New Search
F~<1171tat TVpf 1.DCat1Dn <br />Savanna-prairie Edges, mostly NE and SE <br />Prairie Majority of site <br />Riparian forest Edge of River up to top of bank <br />Vegetation History <br />In 1997, the Oregon Division of State Lands, The Nature Conservancy, and other organizations <br />created a regional vegetation map based largely on field notes from early government surveys. <br />Two vegetation types were mapped in the area that is now Rasor Park: "savanna" was mapped <br />for the majority of the area, and a narrow band of "closed riparian forest" vegetation was mapped <br />along the Willamette River. Large areas to the north and west of the park were mapped as <br />"prairie." The Oregon Natural Heritage Program (Titus et al. 1996) has documented that <br />bottomland forest, savanna and prairie habitat types have become very rare in the Willamette <br />Valley. <br />Savannas, by definition, are areas with widely spaced trees. It is likely, however, based on more <br />detailed analysis of historic vegetation types, that savannas in this region were mosaics of areas <br />with widely-spaced trees (such as Oregon white oak, California black oak, occasional ponderosa <br />pine and Douglas-fir), areas with clusters of these trees, and prairies. These upland prairies (or <br />grasslands) probably were not completely treeless. <br />Aerial photos from the 1930's and 1940's show most of the park was being used for orchards at <br />that time, which may have included nuts (filberts, and possibly walnuts) and fruit. <br />Soils <br />Soils in the study area formed from alluvial deposits on fairly flat floodplains, are deep, and are <br />well to excessively-well drained. <br />Existing Vegetation <br />Current vegetation on the Rasor Park site consists of a riparian forest on the steep bank of the <br />Willamette, and a nearly flat terrace comprising the vast majority of the park, dominated by <br />Eurasian grasses and fortis with scattered trees in portions. (This terrace will be referred to as the <br />savanna-prairie and grassland area in this report.) There are scattered, mature trees, mostly in the <br />northeast and southeast portions, and small native trees have been planted in several areas around <br />the margins. <br />The extreme northeast corner is a grove (or small woodland) of mostly Oregon white oak, with <br />some large Douglas firs near the bike path at the top of the river. Although the oaks in the <br />western part of this area appear to be within park boundaries, they are on a private, vacant <br />residential lot. Several native Douglas-fir and Pacific madrone trees are located to the south of <br />the oaks, extending nearly half way down the eastern section of the site. There also are a few <br />mature. Douglas-fir trees in the southern portions of the western section of the park bordering <br />River Road. Several planted mature, native and non-native trees are present, mostly in the <br />Rasor Park Master Plan 7 City of Eugene, Parks Planning <br />