Implications of future disturbance regimes on the carbon balance of Canada’s managed forest (2010–2100)

Abstract

A B S T R A C T Recent increases in fire and insect disturbances have contributed to a transition of Canada's managed forest carbon balance from sink to source. Further increases in area burned could contribute positive feedback to climate change. We made probabilistic forecasts of the recovery of C sinks in Canada's managed forest between 2010 and 2100 under two assumptions about future area burned by wildfire: (1) no increase relative to levels observed in the last half of the 20th century and (2) linear increases by a factor of two or four (depending on region) from 2010 to 2100. Recovery of strong C sinks in Canada's managed forest will be delayed until at least the 2030s because of insect outbreaks, even if predicted increases in area annually burned do not occur. After 2050, our simulations project an annual probability of a sink near 70% with no increase in area burned and 35% with increasing area burned. All simulations project a cumulative C source from 2010-2100, even if annual area burned does not increase. If the sink strength of terrestrial ecosystems is reduced because of increasing natural disturbances, then it will become more difficult to achieve global atmospheric CO 2 stabilization targets.

Forest Carbon Sequestration: The Impact of Forest Management

“…Changes in the regimes of natural disturbances such as fire, pests or drought (Fuhrer et al, 2006, Sohngen et al, 2005, Ciais et al, 2005, can affect major forest functions, forestry outputs and forest stability. Metsaranta et al (2010) reported that Canadian forests will likely be carbon sources until 2030, and become carbon sinks after 2050, based on simulations of the impact of future fire and insect disturbances.…”

Area-Based Mapping of Defoliation of Scots Pine Stands Using Airborne Scanning LiDAR

“…This long-term loss in yield alters volume predictions from a forest management perspective, resulting in a need to revisit harvest scheduling and total fiber volume levels present over a given woodshed. Inventory-based estimates of volume are often statistically linked to biomass to produce modeled estimates of carbon that, in turn, can be used to inform on the exchange of gases between terrestrial ecosystems and the atmosphere (e.g., [16]). As such, capturing factors that perturb the capacity to accumulate fiber, such as defoliation, is increasingly important.…”

Increasing potential NEP of eastern boreal North American forests constrained by decreasing wildfire activity

“…These responses may further be altered by a second-order impact via changes in the age-class distribution and composition of forest landscapes that result from changes in the disturbance regime (Kashian et al 2006, Zaehle et al 2006, Metsaranta et al 2010. Boreal forests in their juvenile stage (age , 15 years) are usually carbon sources because of low leaf area and assimilation rates compared with on-going rates of decomposition.…”