The Yukon-Kuskokwim Delta (YKD) of Alaska is a source of abundant biodiversity in the Arctic. Branching out from the expanses of the Yukon and Kuskokwim rivers, the YKD is a collection of sediments created by the rivers as they empty into the Bering Sea on the western coast of Alaska. This region is an important migratory bird breeding ground, and one of the most biologically productive land units in the Arctic. Home to over 30,000 Yup’ik people, the YKD is not only ecologically significant, but a source of subsistence-based living, economic productivity, and cultural tradition. Climate change is causing the Circumpolar North to warm three times faster than any other region. Along with increased temperatures, the ice in the Bering Sea continues to disappear, and land-based permafrost continues to thaw. These factors, coupled with the sensitivity of the YKD region, make life in the delta increasingly susceptible to climate change.
Scientists have undertaken new measures to quantify and verify Arctic warming by measuring “greening”. Greenness is a measure of vegetative productivity. While this may sound like a positive ecological indicator, high levels of greenness in a normally snow-covered habitat indicate a dynamic change in habitat, breeding, and animal productivity. Dr. Gerald Frost and a collaborative research team based out of Fairbanks, AK compared spectral and satellite data from multiple governmental research organizations to understand fluctuations in measurements of greenness in the YKD. Researchers analyzed differing greenness measures from satellites and imaging sources. The team compiled data from these multiple sources and verified land vegetative patterns from on-the-ground sources. Ultimately, they were able to determine the overall greenness trends and potential reasons for discrepancies between the various monitoring systems.
The research findings, published in Earth Interactions, indicate that despite high variability due to sea ice, temperature fluctuations, and frequent storms, there has been a steady increase in the greenness of the YKD. The trends presented on the YKD could ring true for other parts of the Arctic experiencing temperature increases. Increases in greenness may change the underlying ecological community and have drastic effects on both the continued biological success of the region and the subsistence-based lives of the Yup’ik people.
Gerald Frost is a senior scientist at Alaska Biological Research, Inc.—Environmental Research & Services in Fairbanks, AK, where he conducts multidisciplinary research on boreal forests and arctic tundra ecosystems with a focus on Alaska and Siberia. His most recent work is focused on vegetation and landscape change detection. He received his PhD from the Department of Environmental Sciences at the University of Virginia
Managing Correspondent: Samantha Tracy
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