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southeast comer of the park. Recently-planted seedlings consist of ponderosa pine, Oregon <br />white oak, bigleaf maple, and incense-cedar -- all species historically native to the local area. <br />Although there are native shrubs in the riparian forest, there are many non-native trees and <br />shrubs invading that threaten the integrity of this area. Few native shrubs remain along the edges <br />of the savanna-prairie, but some have been sparingly introduced near the existing and newly- <br />planted trees, including snowberry and vine maple. <br />Native herbaceous (non-woody) vegetation persists in very small quantities throughout the park, <br />but has otherwise been displaced by Eurasian species now common throughout this region. <br />Introduced grasses such as tall fescue, Kentucky bluegrass, silver hairgrass, and several bromes, <br />and several introduced clovers dominate the savanna-prairie. Relict populations of native <br />species such as California oatgrass and broadpetal strawberry exist in several small areas of the <br />savanna-prairie, and Douglas' aster and slough sedge are the only native herbaceous plants <br />persisting in significant populations along the river. Small populations of native species such as <br />Cusick's checkermallow and showy milkweed have been introduced in the savanna-prairie areas <br />with the new tree and shrub plantings. <br />Many non-native species present in the park are invasive into native plant. communities and <br />sometimes landscaped areas, and are very difficult to control. In addition to long-established, <br />non-native "lawn weeds" and pasture grasses dominating the savanna-prairie, the following <br />invasive species are present and spreading in the riparian area: sweet cherry, English laurel, <br />Portugal laurel, English ivy, English hawthorn, Scot's broom, English holly, Himalaya <br />blackberry, birdsfoot trefoil, and a new invader, false brome. Yellow flag iris is colonizing along <br />the bank just north of the park. Residual ornamental species in the south portion of the park <br />include invasive weeds (ornamental cherries, Italian arum, etc.), and they contribute little to <br />ecological health of the savanna-prairie habitat. <br />The following table summarizes characteristics of identified vegetation species identified in late <br />winter and spring surveys on the Rasor Park site. Additional species could be identified in <br />surveys conducted throughout the remainder of the growing season. <br />Categories of Rasor Park vegetation (number of species per category). <br />Categar.~` Nafive ~intro fiCnvasl 'Coal <br />Trees 14 6 (2) 20 <br />Shrubs 14 7 (6) 21 <br />Forbs 14 44 (9) 58 <br />Graminoids 11 13 (4) 24 <br />Total 53 70 (18) 123 <br />Note: Intro (Invas) =Introduced species (invasive species). <br />"Invasive" species are a subset of "Introduced" species. <br />Most introduced species are not invasive. <br />Rasor Park Master Plan 8 City of Eugene, Parks Planning <br />