title: Emerald ash borer and the urban forest: Changes in landslide potential due to canopy loss scenarios in the City of Pittsburgh, PA.
abstract: Emerald ash borer is expected to kill thousands of ash trees in the eastern U.S. This research develops tools to predict the effect of ash tree loss from the urban canopy on landslide susceptibility in Pittsburgh, PA. A spatial model was built using the SINMAP (Stability INdex MAPping) model coupled with spatially explicit scenarios of tree loss (0%, 25%, 50%, and 75% loss of ash trees from the canopy). Ash spatial distributions were estimated via Monte Carlo methods and available vegetation plot data. Ash trees are most prevalent on steeper slopes, likely due to urban development patterns. Therefore, ash loss disproportionately increases hillslope instability. A 75% loss of ash resulted in roughly 800 new potential landslide initiation locations. Sensitivity testing reveals that variations in rainfall rates, and friction angles produce minor changes to model results relative to the magnitude of parameter variation, but reveal high model sensitivity to soil density and root cohesion values. The model predictions demonstrate the importance of large canopy species to urban hillslope stability, particularly on steep slopes and in areas where soils tend to retain water. To improve instability predictions, better characterization of urban soils, particularly spatial patterns of compaction and species specific root cohesion is necessary. The modeling framework developed in this research will enhance assessment of changes in landslide risk due to tree mortality, improving our ability to design economically and ecologically sustainable urban systems.
authors.affiliation: Department of Geology and Planetary Science, University of Pittsburgh, 4107 O'Hara Street, SRCC, Room 200, Pittsburgh, PA 15260-3332 USA. Electronic address: ekp9@pitt.edu.
authors.forename: Erin
authors.initials: E
authors.lastname: Pfeil-McCullough
authors.affiliation: Department of Geology and Planetary Science, University of Pittsburgh, 4107 O'Hara Street, SRCC, Room 200, Pittsburgh, PA 15260-3332 USA. Electronic address: dbain@pitt.edu.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Bain
authors.affiliation: Western Pennsylvania Conservancy Community Gardens & Greenspace Program, 800 Waterfront Drive Pittsburgh, PA 15222, USA. Electronic address: jbergman@paconserve.org.
authors.forename: Jeffery
authors.initials: J
authors.lastname: Bergman
authors.affiliation: Tree Pittsburgh, 5427 Penn Avenue, Pittsburgh, PA 15206, USA. Electronic address: danielle@treepittsburgh.org.
authors.forename: Danielle
authors.initials: D
authors.lastname: Crumrine
mesh_terms: D000818:Animals; D002947:Cities; D001517:Coleoptera; D031661:Fraxinus / Q000469:parasitology; D055876:Landslides / Q000706:statistics & numerical data*; D010414:Pennsylvania; D018570:Risk Assessment
keywords: Emerald ash borer; GIS; Geospatial modeling; Hillslope hydrology; Invasive species; Landslides; Root cohesion; Soil cohesion; Urban forests