Alter forest composition or structure to maximize carbon stocks

Structural and species diversity may buffer a community against the susceptibility of its individual components to climate change (Peterson et al. 1998). Biodiverse and multi-aged forest stands store more carbon relative to even-aged stands (Ammer 2018; Keeton et al. 2011) and can exhibit both resistance to disturbance-induced carbon loss and resilience when disturbances do occur, more quickly recovering carbon stocks over time (Duvenck and Scheller 2016; O’Hara and Ramage 2013). Substantially altering forest stand characteristics, including the creation of a greater mix of tree species, ages, size classes, and canopy complexity can improve the ability of forest stands to capture carbon through improved productivity, and well as reduce the risk of carbon loss (Ford and Keeton 2107). This may include introducing new species not currently found within existing forest communities, including moving species into new regions (e.g. assisted migration). While these actions may reduce the future disequilibrium between climate and a species’ traits, movement of species to new locations remains a challenging and contentious issue (Pedlar et al. 2012).

Land managers already work in many ways to increase forest productivity through enhancing structural heterogeneity and species diversity (Franklin et al. 2007). As an adaptation strategy for managing forest carbon, this general goal receives added effort and focus when managing systems whose current characteristics limit the ability of the forest to sequester carbon or increase the risk of carbon losses through disturbance under a changing climate (Fahey et al. 2018; Nagel et al. 2017). This strategy is focuses on altering the characteristics of a forest through intentional alterations of species composition and structure so the desired future conditions of the forest are significantly changed from current conditions (Millar et al. 2007; Swanston et al. 2016). These changes may be necessary in order to create ecosystems that are better adapted to the range of expected future conditions, thereby maintaining desired ecosystem services, including carbon sequestration and storage and reducing the risk of carbon loss from disturbance.