Farbod Tabaei, M. Altaf Arain (2022). The Carbon Exchange Dynamics of Young Temperate Coniferous Forests and its Response to Partial Thinning. Proceedings of the GWF Annual Open Science Meeting, May 16-18, 2022.

The vital role of forests in the global carbon cycle is well-established, but the influence of management practices on forest carbon dynamics remains overlooked. Forest thinning is a common practice conducted following afforestation or stand plantation to sustain and improve the carbon sequestration rates of the forest ecosystem. Using the eddy covariance (EC) method, this study investigates the impacts of thinning on the forest carbon exchange. In January 2021, selective thinning was conducted on a 48-year-old white pine (Pinus strobus) plantation in Southern Ontario, Canada, to remove approximately 20% of the trees on site. By utilizing eddy covariance CO2 fluxes and meteorological measurements, gross primary productivity (GPP), ecosystem respiration (RE) and net ecosystem productivity (NEP) were estimated following thinning. Study results will show the extent of changes in CO2 fluxes by comparing them to data from the previous nine years. Previous studies conducted on an adjacent 83-year-old white pine plantation indicated insignificant effects of thinning, and small reduction of NEP primarily due to increased RE in the first post-thinning year while stand remained a net carbon sink. A complete understanding of the response of forest carbon dynamics to thinning in young plantation forests is critical to guiding future forest management efforts. Further, past research has indicated improved tolerance to droughts following thinning, providing the potential to enhance carbon sequestration rates and growth in temperate coniferous forests.

First Author: Farbod Tabaei, McMaster Centre for Climate Change
Additional Authors: M. Altaf Arain, McMaster Centre for Climate Change