Predicting carbon storage in North American maritime boreal forests under combined disturbances

ContextUnderstanding how forest disturbances, such as fire and herbivory, affect carbon storage across the landscape can help inform forest management and disturbance mitigation. However, this is made difficult by uncertainties in carbon predictions and limited records of disturbance histories.ObjectivesOur objectives were to predict carbon stocks and predict where disturbances have created open forest patches across the study areas, and to assess the relative effects of disturbances and subsequent moose herbivory on carbon stocks.MethodsWe used field measurements of carbon stocks and disturbances from a two-year field study on the island of Newfoundland, Canada, along with remotely sensed environmental variables (e.g., stand height, elevation), to predict spatial patterns in carbon stocks as well as predict where disturbances have created open forest across Gros Morne and Terra Nova National Parks.ResultsWe found that the remotely sensed variables of forest height and productivity were the most informative predictor variables for both carbon stocks and whether an area was an open forest. Our models predict less carbon in areas classified as open forest relative to areas classified as mature forest. Further, we observed that moose herbivory may impede the recovery of carbon stocks in open forests after disturbances, leading to a reduction in carbon storage of up to 13 megatonnes, or 40% of carbon predicted to be stored across the two national parks.ConclusionsOverall, we find there is potential to increase or maintain carbon storage in maritime boreal forests by limiting moose herbivory in areas regenerating following disturbance. This work adds to our understanding of drivers of forest carbon storage and can help inform boreal forest management to optimize carbon storage.