Authors: David Cairns*, Texas A&M University, Rosemary Dwight, Texas A&M University
Topics: Biogeography, Geomorphology
Keywords: Alaska, shrubs, landscape
Session Type: Paper
Start / End Time: 9:55 AM / 11:35 AM
Room: Tyler, Marriott, Mezzanine Level
Presentation File: No File Uploaded
Shrub expansion has been widely documented in the Arctic, however, there are still questions regarding how this process will progress. Regional scale studies show that there is a northward expansion of shrubs, however, owing to local heterogeneity, shrub expansion is not likely to occur at the same rates across all landscapes and regions. Landscape scale factors such as topography, disturbance, and biotic interactions play important roles in regulating shrub expansion. To analyze the relationship between shrub cover and topographic region, as well as the relationship between shrub cover and distance from rivers and streams, eight areas of interest on the North Slope of Alaska were selected. Shrub cover was delineated using a supervised classification method. The topographic regions analyzed included floodplains, river terraces, floodplain slopes, valley slopes, and interfluves. Shrub cover and shrub expansion was analyzed in relation to distance from streams for the whole area of interest, and then repeated for the floodplain only, and all areas outside of the floodplain. We found that shrubs are expanding preferentially in floodplains, on floodplain slopes, and within the first few meters adjacent to streams outside of floodplains. The heterogeneity of shrub cover and expansion shown here is evidence that there are important landscape scale factors that influence shrub establishment and growth.