Part I: from the City of Eugene Stormwater Management Program
from Historical Wetlands of the West Eugene Study Area, April 1988, by
Carol Savonen
Surveyors from 1852-1853 reported many of the prarie flats west of
Eugene were seasonally covered with up to three feet of water.
The majority of the flatter areas below 400 ft elev that have hydric
soils were probably historical wetlands.
Wet praries were plowed , drained, and planted. Others were grazed and
let lie fallow.
Without the benefit of fire, ash, oak and Douglas-fir took
the place of the original prarie. (The Nature Conservancy does controlled
burns periodically to help restore the wetlands.)
Bottomlands were logged. Sloughs and swamps were dredged or filled in.
Creeks were culvertized and channelized and rivers were dammed.
Wet praires were sometime covered 1-3 feet of flood water in the Willow
Creek area between Bailey Hill and Bertelsen Streets and between West
11th and 18th Ave
The old Eugene Airport, near 11th and Danebo, was built on wet prairie
meadow, and is being restored to its original prairie aspect.
etc
For more specific information check the West Eugene Wetland
Self-Guided Tour booklet, Feb 1995, published by BLM, City of
Eugene and The Nature Conservancy. This 24 page booklet is full of
historical information, natural history, and maps as well as checklists of
plants, birds, reptiles, amphibs and mammals.
Part II: From Wetland Plants of Oregon and Washington. 1995. Jennifer Guard. Lone Pine Publishing. $20.p 93-96
Wetland prairies are wet grasslands that developed on clay soil in the Willamette and Umpqua Valleys and the Southern Puget trough. They are dominated by tufted hairgrass and red fescue and maintained by fires from lightning and for the past thousands of years by fires set by Native Americans.
Today only 800 hectares or 0.2% of the 400,000 hectares present in 1850 remain.
After burning ceased in 1855, shrubs and trees invaded and dominated.
Willamette Valley:
In 1850, one third of the Willamette valley was wet prairie (120,000 - 160,000 ha). Today there is 400ha or 0.3% left. There are currently only 6 sites where the wet prairie is beig protected: Finley NWR, Willow Creek, Fern Ridge RNA, Long Tom CEC, Willamette Floodplain RNA and Jackson Frazier Nat Area.
These wetland area are diverse. At Willow Creek over 100 species plants have been identified, with densities as high as 30 species per sq meter. Several species are endemic to the Willamette Valley, ie they occur no where else in the world.
Any comments or suggestions should be sent to jpreed@efn.org