Event Title

The role of edge effects in emerald ash borer infestation and forest regeneration

Event Type

Research Presentation

Academic Department

Biology, Environmental Studies

Location

Zoom: Pre-registration required

Event Website

https://hollins.zoom.us/meeting/register/tJErcumsrD0jGtzp1Rplx957Jdc_4Kd0-CYt

Start Date

6-4-2021 6:30 PM

Description

The emerald ash borer (EAB; Agrilus planipennis) is a buprestid beetle Native to Asia and now an invasive species in North America. EAB infests trees of the genus Fraxinus (ash), and has spread to 35 states since its introduction in the early-to-mid-1990s. EAB has the potential to functionally extirpate all native ash species within North America. Our study aims to characterize the ecological impacts of EAB infestation in Southwest Virginia, quantify the impact of edge effects on forest invasion and subsequent mortality of ash trees, as well as the role that forest edge effects play in forest regeneration post-ash tree mortality. In 2017, a total of 33 forest transects across 12 study sites located across the Roanoke Valley were established. Data was collected annually on woody species composition, growth, canopy position, and understory woody plant composition. Signs of EAB infestation and ash mortality were tracked at our ash sites across all study years as well. Although analyses are on-going, initial findings indicate significant increases in dieback scores of large (>12cm DBH) and small (<12cm DBH) trees across all years, indicating progressive mortality of ash trees. Trees in the core had significantly higher average dieback scores than trees in the edge in 2019, and large trees die more rapidly than small trees, particularly in 2019 and 2020. Finally, the mean number of seedlings at ash sites at the edge and core significantly decreased from 2017 to 2020 as ash mortality progressed. Additional analyses are underway to determine whether this might indicate a depletion of ash seeds in the seed bank.

Comments

Under the direction of Dr. Elizabeth R. Gleim.

Oral presentation; no poster provided.

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Apr 6th, 6:30 PM

The role of edge effects in emerald ash borer infestation and forest regeneration

Zoom: Pre-registration required

The emerald ash borer (EAB; Agrilus planipennis) is a buprestid beetle Native to Asia and now an invasive species in North America. EAB infests trees of the genus Fraxinus (ash), and has spread to 35 states since its introduction in the early-to-mid-1990s. EAB has the potential to functionally extirpate all native ash species within North America. Our study aims to characterize the ecological impacts of EAB infestation in Southwest Virginia, quantify the impact of edge effects on forest invasion and subsequent mortality of ash trees, as well as the role that forest edge effects play in forest regeneration post-ash tree mortality. In 2017, a total of 33 forest transects across 12 study sites located across the Roanoke Valley were established. Data was collected annually on woody species composition, growth, canopy position, and understory woody plant composition. Signs of EAB infestation and ash mortality were tracked at our ash sites across all study years as well. Although analyses are on-going, initial findings indicate significant increases in dieback scores of large (>12cm DBH) and small (<12cm >DBH) trees across all years, indicating progressive mortality of ash trees. Trees in the core had significantly higher average dieback scores than trees in the edge in 2019, and large trees die more rapidly than small trees, particularly in 2019 and 2020. Finally, the mean number of seedlings at ash sites at the edge and core significantly decreased from 2017 to 2020 as ash mortality progressed. Additional analyses are underway to determine whether this might indicate a depletion of ash seeds in the seed bank.

https://digitalcommons.hollins.edu/science_seminar/2021/presentations/13