Increase harvest frequency or intensity due to greater risk of tree mortality

Decreasing carbon stocks may provide carbon benefits in scenarios where risk of carbon loss from disturbance is high. A changing climate may increase the frequency or magnitude of disturbances such as drought, fire, or insect damage he can result in widespread or high rates of tree mortality. A reduction in stand-level carbon stocks may decrease risks of carbon losses where stand conditions increase the vulnerability to disturbance-related mortality. Shortening rotation lengths in even-aged stands may provide the greatest long-term carbon benefit by maintaining moderate levels of ecosystem carbon stocks while minimizing the risk of large carbon losses if disturbance does occur. For example, projected growth declines from water limitations in managed boreal jack pine (Pinus banksiana) forests could result in greater carbon sequestration from a reducing rotation length from 79-80 years to 50 years. Shortening rotation lengths have additionally been shown to benefit aboveground biomass in stands with an increased risks of carbon loss to fire or ice storms. Shortening rotation lengths may also provide increased opportunities for harvesting wood products and transitioning the system to a species composition better adapted to future conditions, increasing overall forest carbon over long time periods. Likewise, shortening rotations increases the number of generations with the potential to increase the genetic adaptation of a species in future climate conditions. In cases of shortening rotations of maladapted species, prompt reforestation should occur in order to quickly initiate carbon sequestration. Likewise, if risk of disturbance is high, practices that decrease carbon stocks through reductions in stand densities (e.g., thinning) may lower the vulnerability to carbon losses from drought while increasing carbon sequestration rates through improved residual stand growth and understory carbon stocks, potentially without decreasing stand-level carbon stocks over longer time frames. Additionally, reducing stand densities can decrease susceptibility to damage from wind and ice storms.

Climate change is projected to increase the potential for severe disturbance events that reduce forest ecosystems carbon stocks, while additionally affecting the growth and regeneration of extant species. Many forest management decisions aim to limit the negative impacts of disturbances while enhancing the growth of residual trees and the regeneration of desired species that represent the current and future capacity of the ecosystem to sequester carbon. Often these management actions aim to enhance existing forest conditions, such as species composition and stand structural diversity that are key to the desired services provided by the forest. Slight adjustments in forest conditions can improve the retention of carbon within various forest carbon pools or enhance the rate of recovery following a disturbance event without dramatically altering the character of forest ecosystems.