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The Joe Green site harbors a significant
specific natural resource assemblage with many dimensions. It
provides forested habitat for two rare and disappearing plants,
tall bugbane and wayside aster, (See below for details), as well
as the equally rare red-legged frog and pileated woodpecker. The
pileated woodpecker is a vulnerable forest bird that is the primary
maker of nest cavities used later by species such as the Northern
spotted owl. The red-legged frog occupies forested wetlands on
the site characterized by mature Oregon ash, and cottonwood communities
along the SE to NW drainage way. This site has an impressive assortment
of rare biological resources considering the relatively small
overall parcel size.
The site represents a significant portion of the forested headwaters
for the Amazon Creek watershed. The forest assemblage includes
large Oregon oaks with a spreading oak savanna growth form (Oregon
white oak-cow parsnip-candy flower), a mature fir forest stand
(grand fir-Douglas fir-vine maple-hazelnut-sword fern), and ash
forest wetlands (Oregon ash-water parsley- corn lily). Mature
grand fir stands are fairly uncommon at such low elevations and
are indicative of a forest ecosystem tending towards its climax
stage. Oak savanna remnants represent important components of
a globally imperiled plant community. Forested wetlands are not
extensive within this mostly urbanized watershed and are not easily
mitigated elsewhere due to the extended time required to produce
a mature ash forest. Their wetland functions would be difficult
to replace within this portion of the watershed.
The parcel has important proximity and connectivity with other
protected parts of the ridgeline trail system as well as with
nearby populations of rare plants and nearby habitat for the rare
animals already mentioned. It also has hydrological connections
with the lower reaches of the Amazon drainage that includes Amazon
Park and portions south of the park which are being restored and
restructured.
The site is not without some serious infestations of Armenian
blackberry, extensive creeping buttercup, stinky Bob (Robert's
geranium) in the wetlands portions as well as in some otherwise
open areas of the Oak savanna remnant. Human use has produced
some impacts including a deep road and former buried pipeline
route, some stream channel head-ward erosion, some children's
play structures, escaping plants from adjacent landscaped yards
and some indigent camp sites. Despite these disturbance features,
overall the parcel retains impressive natural features and habitats
worth preserving within the Eugene UGB as well as within the Amazon
watershed. With focused, persistent effort, a much larger potential
population of wayside aster and more diverse Oak savanna community
could be restored to this site and the other rare components could
be preserved as valuable urban natural resources.
Significant plants of concern: Aster vialis and Cimicifuga
elata
Aster vialis, wayside aster, is a federal species of
concern and on the Oregon state list as threatened. It is on Oregon
Natural Heritage Program's list one and The Nature Conservancy
ranks it as Globally threatened and threatened in Oregon. Its
historic habitat was probably partly shaded Oak and Oak-Pine savanna.
Its current habitat is regenerating mixed deciduous forest. Its
range is the Western Cascades, Willamette Valley and Columbia
Gorge, but is only reported from Douglas and Lane Counties. In
the greater local region, I am aware of only a few scattered plants
just off the summit trail to Mt. Pisgah, although other sites
occur in the South Hills and McKenzie BLM regions of the Eugene
BLM district. It has not been reported from Springfield. Within
the Eugene Urban Growth Boundary it is known from three other
sites where it is found in numbers under 100 individuals, both
flowering and vegetative at each location. The other locations
are all associated with the ridgeline trail system. The largest
population is on private property where it has been impacted by
development and attempted plant transplantation. The occurrence
on the Greene parcel represents approximately 25% of the known
populations. An undetermined fraction of the existing individuals
occur on the Greene property. The size and extent of suitable
habitat on the Greene property is similar to that of most other
known occurrences in Eugene and the plants status are all declining
due to low reproductive success.
Cimicifuga elata, tall bugbane, is listed as a species
of concern both federally and in Oregon. It is on the Oregon Natural
Heritage Program's list one and is ranked by The Nature Conservancy
as threatened globally and threatened in Oregon. It has a wider
historic and extant range than Aster vialis with occurrences in
13 Oregon counties and distributions in the Coast Range, Willamette
Valley, Western Cascades, Kalamath Mountains, Washington State,
and British Columbia. Its rarity is partly due to extremely restrictive
lower elevation forest habitats associated with moist, shaded,
steep, unstable slopes usually with big leaf maple canopies, rather
open brush under stories, and sword fern ground cover dominance.
It is only occasionally reproductive by seed in its habitat and
does not reproduce clonally.
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Cimicifuga elata
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In the larger local region it is known from sites on private,
BLM and Willamette National Forest lands. It is not known from
Springfield, but occurs at three other known locations along the
ridgeline trail. Each local occurrence is similar in size and
extant to the habitat on the Green parcel. The other three parcels
are protected portions of the Ridgeline Trail (Fox Hollow to Dillard
Road, north slope of Spencer Butte, and Willamette Road to Blanton
Rd. The first city cite is directly up slope from the Greene parcel.
This species is also limited in its reproduction from seed but
only disperses by seed. The western most cite within the urban
growth boundary, for example, has over 100 individual plants,
but only one was found this year with seed capsules on it. No
plants with seeds were observed on the Green parcel in 2005. The
Green parcel contains approximately 25% of known habitat for this
species within the Urban Growth Boundary. •
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Cimicifuga elata habitat on the Green property
Base image: 2000 Orthophoto
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