Food web approach for managing Arctic wildlife populations in an era of rapid environmental change

Abstract

Scientists and wildlife managers implementing adaptive monitoring and management schemes, are tasked with providing predictions of population responses to harvest and environmental changes. Such predictions are useful not only to forecast direct effects of climate, productivity, land use, or habitat degradation, but also changes in the food web, such as expanding/�increasing species that are predators, prey, and competitors of populations of concern. Explicit consideration of food webs and their dynamics in more complex models could provide better predictions of future changes, and allow us to better assess the influence of management actions. Here, we present our perspective on what we have learned from conducting a number of case studies using such a food web approach with a focus on climate and harvest impacts and their implications for management. We found empirical support for many of our hypothesized food web effects, and were able in some cases to obtain short-term forecasts with slightly lower prediction error using models that account for food web dynamics compared with simpler models. Predictions are the foundation of adaptive management because they allow quantitative assessment of the effects of management actions; however, evaluating predictions requires adequate and high-quality monitoring data. Results from our case studies show that a combination of long-term monitoring and different types of study designs coupled with models of adequate complexity are likely required to better understand populations’ responses to environmental changes and harvest, as well as the consequences for food webs.

Ecological implications of the pink salmon invasion in northern Norway—Aggregative responses and terrestrial transfer by white‐tailed eagles

“…Furthermore, the impact of pink salmon on endemic wildlife through effects on scavenger numerical and functional responses is expected to depend on the abundance of non‐migratory alternative prey. In particular, the abundance of small rodents has been shown to influence predator impacts on endemic wildlife (Henden et al., 2021 ; Marolla et al., 2019 ; Mellard et al., 2022 ) and is therefore also expected to affect the consequences of pink salmon on endemic wildlife through the scavenger community.…”

“…shown to influence predator impacts on endemic wildlife (Henden et al, 2021;Marolla et al, 2019;Mellard et al, 2022) and is therefore also expected to affect the consequences of pink salmon on endemic wildlife through the scavenger community. UiT-the Arctic University of Norway (Bonde, 2023).…”

Five decades of terrestrial and freshwater research at Ny-Ålesund, Svalbard

“…We further recommend gaining an understanding of the effects of environmental change on food webs, identifying trophic cascades within and across ecosystems, and measuring C and nutrient fluxes between soils, atmosphere, freshwaters and the marine environment. These goals require the multidisciplinary research approaches that characterize the four Ny-Ålesund flagship programmes (Gabrielsen et al 2009;Coulson et al 2010;Neuber et al 2011;Svalbard Science Forum 2012) and the adaptive ecosystem-based ecological monitoring approach of the Climate-ecological Observatory for Arctic Tundra (Ims et al 2013;Ims & Yoccoz 2017;Mellard et al 2021). By focusing on these research needs, the international research community at Ny-Ålesund will provide globally relevant contributions to understanding the functioning of, and changes to, High-Arctic terrestrial and freshwater ecosystems, and their linkages with climate, glacial habitats and marine ecosystems.…”

Policy documents considering biodiversity, land use, and climate in the European Arctic reveal visible, hidden, and imagined nexus approaches

“…Interactions and dynamics between organisms change, with potential knock-on effects across trophic levels. 5 Plants grow faster and taller and at higher altitudes than one human generation ago. [6][7][8] Other Arctic biodiversity transitions 9 include changes in phenology (timing of leaf emergence, flowering/senescence of plants), vegetation composition, and plant traits (e.g., leaf and stem characteristics), all of which contribute to the overall functional diversity.…”