AbstractA new occurrence of fossil butternut is recognized based on a permineralized highly scabrate walnut from the middle Miocene of western Washington, USA. The specimen fits the circumscription of Juglans bergomensis (Balsalmo Crivelli) Massalongo, a species that was widespread in Europe and Asia during the Neogene. The occurrence near Brady, Washington, supplements the previously recognized occurrence from Banks Island, Canada, indicating a distribution in mid-latitude western North America as well as Europe and Asia during the Miocene.
Rapid increases in air temperature in Arctic and subarctic regions are driving significant changes to surface waters. These changes and their impacts are not well understood in sensitive high-Arctic ecosystems. This study explores changes in surface water in the high Arctic pond complexes of western Banks Island, Northwest Territories. Landsat imagery (1985–2015) was used to detect sub-pixel trends in surface water. Comparison of higher resolution aerial photographs (1958) and satellite imagery (2014) quantified changes in the size and distribution of waterbodies. Field sampling investigated factors contributing to the observed changes. The impact of expanding lesser snow goose populations and other biotic or abiotic factors on observed changes in surface water were also investigated using an information theoretic model selection approach. Our analyses show that the pond complexes of western Banks Island lost 7.9% of the surface water that existed in 1985. Drying disproportionately impacted smaller sized waterbodies, indicating that climate is the main driver. Model selection showed that intensive occupation by lesser snow geese was associated with more extensive drying and draining of waterbodies and suggests this intensive habitat use may reduce the resilience of pond complexes to climate warming. Changes in surface water are likely altering permafrost, vegetation, and the utility of these areas for animals and local land-users, and should be investigated further.
Landfast Ice Mapping Using MODIS Clear-Sky Composites: Application for the Banks Island Coastline in Beaufort Sea and Comparison with Canadian Ice Service Data
