Data for: Spruce budworm defoliation impact on greenhouse gas concentrations in streams [Gaspésie, Quebec, 2023-2024]

This dataset includes greenhouse gases (GHG) concentrations—specifically carbon dioxide (CO₂), methane (CH₄), and nitrous oxide (N₂O)—collected from 12 headwater streams located in the Gaspésie Peninsula, Quebec, Canada. The data capture the GHG response of these streams to varying levels of forest defoliation and mortality caused by the ongoing eastern spruce budworm (Choristoneura fumiferana) outbreak, which began in the region in 2016. Sampling was conducted 11 times between June and October in both 2023 and 2024. In addition to GHG concentrations, the dataset includes physical, chemical, and climatic variables (e.g., stream slope, flow, nutrient concentrations, precipitation) that may also influence GHG concentrations in these pristine headwater streams.