Presentation on theme: "Getting ahead of the front Evaluating impacts of emerald ash borer (Agrilus planipennis) on forest vegetation in eastern North America Jason S. Kilgore,"— Presentation transcript:
Getting ahead of the front Evaluating impacts of emerald ash borer (Agrilus planipennis) on forest vegetation in eastern North America Jason S. Kilgore, Washington & Jefferson College Benjamin J. Dolan, The University of Findlay
Impacts thus far ●Altered light regime o Increases PAR and sapling growth (Burr & McCullough 2014) ●Altered nutrient cycling & carbon storage o Increase in non-ash productivity, particularly maples and elms o Productivity does not offset loss of regional ash productivity (Flower et al. 2013) ●Inconsistent response by species o Blue ash has higher survival rates than green ash (Tanis & McCullogh 2012)
EAB Impacts Study: hypotheses 1)Rate of ash decline (from EAB detection to mortality) is positively related to water stress via low precipitation and soil particle size across a continental-scale gradient. 1)Loss of ash from the overstory will allow more light to penetrate to the forest floor, resulting in an increase in density of seedlings and growth rate of saplings. 1)Light availability in high ash plots is sufficient to shift understory composition from shade-tolerant to more shade-intolerant tree species (Dolan et al., in prep; but see Flower et al. 2013). 1)Loss of ash will lead to increases in non-native invasive herbaceous and shrub species and cover (Hausman et al. 2010). 1)The presence and abundance of certain invasive plants (e.g., Alliaria petiolata, non-native Lonicera sp., Rosa multiflora, Rhamnus cathartica, and Ailanthus altissima) have a disproportionate effect on post- invasion diversity, growth rate of native trees, and time to canopy closure.
Understory variables (Subplot) Understory Community: ●Canopy cover ●Shrub/saplings (0.3-1.37 m tall) o Species, tally
Understory variables (Miniplot) Understory Community: ●Woody seedlings and herbaceous plants o Species, tally, cover class
Distribution vectors (GIS) Distances to: ●Major roads and expressways ●Streams and rivers ●Railroads ●Shipping ports ●Distribution centers and manufacturers receiving goods on foreign pallets
Data collection Undergraduate students ●Upper-level ecology or research courses ●General ecology, field biology, etc.
UF (Ohio) and W&J (Pennsylvania) ●Similar mature ash density (67-71 trees/ha) and overstory (22%) ●EAB documented in Hancock County (2005) and Washington County (2009) ●Ash mortality higher at UF (100%) than W&J (0%, but 23% with EAB symptoms) Initial results: mature ash