Harvesting interacts with climate change to affect future habitat quality of a focal species in eastern Canada’s boreal forest

Abstract

Many studies project future bird ranges by relying on correlative species distribution models. Such models do not usually represent important processes explicitly related to climate change and harvesting, which limits their potential for predicting and understanding the future of boreal bird assemblages at the landscape scale. In this study, we attempted to assess the cumulative and specific impacts of both harvesting and climate-induced changes on wildfires and stand-level processes (e.g., reproduction, growth) in the boreal forest of eastern Canada. The projected changes in these landscape- and stand-scale processes (referred to as “drivers of change”) were then assessed for their impacts on future habitats and potential productivity of black-backed woodpecker (BBWO; Picoides arcticus), a focal species representative of deadwood and old-growth biodiversity in eastern Canada. Forest attributes were simulated using a forest landscape model, LANDIS-II, and were used to infer future landscape suitability to BBWO under three anthropogenic climate forcing scenarios (RCP 2.6, RCP 4.5 and RCP 8.5), compared to the historical baseline. We found climate change is likely to be detrimental for BBWO, with up to 92% decline in potential productivity under the worst-case climate forcing scenario (RCP 8.5). However, large declines were also projected under baseline climate, underlining the importance of harvest in determining future BBWO productivity. Present-day harvesting practices were the single most important cause of declining areas of old-growth coniferous forest, and hence appeared as the single most important driver of future BBWO productivity, regardless of the climate scenario. Climate-induced increases in fire activity would further promote young, deciduous stands at the expense of old-growth coniferous stands. This suggests that the biodiversity associated with deadwood and old-growth boreal forests may be greatly altered by the cumulative impacts of natural and anthropogenic disturbances under a changing climate. Management adaptations, including reduced harvesting levels and strategies to promote coniferous species content, may help mitigate these cumulative impacts.

Projected effects of climate change on boreal bird community accentuated by anthropogenic disturbances in western boreal forest, Canada

“…Indeed, boreal climate conditions are expected to shift northward and upward with warming temperatures, with an expected contraction of the boreal biome of up to 42% by the end of this century (Rehfeldt et al, 2012; Stralberg et al, 2019). As many boreal bird species are dependent on specific habitats to complete their life cycles, shifts in the extent and distribution of boreal vegetation are likely to strongly influence bird communities over the coming decades (Cadieux et al, 2019; Rodenhouse et al, 2008; Stralberg et al, 2019; Stralberg, Matsuoka, et al, 2015; Tremblay et al, 2018). Indeed, large declines of climatically suitable boreal bird habitat have been projected for both North American (Stralberg, Bayne, et al, 2015) and Scandinavian species (Virkkala, Heikkinen, Leikola, & Luoto, 2008).…”

Conservation planning for boreal birds in a changing climate: a framework for action

“…Furthermore, for boreal-breeding species, changes in breeding niches are projected to be more substantial on average than changes in wintering niches (Naujokaitis-Lewis 2014, Langham et al 2015). Some species with the largest projected loss of climatic niche space include boreal forest specialists like Black-backed Woodpecker (Picoides arcticus; Tremblay et al 2018), Gray-cheeked Thrush (Catharus minimus;), Bicknell's Thrush (Catharus bicknelli; Rodenhouse et al 2008, Cadieux et al 2019, Rusty Blackbird (Euphagus carolinus; , Blackpoll Warbler (Setophaga striata; Ralston and Kirchman 2013), and Palm Warbler (Setophaga palmarum; Langham et al 2015. In comparison, many boreal species that nest in deciduous stands also have ranges that extend south into eastern deciduous forests.…”

“…For example, impacts of climate change are likely to be detrimental for Black-backed Woodpecker, an indicator species for deadwood and old-growth biodiversity in eastern boreal forests (Tremblay et al 2009(Tremblay et al , 2010. Indeed, simulations of landscape change suggest up to a 92% decline in potential productivity for this species under all climatechange scenarios considered, primarily based on increased levels of natural and anthropogenic disturbance in the future (Tremblay et al 2018).…”

“…Landscape simulation frameworks such as LANDIS-II Mladenoff 2004, Scheller et al 2007) and ALFRESCO (Rupp et al 2000) include modules to simulate stand-, e.g., forest succession or growth, and landscapescale, e.g., natural and anthropogenic disturbances, processes at meaningful temporal and spatial scales, allowing for the characterization of wildlife habitats (Rupp et al 2006). Furthermore, despite significant scale challenges (Cushman et al 2007), landscape simulation models can be used to simulate the impact of climate change on various ecological processes (Scheller et al 2007), and may be useful to predict the impacts of changing climate on bird habitats (Marcot et al 2015, Tremblay et al 2018, Cadieux et al 2019. By incorporating spatial legacies of the landscape, future dynamics of forest disturbances, and trajectories of vegetation succession, landscape simulation models can provide more realistic projections of bird habitats than species distribution models alone (De Cáceres et al 2013, Vissault 2016.…”

Climate change, woodpeckers, and forests: Current trends and future modeling needs

“…Dynamic community process‐based forest landscape models (Scheller & Mladenoff, ) such as the LANDIS models (LANDIS‐II and LANDIS PRO; Figure a) that incorporate finer scale climate–vegetation–disturbance interactions compared to bioclimatic DGVMs are ideally suited for this integration (Di Febbraro et al, ; Iverson, Prasad, Matthews, & Peters, ; LeBrun et al, ; Tremblay, Boulanger, Cyr, Taylor, & Price, ). These models could improve woodpecker distribution modeling, especially within the context of multi‐objective management scenarios (Martin, Hurteau, Hungate, Koch, & North, ).…”