Lejla Latifovi, M. Altaf Arain (2022). The Impact of a Gypsy Moth Defoliation Event on Net Ecosystem Productivity in a Mature Deciduous Forest in Southern Ontario. Proceedings of the GWF Annual Open Science Meeting, May 16-18, 2022.

Temperate forests are an important global carbon sink. However, various environmental disturbances can impact carbon sequestration. An invasive defoliation attack by the gypsy moth (Lymantria dispar L.) during the growing season of 2021 decimated a mature oak-dominated forest stand situated north of Lake Erie in Southern Ontario, Canada. This forest is >90 years old and is know as CA-TPD site in the Global Water Futures and global FLUXNET networks. In this study, we quantify the extent and severity of the forest disturbance (defoliation) using eddy covariance measurements of net ecosystem productivity (NEP), gross primary productivity (GPP), and ecosystem respiration (RE) in the forest.

Previous research at our site indicated a strong carbon sink suggesting that sequestration capabilities of the forest were resilient to environmental stresses. On average, between 2012 and 2016, the forest was an annual carbon sink of 206 ± 92 g C m-2 yr-1. Current research examines how continued climate variability and the sever attack by Lymantria dispar impacted carbon dynamics and the potential of the stand to remain a strong carbon sink.

The extent to which North American temperate forests remain an important carbon sink will depend on the severity and rate of recovery from forest disturbance and extreme weather events under a changing climate.

AOSM2022 First Author: Lejla Latifovic, McMaster University Additional Authors: M. Altaf Arain, McMaster University