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Abstract Habitat connectivity is a key factor influencing species range dynamics. Rapid warming in the Arctic is leading to widespread heterogeneous shrub expansion, but impacts of these habitat changes on range dynamics for large herbivores are not well understood. We use the climate–shrub–moose system of northern Alaska as a case study to examine how shrub habitat will respond to predicted future warming, and how these changes may impact habitat connectivity and the distribution of moose (Alces alces). We used a 19 year moose location dataset, a 568 km transect of field shrub sampling, and forecasted warming scenarios with regional downscaling to map current and projected shrub habitat for moose on the North Slope of Alaska. The tall‐shrub habitat for moose exhibited a dendritic spatial configuration correlated with river corridor networks and mean July temperature. Warming scenarios predict that moose habitat will more than double by 2099. Forecasted warming is predicted to increase the spatial cohesion of the habitat network that diminishes effects of fragmentation, which improves overall habitat quality and likely expands the range of moose. These findings demonstrate how climate change may increase habitat connectivity and alter the distributions of shrub herbivores in the Arctic, including creation of novel communities and ecosystems. 

Abstract Beavers are starting to colonize low arctic tundra regions in Alaska and Canada, which has implications for surface water changes and ice-rich permafrost degradation. In this study, we assessed the spatial and temporal dynamics of beaver dam building in relation to surface water dynamics and thermokarst landforms using sub-meter resolution satellite imagery acquired between 2002 and 2019 for two tundra areas in northwestern Alaska. In a 100 km²study area near Kotzebue, the number of dams increased markedly from 2 to 98 between 2002 and 2019. In a 430 km²study area encompassing the entire northern Baldwin Peninsula, the number of dams increased from 94 to 409 between 2010 and 2019, indicating a regional trend. Correlating data on beaver dam numbers with surface water area mapped for 12 individual years between 2002 and 2019 for the Kotzebue study area showed a significant positive correlation (R²= 0.61; p < .003). Beaver-influenced waterbodies accounted for two-thirds of the 8.3% increase in total surface water area in the Kotzebue study area during the 17 year period. Beavers specifically targeted thermokarst landforms in their dam building activities. Flooding of drained thermokarst lake basins accounted for 68% of beaver-influenced surface water increases, damming of lake outlets accounted for 26%, and damming of beaded streams accounted for 6%. Surface water increases resulting from beaver dam building likely exacerbated permafrost degradation in the region, but dam failure also factored into the drainage of several thermokarst lakes in the northern Baldwin Peninsula study region, which could promote local permafrost aggradation in freshly exposed lake sediments. Our findings highlight that beaver-driven ecosystem engineering must be carefully considered when accounting for changes occurring in some permafrost regions, and in particular, regional surface water dynamics in low Arctic and Boreal landscapes.