Boreal black spruce forests contribute to climate change mitigation by accumulating large amounts of carbon (C) in moss-derived peat. When left undisturbed, a thick peat layer can inhibit tree growth, and this trade-off between peat and tree biomass can have implications on the forest C dynamics. Similarly, wildfire severity and frequency can modify C accumulation patterns, but this impact remains poorly documented. We used the Carbon Budget Model of the Canadian Forest Sector version 3 (CBM-CFS3) to explore over a 400-year simulation period, the effects of high-severity fire (HSF) and low-severity fire (LSF) on C dynamics of two forest types (black spruce?Sphagnum (BSSP) and black spruce?feathermoss (BSFM)). We found that total C stocks increased to higher levels after LSF than after HSF in BSSP due to peat accumulation. Conversely, in BSFM, HSF resulted in greater C storage than LSF due to tree biomass. The tree component is key to the rapid recovery of C pools in both BSSP and BSFM forests specifically after HSF, while mosses maintain C sinks over the long term. This study suggests that a good characterization of forest type is key to better predictions of the effects of a change in fire regime on ecosystem C dynamics.

Beavers, as ecosystem engineers, create crucial wetlands and habitats for other species, altering the structure and function of the surrounding forests and affecting human infrastructure. However, despite these significant economic and ecological implications, the spatiotemporal patterns of beaver feeding strategies remain understudied. This study aimed to evaluate how forest stand type, lake size, and diet influence beaver territorial occupation in eastern Canada. We used a dendroecological approach to measure beaver occupation time and maximum browsing distance around 61 lakes. Around each beaver lodge, we established 1 m² plots along three transects in which we measured distance of browsing from shore and counted annual rings on coppices resulting from beaver presence. PERMANOVA revealed that both maximum browsing distance ( p = 0.003) and temporal occupation ( p = 0.006) differed significantly across lake size categories. The type of forest stand had no impact on beaver dynamics. Stable isotope analysis (δ13C and δ15N) of beaver carcasses collected from local trappers showed that the beavers’ diet included the consumption of conifer trees and a seasonal shift in food consumption. We found that lakes ranging from 4 to 20 ha were optimal for beavers, as this lake size mattered more than the availability of specific food sources. Beavers exhibited high adaptation skills by using different plant species depending on the season to maximize resource availability and energy cost trade-off. Understanding the factors involved in beaver territorial occupation dynamics is crucial for land managers and conservationists to effectively incorporate this species into forest management plans and mitigate beaver–human conflicts.