Abstract Detail



Ecology

Chapman, Julia [1], Buskey, Taylor [2], Kukla, Mitchell [2], Kuminecz, Corey [2], McEwan, Ryan [3].

Tree regeneration and herbaceous community responses to emerald ash borer-induced Fraxinus mortality and altered Alliaria petiolata abundance in an old-growth forest remnant.

Eastern North American deciduous forests are among the most diverse temperate ecosystems and are, unfortunately, threatened by the introduction of invasive species. In many places, it is common for multiple invading species to establish and impact native communities both directly via competition and indirectly by altering local environmental conditions. Drew Woods State Nature Preserve (DWSNP) is a 6-ha old-growth forest fragment in Darke County, Ohio that has been subjected to two major invasive species in the past decade. The emerald ash borer (EAB; Agrilus planipennis) is an invasive insect species in North America that has devastated Fraxinus (ash) populations in the Great Lakes region and has impacted the forest community in DWSNP. Garlic mustard (Alliaria petiolata) is an invasive herbaceous species that can reach high population densities and outcompete native plant species. As of 2012, Alliaria petiolata had attained high density in DWSNP; however, removal efforts have drastically reduced its density over the last 5 years. Our goal was to understand how all forest strata, from herbs to trees, have been changing through time in response to EAB-related tree mortality and the removal of A. petiolata. Thirty-two nested plots were established in DWSNP in 2011 to sample the overstory layer (314 m2; stems ≥ 2.5 cm diameter at breast height), sapling layer (10 m2; stems < 2.5 cm dbh and > 50 cm in height), seedling layer (1 m2; stems <50 cm in height), and herbaceous layer (1 m2; non-woody species). Woody strata were sampled in 2011 and 2017, and the herbaceous layer was sampled annually from 2012 to 2017. Overstory basal area of live Fraxinus decreased from 151.4 m2 ha-1 in 2011 to 1.68 m2 ha-1 in 2017 while dead Fraxinus increased from 33.5 m2 ha-1 to 132.3 m2 ha-1. Herbaceous species richness and cover were higher in more recent sampling years, likely due to increasing light availability via canopy gap formation, which is a driver of herbaceous diversity. Temporal beta diversity of the herbaceous layer was highest in plots with the highest reduction of A. petiolata densities. Further analyses will investigate how the abundances of tree species other than Fraxinus have changed during this time period. Simultaneous invasion of North American deciduous forests by exotic insects and plants is likely to continue as a pervasive phenomenon, and understanding long-term effects of both invasion and management activities will require a focus on interactive effects.


1 - 1519 Tabor Ave. Apt. C, Kettering, OH, 45420, United States
2 - University of Dayton, Department of Biology, 300 College Park, SC 211, Dayton, OH, 45469-2320, USA
3 - Biology, 300 College Park, Dayton, OH, 45469, United States

Keywords:
emerald ash borer
garlic mustard
old-growth
forest
herbaceous layer
overstory
invasive
community ecology.

Presentation Type: Oral Paper
Number:
Abstract ID:238
Candidate for Awards:Ecological Section Best Graduate Student Paper


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