Climate change, moose, and subsistence harvest in Arctic Alaska

Abstract

Arctic climate is resulting in transformative changes to Arctic social-ecological systems. With warming-induced increases in tall-shrubs, moose are expanding their range northwards. However, the socio-economic implications of this ecological change are unclear. Using field surveys, interviews, and modeling, I assessed the impact of climate change on moose harvest by hunters of Nuiqsut, an Inupiat community in arctic Alaska. Based on a 568 km transect of field sampling on shrubs and herbivore browsing levels, I estimated that the minimum shrub height for moose occurrence was ≥ 81 cm (95% CI: 65 - 96 cm). Patterns of moose geographic distribution mirrored tall-shrub distribution in arctic riparian areas. I also found that snowshoe hares may impact moose habitat via potential resource competition. Habitat suitability models, using Maxent and simpler temperature-threshold models, predicted that moose habitat may more than double by 2099 if current warming trends continue. The model outputs also suggested that climate warming will likely increase habitat connectivity, enhancing range expansion of moose in the Arctic. Finally, I used a coupled social-ecological systems (SES) framework to assess the implications of changes in tall-shrub habitat to moose harvest under future warming. Despite the expected increase in moose habitat and distribution, simulations of an agent-based model showed that the future may not translate into greater harvest opportunities, largely due to the limitation of river navigability for hunters. These findings provide an example in which rapid landscape and resource change may not translate into increased harvest. The integrated assessment with a SES framework revealed new and surprising outcomes, not evident when evaluating social and ecological components separately. This analysis highlighted how a coupled social-ecological framework can be used to assess the effects of climate change on ecosystem services.