By: Nick Pankratz, Perri Pond, Jesse Simpson
Background
River View Natural Area (RVNA) is 146-acre forested area located just north of Lewis & Clark’s Undergraduate campus. Up until 2011 this area had been privately owned. During during which it was logged in 1800s and 1950s. Then in July of 2011, this area was acquired by the City of Portland and is now one of the largest single natural area acquisitions in the City’s history. Since the City of Portland’s acquisition of RVNA there has been a huge effort to restore this area to its “natural” state. Thus, beginning in 2011 English Ivy along with other invasive species have been removed. The City of Portland used both chemical as well as physical methods in the removal of ivy. In this lab though we did pay attention ivy presence and ivy removal, we primarily focused on the presence of seven tree species in RVNA. We examined four coniferous species: Douglas fir, Grand fir,Western hemlock, Western redcedar as well as three deciduous species: Bigleaf Maple, Black Cottonwood, and Red alder. Using the mobile app, Fulcrum we counted the quantity of each species at each centroid, the canopy coverage, the presence of ivy as well as other variables. Furthermore, at each centroid we took a photo of something that interested us and subsequently uploaded these to the ENVS220 Flickr album once we got back to the computer lab. Finally, we used ArcMap to map our variables and observe the spatial patterns between the current and 1940s coniferous and deciduous species. Read more…