Identifying trade‐offs and opportunities for forest carbon and wildlife using a climate change adaptation lens

Abstract

On a warming planet, a key challenge natural resource managers face is protecting wildlife while mitigating climate change—as through forest carbon storage—to the greatest extent possible. But in some ecosystems, habitat restoration for imperiled species may be incompatible with maximizing carbon storage. For example, promoting early successional forest conditions does not maximize stand‐level carbon storage, whereas uniformly promoting high stocking or mature forest conditions in the name of carbon storage excludes species that require open or young stands. Here, we briefly review the literature regarding carbon and wildlife trade‐offs and then explore four case studies from the Northern Forest region of the United States. In each case, human activities have largely dampened the influence of natural disturbances; restoring or emulating these disturbances is typically required for habitat restoration even when doing so equates to less carbon storage at the stand level. We propose that applying a climate adaptation lens can help managers and planners navigate these trade‐offs and steer away from maladaptive practices that may ultimately reduce adaptive capacity. Instead, critically evaluating the consequences of stand‐level management actions on both carbon and wildlife can then facilitate landscape‐scale climate adaptation planning that supports a diversity of habitats alongside opportunities to invest in maximizing forest carbon.

Forest-clearing to create early-successional habitats: Questionable benefits, significant costs

“…It is important to recognize that documentation of the decline of early-successional species is almost invariably based on a very recent baseline, generally dating to the 1960s or later (DeGraaf and Yamasaki, 2003;Massachusetts Audubon Society, 2013;North American Bird Conservation Initiative, 2014;Rosenberg et al, 2016Rosenberg et al, , 2017Rosenberg et al, , 2019Connecticut Department of Energy and Environmental Protection, 2019;Sauer et al, 2020;Littlefield and D'Amato, 2022). This time period is a convenient benchmark because it falls within the lived experience of many of today's wildlife and forest managers and the landowners and public that they are trying to reach.…”

“…Advocates of clearing forests for early-successional habitats assert that natural and pre-European disturbances have been greatly attenuated and, therefore, managers must step in to create them (DeGraaf and Yamasaki, 2003;Oehler et al, 2006;Fergus, 2014;King and Schlossberg, 2014;Littlefield and D'Amato, 2022). While these habitats are reduced from their zenith in the 1800s and early 1900s (Foster et al, 2002;Litvaitis, 2003;Lorimer and White, 2003), extensive early-successional habitats still exist and are continuously produced, naturally and by widespread human activity.…”

“…Forest-clearing advocates assert that, in parallel with the presumed lack of "young" forests, there is an overabundance of "mature, " and "even-aged" forests across the landscape. They contend that these forests do not provide an adequate diversity of habitats, and that "active management" can "restore" forest diversity and resiliency by "mimicking" natural forest disturbances and conditions (National Commission on Science for Sustainable Forestry, 2007;Fergus, 2014;King and Schlossberg, 2014;New Jersey Department of Environmental Protection, 2018;Rohrbaugh et al, 2020;Littlefield and D'Amato, 2022). Prior to evaluating this rationale it is important to note that a forest termed "even-aged" can include ages that vary by about 20% of the dominant age, and may also include young trees/advance regeneration, dead trees, and a mosaic of habitats (for example, due to insect damage or storms).…”

Carbon conundrums: Do United States' current carbon market baselines represent an undesirable ecological threshold?

“…In particular, Anderson‐Teixeira and Belair (2022) noted that scientists should help improve C accounting methodologies to enable more credible estimates of C mitigation potentials based on objective forest C baselines, which likely requires more rigorous assessments of forest C stocks and fluxes across both space and time. Beyond improving estimate credibility, there is a strong need to rectify incongruities between ecological conditions incentivized by C programs and maintaining key forest functions and attributes, including vulnerability to extreme climate and disturbance events (Hurteau et al, 2019), as well as wildlife habitat provisioning (e.g., Littlefield & D'Amato, 2022). For example, does maximizing forest C across the landscape now truly lead to long‐term C stability (i.e., minimizing risks of future emissions) for future generations as global change accelerates?…”

“…As our data suggests, IFM practices (as currently defined) inordinately focus on maximizing C storage in the present at the potential expense of future provisioning, while achieving net C benefits no greater than forests with more optimal densities and reduced emission risks. Moreover, the uniformity and higher stocking that existing basal area-based methodologies compel us towards may undermine future provisioning of critical forest ecosystem services and habitat (e.g., water, wildlife; Littlefield and D'Amato (2022)). We suggest that IFM could be improved by adopting more biologically relevant yet flexible metrics like RD and expanding research into explicit consideration of C transfers among live to dead biomass pools, incorporating more robust assessments of tradeoffs across space/time, and considering the long-term sustainability of the practice in light of emission risks such as forest loss due to disturbances exceeding the historic range of variability and/or exceeding adaptive capacity.…”