NASA SMD/Earth Science Division

A Study of Biophysical Drivers and Socio-ecological Impacts of Environmental Change in the Yukon-Kuskokwim Delta Region

ABR, in collaboration with the International Arctic Research Center (UAF), Alaska Ecoscience, and the Calista Elders Council, performed inter-disciplinary studies integrating remote-sensing, field-based, and sociological approaches to address environmental change and their socio-ecological impacts in the Yukon-Kuskokwim Delta (Y-K) region of western Alaska. The Y-K is one of the most biologically productive areas of the tundra biome and supports one of the largest indigenous populations in the circumpolar Arctic. Most of the region’s Yup'ik communities are highly reliant on terrestrial subsistence resources, such as the Y-K’s exceptional breeding populations of migratory geese and other waterbirds. The future sustainability of community infrastructure is uncertain due to changing dynamics of climate, coasts, rivers, and permafrost. Notably, large areas of the Y-K lie very near sea-level, and much of the region is underlain by relatively warm permafrost that is highly susceptible to thaw as temperatures warm. Sea-level rise, sea-ice loss, and expected changes in the frequency and intensity of storms make coastal ecosystems and infrastructure especially vulnerable. Specific objectives were to (1) elucidate links between the productivity of Y-K ecosystems and regional-scale atmospheric and cryospheric climate drivers; (2) resolve the spatial extent and drivers of long-term changes in vegetation and physical landscape properties related to landscape-scale disturbance processes; (3) characterize changes in the composition and structure of tundra vegetation across a network of long-term monitoring plots; and (4) relate the observed changes to local observations and concerns regarding environmental change, impacts to ecosystem services, and community sustainability. Work was conducted as part of NASA's Arctic Boreal Vulnerability Experiment (ABoVE) research intiative. Analysis of multi-decadal remote-sensing data time-series, and retrospective studies of historical and contemporary high-resolution imagery provided regional-scale summaries of environmental change and impacts (Task 1). Results of the remote-sensing analysis were used to design and implement a ground-based data collection effort focused on vegetation, soils, hydrology, and permafrost across environmental gradients near two Yup’ik population centers: the central coast region near Chevak (Task 2) and the Yukon Delta near Emmonak (Task 3). Throughout the project, ABR scientists applied findings to address the concerns and needs for information identified by Y-K stakeholders (Task 4) and actively collaborated with other ABoVE research activities and the NASA Science Team (Task 5).