department of Conservation and Recreation and Mass Audubon for providing permission to work in natural and interstitial sites. In Minneapolis-St. Paul, the authors thank Christopher Buyarski for helping to coordinate the field campaign and data management, and the Minnesota Department of Natural Resources, the Nature Conservancy, Three Rivers Park District, the cities of Brooklyn Park, Eden Prairie, Arden Hills, and Ramsey County Parks and Recreation for providing permission to work in natural and interstitial areas. In Baltimore, the authors thank Laura Templeton for coordinating the field campaign and data management, Ben Glass-Seigel, Dan Dillon, Juan Botero, Katherine Ralston, and Alyssa Wellman Houde for fieldwork and Baltimore City, Baltimore County, and the State of Maryland for providing permission to work in interstitial and natural sites. In Miami, the authors thank Martha Zapata, Sarah Nelson, Sebastian Ruiz for fieldwork and Miami-Dade County Parks, Florida State Parks and Pine Ridge Sanctuary for providing permission to work in natural and interstitial areas. In Los Angeles, the authors thank UCLA/La Kretz Center for California Conservation Science, National Park Service, Los Angeles City Department of Recreation and Parks, the Audubon Center, Mountains Recreation and Conservation Authority, Palos Verdes Peninsula Conservancy for providing permission to work in natural and interstitial sites. In Phoenix, the authors thank Laura Steger for coordinating the field campaign and data management, Alicia Flores, John Talarico, and Brittany Strobel for fieldwork and Maricopa County Parks and Recreation Department, City of Scottsdale, and City of Phoenix for providing permission to work in natural and interstitial sites. The authors thank Mary Phillips and Erin Sweeney from the National Wildlife Federation for help accessing Wildlife Certified yards. The authors thank Alexander Vincent for rendering an artist impression of the yard landscape types. Lastly, the authors are very thankful for the thoughtful comments from two anonymous reviewers and the editors which greatly improved this manuscript.
© 2023. The Authors.
- lawn care practices
- residential landscapes
- water use
- yard type