Context matters when rewilding for climate change

Abstract

There is a cross-sectoral push amongst conservation practitioners to simultaneously mitigate biodiversity loss and climate change, especially as the latter increasingly threatens the former. Growing evidence demonstrates that animals can have substantial impacts on carbon cycling and as such, there are increasing calls to use animal conservation and trophic rewilding to help dually overcome biodiversity loss and climate change. Trophic rewilding is a complex conservation approach to mitigating climate change because it requires accurate baseline estimates of carbon cycling and species impacts on a system, social support for the project, and the actual reintroduction of a species. We join the growing excitement around this potential but caution that rewilding cannot always be justified on carbon benefits alone: a species’ net impact on ecosystem carbon dynamics is context dependent. The need for caution intensifies whenever biodiversity conservation (including rewilding), climate change mitigation, and human welfare do not readily align. Hence, these burgeoning efforts must avoid sweeping generalizations. To bolster reliable outcomes, we highlight the regional social and ecological context dependencies that can drastically vary outcomes in a rewilded carbon cycle and provide ethical considerations for successful implementation. We conclude with an overview of the available technology to predict and monitor progress toward both biodiversity and climate mitigation goals.

Plant mycorrhizal associations mediate the zoogeochemical effects of calving subsidies by a forest ungulate

“…For instance, reindeer grazing can have pronounced effects on soil biogeochemical processes in boreal forest and tundra ecosystems dominated by EcM and ErM plants (Castaño et al, 2023;Vowles, Lovehav, et al, 2017;Ylänne et al, 2015), but the effects of parturition remain unknown. Regardless of the exact mechanism or species, our study demonstrates how fine-scale differences in plant and fungal community composition can mediate the effects of a large N pulse (McCary et al, 2021) and highlights the need to consider context dependency, such as ecosystem management or disturbance in future zoogeochemical studies (Burak et al, 2023;Malhi et al, 2022;Subalusky & Post, 2019).…”

“…Zoogeochemical effects also vary by ecosystem context, where context is determined by variables such as animal density, dominant plant species, underlying soil biophysical properties, and soil biota (Burak et al, 2023;Kristensen et al, 2022;Malhi et al, 2022;Subalusky & Post, 2019;Yang et al, 2008). For example, in forests, the consumptive effects of white-tailed deer (Odocoileus virginianus) can increase net N mineralization rates in high-nutrient conditions and decrease net N mineralization rates in low-nutrient conditions (Popma & Nadelhoffer, 2020).…”