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���
Chapter ��Chapter ��Chapter ��Chapter ��Chapter ��RESULTSRESULTSRESULTSRESULTSRESULTS
This chapter reports on changes created by
the alternative scenarios described in Chapter 3. In
particular, I examine how the landscape will change
for each future, and how vertebrate terrestrial
species will be affected by these changes. These
are the results that will be used to answer the initial
questions posed:
• can new areas of rural residential develop-
ment be sited without excessive compromise
to the State land use planning ideals?
• does rural cluster development have less
impact on wildlife species than traditional
development?
• is a policy of rural cluster development
coupled with habitat restoration more condu-
cive to preserving biodiversity than current
policies?
Three different types of results are reported
here, based on the alternative futures landscapes.
First, I look at various characteristics of the land-
Restoration burn� oak grove/meadow complex�near Salem� OR� October ����
scape changes, using descriptive metrics that report
the impact of the modeled policies in the context of
the state land use planning system. These results
also estimate the number of houses and people that
would be served by such development.
Next, I compare land use/land cover changes
across the different scenarios. Two spatial extents
are used: the entire basin, and the “impact region,”
a focal area in which the residential overlay zone is
embedded and connected. These results provide
insight into the extent and type of habitat change
that could be expected under the alternative
scenarios.
Finally, I evaluate the effects of the scenarios
on terrestrial vertebrate species through changes in
habitat as expressed in the landscapes. I analyze
the changes in the quality and quantity of habitat
and the impact that these changes may have on
wildlife species within the basin and within the
impact region.
��� RESULTS
Fig� ���� Location of buildable areas� resulting fromthe combination of factors shown in Fig� ���
Selected taxlotsPlanTrend2050 UGBs
1990 UGBs
ValleyecoregionCountyboundaries
Fig� ���� The taxlots of the residential overlayzone� targeted for development�
KEY CHARACTERISTICS OFDEVELOPMENT
In this section, I report results that compare
various metrics pertinent to the debate on new rural
residential development in current resource lands of
the WRB. These metrics address the scale and
location of the development, the extent to which this
development is useful for addressing needs for
housing, and some of the costs relevant to the
current land use policy framework. In particular I
focus on use of farm and forest lands, and on road
development.
Where are the targeted taxlots?
As described earlier in “Methods: Modeling
Rural Development,” there were two major parts to
mapping the residential overlay zone (“ROZ”) in
which new rural residential development was
located. First, suitable building areas were defined,
and second, taxlots containing a subset of these
building sites were selected for development based
on environmental and other criteria described in
Chapter 3. Figure 4.1 shows the building sites;
refer back to Fig. 3.5 to see the components that
formed the criteria for selection. The selection of
buildable soils had the most influence in determin-
ing the location and the amount of potential
development areas. Before the application of the
soils criteria, 1.64 million acres (23% of the WRB
and 51% of the Valley ecoregion) were available
after the other constraints had been applied. With
consideration of soils, this was reduced to a total of
455,738 acres (6% of the WRB), located primarily
along the margin of the Valley in the foothills where
high value farm soils grade into timberlands (Fig.
4.1).
S
N
���
Of the taxlots that encompassed the building
sites, 1,2731 were selected for development,
covering 3.7% of the WRB (5.8% of the Valley
ecoregion) (Fig. 4.2). Figures 4.3(a)-(d) show these
taxlots in context with 1990 RRZs, farm and forest
zoning, natural areas, and travel time to major and
minor UGBs.
Table 4.2 (see page 4-6) lists the number,
total area, and distribution of sizes of the targeted
taxlots by county grouping. Of the taxlot area
(270,812 acres), about one-third or 93,725 acres, is
composed of high value farm/forest soils (as defined
in this project). These are not developable and are
reserved for continued resource use. Thirty-two
percent of the area is buildable (87,623 acres). It is
subdivided into parcels in the RR-5 and RR-15
scenarios, and is the area in which clusters are
located in the RR-CL and RR-CONS scenarios. The
area of lesser resource value that is not used for
development is available for restoration in the RR-
CONS scenario, or continues in resource use in all
other scenarios.
As described earlier, the taxlots are phased
into development over 60 years. Table 4.2 lists the
numbers in each county group that are developed in
each decade.
Because of soils characteristics (as described
in the NRCS SSURGO data base), and because of
the presence of larger taxlots within the southern
half of the valley, Lane, and Benton and Linn
counties have the largest number of taxlots within
the ROZ (Table 4.2).
How many dwellings were sited?
Table 4.2 lists the number of parcels and
clusters within each taxlot for each scenario. Since
the ROZ is held constant in all alternative futures
(excluding PT-EX), and the development footprint
per dwelling varies by scenario, the number of
parcels and hence the number of dwellings varies
by scenario. A house was sited on each of 21,570
parcels under scenario RR-5, and on each of 7,661
parcels under RR-15. For cluster scenarios RR-CL
and RR-CONS, 2,662 clusters were sited with a
total of 17,390 houses. The parcels and clusters
are phased in over the simulation period across
county groups, as shown in Table 4.2.
Despite the 10% density bonus above the
equivalent number of 5-acre parcels for each taxlot,
the cluster scenarios site less houses. Seventy-one
taxlots within the ROZ are undeveloped in the
cluster scenarios because the slopes are too steep
to site the minimum cluster of 3 houses within the
maximum size allowed for a cluster footprint. The
average area per house within a cluster was 1.5
acres; if the encircling firebreak area is included in
the calculation, this area increases to 3 acres per
house. The average number of houses per cluster
is 6.5 (Table 4.2).
WRB
Clackamas, Multnomah, Washington Marion, Polk Benton, Linn Lane
Rural Residential Zones, 1990
area (acres) 228,979 120,896 29,370 25,927 52,787
number of houses 38,604
avg area per house (acres) 5.9
Rural Residential Zones, 2050
area (acres) (1) 203,501 99,081 27,675 25,522 51,224
number of houses 43,459
avg area per house (acres) 4.7 (1) reduced in size due to annexation by 2050 of some rural residential zones into expanded ugbs
Counties Table ���� Statistics describing ��and ��� Rural Residential Zones�The changes within the RRZs in��� are common to all scenarios�
LANDSCAPE PROPERTIES � how many dwellings were sited?
��� RESULTS
SNF
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� T
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LANDSCAPE PROPERTIES � how many dwellings were sited?
Fig
� �
�� (
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��� RESULTS
Table ���� Statistics describing taxlots targeted for development� and the resulting development sites�
WRB
Clackamas, Multnomah, Washington Marion, Polk Benton, Linn Lane
Taxlots targeted for development
number of taxlots 1,273 225 158 493 397
developed in 2010 169 34 22 65 48
developed in 2020 267 50 35 103 79
developed in 2030 285 50 36 103 96
developed in 2040 315 44 37 128 106
developed in 2050 237 47 28 94 68
taxlot size
median (acres) 155 131 142 160 169
10-%ile (acres) 77 72 78 78 80
90-%ile (acres) 409 336 309 468 470
area (acres) 270,812 45,292 25,868 108,918 90,734
reserved resource area (acres) 93,725 17,848 8,057 34,103 33,717
potential building area (acres) 87,623 16,352 8,920 35,182 27,168
potential restoration area (acres) (1) 177,087 27,444 17,811 74,815 57,017
5-acre parcel scenario
number of parcels 21,570 3,856 2,121 8,736 6,857
built in 2010 1,796 298 180 785 533
built in 2020 3,721 647 397 1,485 1,192
built in 2030 4,345 796 441 1,742 1,366
built in 2040 5,228 947 545 2,112 1,624
built in 2050 6,480 1,168 558 2,612 2,142
area (acres) 112,962
avg area per house (acres) 5.2
15-acre parcel scenario
number of parcels 7,661 1,325 752 3,152 2,432
built in 2010 632 109 74 278 171
built in 2020 1,322 244 137 506 435
built in 2030 1,525 268 159 614 484
built in 2040 1,933 332 195 813 593
built in 2050 2,249 372 187 941 749
area (acres) 124,578
avg area per house 16.3
Cluster scenarios
number of taxlots with clusters 1,202
number of clusters 2,662
number of houses 17,390 3,084 1,894 6,858 5,554
built in 2010 1,442 221 166 605 450
built in 2020 3,006 478 343 1,265 920
built in 2030 3,460 587 422 1,369 1,082
built in 2040 4,363 910 448 1,743 1,262
built in 2050 5,119 888 515 1,876 1,840
area (acres)
inside firebreaks 25,850
including firebreaks 52,789
avg cluster area (acres)
inside firebreaks 9.7
including firebreaks 19.8
avg area per house (acres)
inside firebreaks 1.5
including firebreaks 3.0
avg. number of houses per cluster 6.5 (1) includes buildable sites, but excludes high value farm soils and forest site class I and II
Counties
���
For comparison purposes, Table 4.1 shows
statistics for rural residential zones. These RRZs
covered 228,979 acres in 1990, and were reduced
to 203,501 acres by 2050 because of absorption of
RRZs into expanding UGBs, particularly in the
Metro/Portland area. In 2050, these RRZs occupy
about 180% as much area as that covered by the
parcels within the RR-5 scenario (112,962 acres),
and about 165% of that covered by RR-15 parcels
(124,578 acres). The density of the RRZs is similar
to that of 5 acre subdivision. Note also that it is
estimated that there are only 38,604 houses in the
RRZs in 1990, out of a mapped total of 117,691
rural houses. The remainder are scattered through-
out the rural farm and forest areas.
How does the rural population
change?
In 1990, it is estimated that about 283,840
people or 14.2% of the population in the WRB lived
in rural areas, outside UGBs (Payne, 2002b).
Under all future scenarios of this project, urban
areas are densified according to comprehensive
plans and legislative intent; new urban housing
averages 7.9 dwelling units/acre (gross density),
almost twice the average density in 1990 (4.2
dwelling units/acre). Under the plan trend scenario,
PT-EX, the rural population in 2050 grows to
approximately 284,080 while the proportion falls to
7.3% of the WRB population. Under the most
expansive of the alternative futures, RR-5, the rural
population is estimated to be 334,530 or 8.6% of
the WRB population in 2050 (Table 4.3).
How many more roads are needed?
Due to increased rural traffic in all future
scenarios due to population growth, parts of the
road network throughout the basin will need to be
upgraded. I did not attempt to evaluate the magni-
tude of this need, but instead focused on roads only
within the ROZ and the connection of the taxlots to
the existing road network.
Figure 4.4 and Table 4.4 compare the length of
roads that provide access to the new development
areas within the ROZ. Since the 1990 data do not
show roads serving all rural houses within the WRB,
it is likely that the measured lengths are underesti-
mates of the true road network. And, since the road
modeling was calibrated based on the data shown
in the 1990 mapping, it is similarly likely that the
modeled lengths are underestimated. Nevertheless,
the comparison between scenarios is useful for a
magnitude estimate.
In 1990, within the targeted taxlots of the ROZ
and prior to any development, there were approxi-
mately 606 miles of roads, most classed as “local”
or “other” roads, i.e., small roads with low traffic
volume. Many of these are likely to have been
logging roads which would require upgrading for
residential access. Only 5 to 8 miles of new roads
%rural
1990 14.2
2050 scenarios
Plan Trend 7.3
5-acre parcels 8.6
15-acre parcels 7.7
Clusters 8.3
Rural Pop.
278,770
284,080
334,530
302,110
325,010
Table ���� Estimated rural population and thepercent of total basin population for each scenario�
0
200
400
600
800
1000
1200
1400
1600
1800
2000
Within RRZs, 1990
5-acre parcels
15-acre parcels
clusters
Roa
d le
ngth
, mile
s
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5R
oad
dens
ity, m
i/sq.
mi.
1990 2050 Density
Fig� ���� Length of roads within taxlots of the ROZunder different scenarios and within �� RRZs�Density is measured within the developed areas ofthe ROZ in ����
LANDSCAPE PROPERTIES � how does the rural population change?
�� RESULTS
Table ���� Statistics comparing length and density of roads within rural developments
outside the targeted taxlots were needed to connect
the taxlots to the existing extensive road network
(Table 4.4). The cluster scenarios required 490
miles of new roads within the ROZ to service the
houses, compared with 654 miles in the RR-15
scenario and 1046 miles in the RR-5 scenario. In
the latter, the total road length was very similar to
that found in the 1990 RRZs.
Road density was initially low at 1.4 miles/ sq.
mi. within the targeted taxlots. By 2050, the density
rose to a maximum of 3.9 mi./sq.mi. within the ROZ
and 4.8 mi./sq.mi. within the developed portion of
the ROZ under scenario RR-5. The other scenarios
showed lower road densities (Table 4.4).
What losses of high value farmland
occurred?
Within the WRB, there are about 1,940,773
acres of high value farm soils ((as defined in OAR
660-033-0020(1)(a)(A), OAR 660-033-
0020(8)(a)(A)(B)) in private ownership (Table 4.5)
(67% of all private lands). A significant portion of
this area (37%) is potentially developable under the
criteria specified in this project (excluding the
policies of resource soil protection, and taxlot
properties). However, under the scenario rules, the
targeted taxlots of the ROZ contain only 51,222
acres (2.6%) of high value farm soils. In the sce-
narios, most of these areas (if sufficiently large for
viable farm use) are retained as farmland under the
assumption that resource use is mandated. Prece-
dent exists in the statutes for the prevention of
nuisance complaints from rural homeowners living
near farms.
The developed parcels contain only a very
small amount of these soils. Under the RR-5
scenario, 4,849 acres of high value farm soils are
located within the 5-acre parcels subdivided from
the targeted taxlots of the ROZ. Under, the RR-15
Fig� ��� Comparison of use of high value farm soilsin �� with ��� for the RR�� scenario� “Otherdeveloped” refers to non�agricultural use outsidethe ROZ taxlots� Red refers to the ROZ�
developed
25%
undeveloped75%
1990
26%
resource use 2.2%
other developed
developed0.4%
72%undeveloped
2050
1990Total Length
(miles) (1)Road Density
(mi/sq.mi)Arterials Major
collectorsMinor
collectors
Within RRZs 1649 4.6 149 242 134 903 221
WIthin targeted taxlots 606 1.4 11 32 35 237 291
2050 (2)
New roads inside targeted taxlots (miles)
New roads, outside targeted taxlots (miles)
(3)
Total Length (new +
existing) (miles)
Average over all targeted
taxlots
Within developing areas only
Estimated Area of new
roads (acres) (5)
Within targeted taxlots --
5-acre parcels 1046 6 1658 3.9 4.8 5,072
15-acre parcels 654 5 1265 3.0 3.4 3,171
Clusters, incl firebreaks 490 8 (4) 1086 2.7 2.9 2,376
(2) New roads were not added to 1990 RRZs in scenario modeling for 2050.(3) These are road segments that join roads within targeted taxlots to existing road system(4) 2.5 miles of road are constructed through "targeted taxlots" that are not developed in the cluster scenarios(5) Assuming 40 ft wide.
Approximate Length of Road by Road Class (miles)
Road Density in targeted taxlots (mi/sq.mi)
(1) This is the length of roads mapped by ODOT (1997). Other roads may exist.
Local roads Other
��
scenario, there are 7,885 acres of high value farm
soils within the parcels, compared with 2,064 acres
in the cluster footprints. These areas constitute less
than 0.4% of the total acreage of high value farm
soils in private ownership. Thus, the withdrawal of
farmland from resource use is very small. Further, it
is assumed that within the 15 acre parcels some
small-scale hobby or specialty farms would be
established.
Table 4.5 and Fig. 4.5 compare the impact on
the inventory of farm soils of development through
1990 with subsequent proposed development.
More than 25% of high value farm soils lie within
1990 UGBs, RRZs, and within 100 ft. of rural
structures — areas no longer supporting farm use.
Thus, under the rules of the alternative scenarios of
this project (excluding PT-EX), the constrained rural
development affects a disproportionately small
percent of the high value soils.
What losses of high productivity
forests occurred?
As discussed previously, there are no legal
definitions in the Oregon statutes that define “high
value timberlands.” Table 4.6 presents statistics for
each forest site class describing the area impacted
by development. Over 2.39 million acres of the
WRB in private ownership (82% of all private lands)
have soils that are classified for timber production.
Fifty percent of this area is potentially developable
under the criteria specified in this project (excluding
the policies of resource soil protection and taxlot
properties). However, under the scenario rules, the
targeted taxlots of the ROZ contain only 7.6% or
180,990 acres of forest soils. From 57% to 80% of
this area (depending on the scenario) is retained in
resource use as development is restricted to only a
portion of the taxlots. Precedent exists within the
statutes to ensure that forestry can continue in the
neighborhood of new dwellings.
As shown in Table 4.6, the area subdivided
into 5-acre parcels in the RR-5 scenario contains
72,693 acres of forest soils or 3% of the inventory of
forest soils under private ownership. The 15-acre
parcels of RR-15 scenario contain 78,199 acres,
some of which are likely to be managed by the
landowners for small woodlots. The compact
developed areas of the cluster scenarios contain
only 34,208 acres or 1.4% of forest soils.
Table 4.6 and Fig. 4.6 compare the impact of
development through 1990 with new development in
2050 under the alternative futures. About 11% of
site class I-IV forest soils lie within 1990 UGBs,
RRZs or within 100 ft. of 1990 rural structures. The
areas of development within the ROZ use less than
3.2%.
What is the zoning of the targeted
taxlots?
While the zoning of each taxlot is not known, a
generalized zoning map of the WRB (Fig. 4.3b)
acres %
High Value Farm Soils in Private Ownership 1,940,773 100%
Area of suitable building sites (excluding consideration of resource soils and taxlot properties) 715,168 37%
Impacted Soils from urbanization
WIthin 1990 UGBs 269,791 13.9%
Within 1990 RRZs 136,625 7.0%
WIthin 100 ft of structures outside RRZs, 1990 88,192 4.5%
Total1990 Impacted area (1) 494,608 26.0%
Total 2050 Impacted area under Plan Trend (2) 511,819 26.4%
Within targeted taxlots 51,222 2.6%
Within area of land use change in targeted taxlots
5-acre parcels 4,849 0.2%
15-acre parcels 7,885 0.4%
clusters, incl. firebreak (3) 2,064 0.1%
restoration (3) 529 0.0%
(1) conservative estimate of impact -- roads not included
(2) UGB expansion area in 2050 added to 1990 impacted area
(3) ideally, all high value soils are retained for resource use; the areas intersected here are in the firebreak and restoration areas and arise in taxlots with insufficient high value resource areas for viable management. These high value areas transition to a vegetated land cover only.
Table ��� Statistics describing the status of highvalue farm soils within the WRB and changes dueto development under different scenarios�
LANDSCAPE PROPERTIES � what losses of high productivity forests occurred?
���� RESULTS
Forest Site Class I II III IV V TotalProductivity (cu.m/ha/yr) ≥ 15 12-14 9-11 7-8 4-6Productivity (cu.ft/acre/yr) ≥ 215 165-224 120-164 86-119 50-85
Private ownership (acres) 26,743 1,298,477 950,922 109,343 8,709 2,394,194
Area of suitable building sites (excluding consideration of resource soils and taxlot properties) 13,404 724,118 437,559 33,641 5,091 1,213,813
Impacted Soils from urbanization
Within 1990 UGBs 1,361 78,486 25,544 34 - 105,425
Within 1990 RRZs 4,181 64,639 51,805 1,004 159 121,788
Within 100 ft of structure outside RRZs, 1990 1,668 19,870 19,149 576 80 41,343
Total 1990 Impacted area (1) 7,210 162,995 96,498 1,614 239 268,556
% of site class impacted, 1990 27.0% 12.6% 10.1% 1.5% 2.7% 11.2%
Total 2050 Impacted area under Plan Trend (2) 8,640 166,684 101,063 1,634 239 278,260
% of site class impacted, 2050 32.3% 12.8% 10.6% 1.5% 2.7% 11.6%
Within targeted taxlotsArea of site class 399 62,920 104,448 11,788 1,435 180,990 % of site class within targeted taxlots 1.5% 4.8% 11.0% 10.8% 16.5% 7.6%
Within area of land use change in targeted taxlots
5-acre parcels 21 4,676 58,555 8,196 1,245 72,693
% of site class within 5-acre parcels 0.1% 0.4% 6.2% 7.5% 14.3% 3.0%
15-acre parcels 25 7,483 61,268 8,221 1,202 78,199
% of site class within 15-acre parcels 0.1% 0.6% 6.4% 7.5% 13.8% 3.3%clusters, incl. firebreak (3) 5 1,793 28,265 4,139 5 34,208
% of site class within clusters 0.0% 0.1% 3.0% 3.8% 0.1% 1.4%restoration area (3) - 1,563 37,689 4,660 624 44,537
% of site class within restoration area 0.0% 0.1% 4.0% 4.3% 7.2% 1.9%
(1) conservative estimate of impact -- roads not included
(2) UGB expansion area in 2050 added to 1990 impacted area
Area of Site Class (acres)
(3) ideally, all site class I and II areas are retained for resource use; the areas intersected here are in the firebreak and restoration areas and arise in taxlots with insufficient high value resource areas for viable management. These high value areas transition to a vegetated land cover only.
Timberland (private ownership)
Table ���� Statistics describing the status of timberlands within the WRB and changes due todevelopment under different scenarios�
Fig� ���� Comparison of use of forest siteclass I�IV soils in �� with ��� for the RR�� scenario� “Other developed” refers to non�forest use outside the ROZ taxlots� Redrefers to the ROZ�
developed11%
undeveloped89%
other developed
12%
undeveloped81%
developed3%
resource use 4%
1990 2050
����
indicates that 60% of the taxlot area is zoned
“primary forest”, 6% “impacted/secondary forest”,
24% “exclusive farm use”, and 8% “farm/forest”.
Thirty-eight percent of the taxlots (483), covering
50% of the ROZ, were in private industrial forest
ownership.
KEY CHANGES IN LAND USE/LANDCOVER AND HABITAT
In this section, the landscapes of the five
alternative future scenarios are compared and
contrasted for changes relative to 1990 in the major
LU/LC categories: closed conifer (to assess the
effects of forestry), agriculture, urban, and natural
vegetation. These comparisons can reveal trends
that affect habitat conditions and thus wildlife. In
the next section, the species response to these
changes will be discussed.
Because the alternative futures RR-5, RR-15,
RR-CL and RR-CONS differ only within the rela-
tively small area of the ROZ (3.7% of the WRB), the
most visible trajectories of change over the entire
WRB are caused by the PT-EX policies expressed
in the forest and agricultural lands of the basin.
However, some wildlife species are potentially
sensitive to changes in LU/LC within the ROZ if they
have a limited range or scarce habitats that lie
within the ROZ. I thus examine the LU/LC trends at
two scales: that of the basin, and that of a focal
area connecting and encompassing the taxlots of
the ROZ. I refer to this area as the “impact region”
(see Fig. 4.12).
How is habitat expected to change
under current policies?
The changes from 1990 to 2050 under the PT-
EX scenario describe landscape conditions that are
likely to occur if current policies are maintained.
This is the landscape where no new rural residential
areas or habitat reserves are established. Figures
4.7(a) and 4.8(a) (see pages 4-12 and 4-13,
overleaf) map 1990 and 2050 plan trend conditions
in terms of land use/land cover; Figs. 4.7(b) and
4.8(b) show the corresponding habitat conditions for
1990 and 2050, respectively. See Appendix A.7 for
tabulations of the area of each habitat in the WRB
by scenario. Fig. 4.9 compares the composition of
the WRB in terms of habitat in 1990, 1850, and in
2050 under PT-EX scenario.
Closed conifer forest
1. The area of conifer forests increases;
2. The age of conifer forests decreases, andold growth areas are reduced.
A shift in the age distribution of closed conifer
forests occurs over the 60-year simulation period
(Fig. 4.10). Trees in the reserves mandated by the
Northwest Forest Plan remain in the oldest age
class while private industrial forests get younger.
Also, conifers are being added through succession.
The net effect is that the average age falls by about
12 years: from around 70 years to around 58 years
(assuming an even distribution of age within each
conifer age group).
Fig� ��� Comparison of habitat classes in theWRB in �� with PT�EX ���� and with � ��
0%
20%
40%
60%
80%
100%
Are
a as
% o
f WR
B
Developed 8%Agricultural habitats 18%Seasonal wetlands 0%Upland prairie 0%Oak Savanna 0%Shrubs 5%Hardwood forests 7%Mixed forests 23%Conifers > 80 yrs 20%Conifers 0-80 yrs 17%
19909% 0%17% 0%0% 4%0% 10%0% 7%4% 7%7% 3%18% 2%16% 58%26% 0%
plan trend 1850
LU/LC AND HABITAT CHANGES � How is habitat expected to change under current policies?
���� RESULTS
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LU/LC AND HABITAT CHANGES � How is habitat expected to change under current policies?
200
20
Mile
s
���� RESULTS
1,000,000
2,000,000
3,000,000
1990 LU/LC categories converting to conifer forests in 2050
Are
a of
Clo
sed
Con
ifer
For
est (
acre
s)
2050 3,142,674
1990 2,725,447
TOTALmixed
forests
hardwd
forestsdry
shrubconifers other
2,713,421 376,735 27,475 14,611 10,433
0
Fig� ����� Area of closed conifer forests in PlanTrend scenario� PT�EX� compared with area in��� Bars to right show area gained by successionfrom other land covers� “Other” includes� indecreasing order of contributing area: grass/tall�bare� tree/open upland� wet shrub� grass/natural�
The amount of conifer forest increases over
the period of the simulation as some areas of
unmanaged mixed and hardwood forests, shrub and
open areas succeed to conifer cover (Table 4.7, Fig.
4.11). In 1990, 2.73 million acres of closed canopy
conifer forests were present in the WRB. Under the
PT-EX scenario, it is estimated this will increase to
3.14 million acres by 2050 (Fig. 4.11), despite a loss
of 12,206 acres to development (expanding UGBs,
upgrade of roads, densification of RRZs).
The area of old growth conifers (older than 80
years) decreases from 20% of the basin to 16%, a
drop of 284,200 acres. In 1850, it was estimated
that this habitat covered 58% of the WRB. (Fig. 4.9).
(Appendix A.6 shows the 1850 landscape).
0%
20%
40%
60%
80%
100%
Conifer 0
-20 yrs
Conifer c
losed 21-40
Conifer c
losed 41-60
Conifer c
losed 61-80
Conifer c
losed 81-200
Conifer c
losed 200+
% o
f con
ifers
1990 2050 2050(a)
Fig� ����� Age distribution of conifers under PlanTrend Scenario� PT�EX� expressed as percent ofconifers as old or older than each age category�Red: ��� conifers were present also in ��;Green: includes conifers gained by succession�
1990, Habitatconifer forest
mixed forest
hardwood forest
% of 1990 area
% of 1990 area
conifer forest - - - - 0 429,197 16% 12,267 0% 15%
mixed forest 376,735 - - - 376,735 (352,383) -21% 14,957 -1% -22%
hardwood forest 27,475 21,743 - - 49,218 (15,268) -3% 12,824 -2% -5%
shrub 17,451 925 23,942 - 42,318 (31,617) -9% 26,221 -8% -17%
grass/natural 373 20 820 814 2,026 (2,026) -9% 2,060 -9% -19%
seasonal wetlands - - 1,471 916 2,387 (2,387) -9% 254 -1% -10%
agricultural 7,164 1,664 7,716 8,971 25,515 (25,515) -2% 62,194 -5% -7%
(1) Acres of 2050 habitat gained through succession 429,197 24,352 33,949 10,701
Change in 1990 area
from development
and succession
(2) Acres lost from 1990 habitat by
succession
Net change (1) - (2)2050, Habitat increased by succession 2050, Habitat lost to
development
shrub Acres Acres
Table ���� Habitat areas gained and lost through vegetative succession� compared with areas lost due todevelopment� PT�EX scenario� ���� For example� ����� acres of hardwood forest convert to conifer� and������ acres to mixed forest� The net loss in hardwood forests is ���� acres� or �� of the area present in��� This contrasts with ��� �� acres lost to development� The total change in area since �� is ��
���
Urbanization
1. UGBs expand by only 12% (51,000 acres)despite a doubling of the urban population;
2. Developed areas occupy 9% of the basin by2050, an increase of 1% from 1990.
In 1990, there are 444,000 acres within UGBs.
Following current land use policy, UGB expansion
from 1990 to 2050 is minimized by increasing urban
residential densities: 51,000 acres (12% of area
inside 1990 UGBs) are added. 12,382 new rural
structures are added within RRZs.
The net increase in built habitat is 24% or
102,840 acres. Of this, 82,671 acres are developed
within the 2050 UGBs. This includes part of the
1990 “buildable lands inventory” and rural areas
incorporated into the UGBs through boundary
expansion. The rest of the new built habitat is
created by new rural home construction, and also by
landscape nursery expansion (considered to be
“built low density” habitat because of land manage-
ment practices).
With the upgrade of minor collectors to handle
the increased traffic caused by population growth,
an additional 20,000 acres of new road surface area
are created.
Agriculture
1. About 4.7%% (62,194 acres) of 1990agricultural crop area is lost to development;
2. About 1.9% (25,515 acres) of 1990 agricul-tural areas convert to woody vegetation throughsuccession.
In 1990, there are 1.32 million acres of
agricultural habitats within the WRB. Of this area,
only 62,194 acres are removed from production
from 1990 to 2050 because of development, a loss
of 4.7%. This reflects the emphasis on the preserva-
tion of farmland under current land use policies. In
unmanaged areas with agricultural land cover
(predominately pasture), about 25,515 acres
convert through succession over 60 years to shrub
(8,971 acres), conifers (7,164 acres), hardwood
forest (7,716 acres; primarily ash), or mixed forest
(1,664 acres) (Table 4.7).
The relative proportions of the agricultural
habitats in 2050 remain about the same as in 1990
with the exception of “leafy vegetables” and “grass/
tall”. The former falls from about 9% of the total
agricultural habitat area to about 6%, and the latter
rises from about 77% to 80%, mainly due to the
conversion of irrigated annuals and perennial crops
to grass seed. This proportional shift occurs even as
the area of “grass/tall” habitat falls to 994,813 acres.
Other crops to suffer relatively large acreage losses
(in comparison with their 1990 status) are berries/
vineyards (loss of 7,169 acres or 42%) and leafy
vegetables (loss of 72,698 acres or 40%).
Natural Vegetation
1. 68,600 acres of natural vegetation aredeveloped;
2. Scarce seasonal wetlands and uplandprairie habitats continue to decline; oak savanna isabsent.
3. The trend is to increasing dominance byyoung conifers and less representation of earlysuccessional communities, and those that dependon disturbance for persistence.
“Natural vegetation” (all forest classes, shrub,
native grasslands, seasonal wetlands) comprises
habitat that is most likely to contain native plants,
although often with exotic components. Two
processes affect the amount present in any of the
alternative futures. The first is development; the
second is vegetative succession. As described
earlier in “Methods,” succession only occurs in
unmanaged areas of the landscape. Thus, in areas
of active forest or farmland use, succession is not
modeled: in these areas land cover types can
convert from one category to another but only within
the set of conifer age groups or agricultural crops,
respectively, as land use practices dictate.
Consider first the area within the WRB in
which the succession model operates — the so-
LU/LC AND HABITAT CHANGES � how is habitat expected to change under current policies?
���� RESULTS
called “unmanaged” lands (see Fig. 3.8). This area
is 32% of the valley ecoregion and 45% of the
basin. I found this to be a surprisingly large amount
given that the Willamette Basin is a productive
resource area in intensive management. The
mapped areas within the valley ecoregion are
primarily in the foothills and in areas with high
density of smaller parcels, particularly as seen in
the northern part of the valley. Natural vegetation
occupies 89% of this region.
Table 4.7 lists groupings of the various
habitats and shows area gained or lost due to
modeled vegetative succession from 1990 to 2050.
While the results appear conservative it is difficult to
know whether they are realistic. As discussed
earlier, deriving parameters for a basin-wide
successional model is very difficult: the process is
highly site specific and can be altered by human
intervention. The model must be viewed with
caution. Nevertheless, the trends appear to be
reasonable, and as such, allow the scenario to
include the recognized long term trends of continu-
ing loss of hardwoods, shrub, and native grasslands
in areas not under active management.
Using the amount of habitat present in 1850 as
a yardstick (Fig. 4.9), the rare habitats in 1990 and
2050 are upland prairie (“grass/natural”), wet prairie
(“seasonal wetlands”), “oak savanna,” (all less than
10% of 1850 levels) and to a lesser degree, “conifer
>80 years”. In this context, the net loss of 19% of
“grass/natural” and 10% of “seasonal wetlands,” as
shown in Table 4.7, is large. On the other end of the
scale, the much larger percentage loss of mixed
forest habitats (22%) is small when compared to the
very large inventory of these habitats in 1990 and
2050 in relation to 1850 conditions (8 to 10 times as
much). “Oak savanna” is nonexistent in 1990 and in
2050 PT-EX landscape. The net loss in hardwood
forest habitats reduces the options to restore oak
savanna under active conservation management.
It is in consideration of the fate of these “rare”
habitats, that the horns of the dilemma are revealed.
Over 70% of the natural grass and shrub habitats,
and 66% of hardwood forests are concentrated
within the “unmanaged” area. Without disturbance,
these habitats will slowly diminish. The remainder is
found primarily in agricultural areas. Here, the type
of active management conducted by these owners
can have a large impact on the amount of habitat
retained over time.
How is habitat expected to change
under the alternative futures?
The differences between all the alternativefutures (excluding PT-EX) are confined (by scenario
design) to the ROZ (3.7% of the WRB). However,
due to adjacency considerations (see “Methods”),
some changes outside the ROZ can affect habitat
within. And while connectivity is not considered by
the habitat evaluation model used in this project, the
landscape matrix linking patches of habitats can
affect the viability of wildlife populations. Thus, I
chose to assess the habitat changes expressed in
the alternative futures within an “impact region” in
which the ROZ is embedded (Fig. 4.12). Within this
region, which covers 12% of the WRB, the 5-acre
parcels of the RR-5 scenario occupy 12.5%; the
parcels of the RR-15 scenario, 13.7%; the clusters
of the RR-CL scenario, 5.8%; and the clusters and
S
N
Fig� ����� Map of “impact region” (black) overlainwith the taxlots of the ROZ (grey)� Inset is anexpansion of the area indicated� The impactregion both encompasses and connects thetaxlots of the ROZ�
����
restoration area of RR-CONS scenario, 15.2%.
Appendix A.8 tabulates the area of each habitat in
the impact region for all scenarios. Comparison of
Fig. 4.13 with Fig. 4.9 shows the differences in the
composition of the habitats in the impact region
versus the WRB. Further, Appendices A.9 and A.10
compare, for all future scenarios, the change in the
area of each habitat with respect to its 1990 area in
the WRB, and in the impact region, respectively.
Closed conifer forest
Within the impact region:
1. The percentage of conifers in 1990 is aboutthe same as in the WRB, but there is less oldgrowth.
2. Area of conifers increases in all futurescenarios to occupy 35-40% of the region, withhighest amount in PT-EX and least amount in RR-CONS.
3. Conifer forests areyounger on average than thosein the WRB as a whole; theaverage age decreases by 21years to about 51 years over allalternative futures.
4. In 2050, the extent ofconifer forests is close to that of1850, but old growth treesoccupy only 17-20% of theirhistorical area.
Fig. 4.14 compares the
area of closed conifer habitats
for each future scenario and
1990. The trends are very
similar in all futures, with
increasing emphasis on younger
trees in 2050.
Greater frequency of
logging in the alternative futures
reduces the total conifer
acreage with respect to PT-EX.
In the RR scenarios there are at least two occasions
in which logging of marketable trees (older than 40
years old) occurs: first, under resource management
(as in PT-EX), and second, when taxlots are
selected for development and site preparation
0%
20 %
40 %
60 %
80 %
100 %
Are
a as
% o
f Im
pact
Reg
ion
Developed 4%Agricultural habitats 19%Seasonal wetlands 0%Upland prairie 1%Oak Savanna 0%Shrub 8%Hardwood forests 8%Mixed forests 25%Conifers > 80 yrs 14%Conifers 0-80 yrs 20%
1990 5-acre parcels
15-acre parcels clusters conserv.
clusters 1850plan trend
6% 10% 7% 8% 8% 0%18% 18% 20% 20% 19% 0%0% 0% 0% 0% 1% 5%0% 0% 0% 0% 2% 16%0% 0% 0% 0% 3% 15%7% 8% 8% 7% 6% 9%8% 7% 7% 7% 7% 3%21% 18% 18% 19% 18% 5%8% 7% 7% 7% 7% 41%32% 31% 31% 30% 28% 0%
Fig� ����� Composition of habitat in the impact region for allscenarios� All the selected taxlots constituting the ROZ areembedded in this impact region (see text)�
50
100
150
200
250
300
350
400
Are
a (t
ho
usa
nd
s o
f ac
res)
Con
ifer
0-20
yrs
Con
ifer
clos
ed21
-40
yrs
Con
ifer
clos
ed41
-60
yrs
Con
ifer
clos
ed61
-80
yrs
Con
ifer
clos
ed81
-200
yrs
Con
ifer
clos
ed20
0+ y
rs Tot
al
1990
plan trend
5-acre parcels
15-acre parcels
clusters
conserv.clusters
34%
40%
Fig ����� Comparison of the distribution of areaof closed conifer habitats for all alternativefutures� and �� within the impact region�
LU/LC AND HABITAT CHANGES � How is habitat expected to change under the alternative futures?
��� RESULTS
occurs. All trees regardless of age are removed
from the firebreak area around houses and clusters,
and, with houses generally isolated and spaced
apart from each other, RR-5 loses the greatest area
of trees. Under RR-CONS, while some conifers are
removed to make way for restoration of other
habitats, others are retained for restoration to old-
growth stage. Under RR-15, the owner of the parcel
can log the property once the remaining and
reseeded conifers reach marketable age, with the
result that this future has the least area of market-
able trees by 2050.
Urbanization
1. Urbanized habitats rise from 4% in 1990 tooccupy from 6% (PT-EX) to 10% (RR-5) of theimpact region, a result comparable to the proportionin the WRB as a whole;
2. Of the RR scenarios, the developedfootprint is greatest under RR-5, and least underRR-15;
3. Clustered housing is least costly in terms ofdeveloped habitat per new house. 15 acre subdivi-sion is the most expensive.
Residential development within the impact
area occurs within 1990 RRZs as well as within the
ROZ. By 2050, over 33,500 acres of “built low
density” habitat are found in this region of the PT-
EX landscape. This more than doubles to 71,700
acres in RR-5, the most expansive of all alternative
futures. Although other development occurs to
support the small-scale farming and logging
activities in the RR-15 scenario, this future land-
scape has the least increase in urbanized area due
to the lower number of houses sited. However, if
the increase in built habitat per new house is
computed, cluster development is the most efficient
with 1.5 acres per new dwelling, versus 1.8 acres/
house for 5-acre parcels, and 2.1 acres/house for
15-acre parcels. The latter are most expensive due
to the isolation of each house — there is much less
possibility of “sharing” the 2 acre zone of influence
around the house with an adjacent house than there
is in either the RR-5 or cluster scenarios.
Upgrading roads outside the ROZ by widening
to accommodate additional traffic adds an additional
3,500 acres of development to all alternative
futures. Further, it is estimated that from 2,375
acres (RR-CL and RR-CONS) to over 5,000 acres
(RR-5) of habitat are further degraded by the
presence of the new roads within the ROZ (Table
4.4). Adding the roads to the built habitat, the cost,
expressed now as overall developed habitat per
new house, rises to 1.6 acres for clusters, 2.0 acres
for 5-acre parcels, and 2.5 acres for 15-acre
parcels. For RR-15 sites, the cost per house of road
access (in terms of acres of roads/house) is about
twice that for RR-5 houses, and three times that for
clustered housing.
Agriculture
1. Agricultural habitats remain at about 19-20%of the area of the impact region for all scenarios,just slightly higher than the proportion within theWRB.
2. Grass/tall” habitat occupies over 80% of theagricultural area in the impact region in all sce-narios.
(10,000)
(5,000)
0
5,000
10,000
15,000
20,000
5-acre parcels
15-acre parcels
clusters conserv.clusters
Cha
nge
in a
rea
with
res
pect
to P
TE
X (
acre
s)
-6,224
14,833
10,419
4,254
Net change is shown on the bars
Bare, burnt, fallowGrass tallGrass shortLeafy vegetablesVineyards, berriesOrchards, hybrid poplarChristmas trees
Fig� ���� Comparison of the change inagricultural habitats within the impact region�for all alternative futures with respect to PT�EX�
���
3. Agricultural habitats increase most in RR-15due to small-scale farming; increases in RR-CL andRR-CONS scenarios are due to firebreak vegetationwith pasture grass.
Under PT-EX scenario, there is a net loss of
9,180 acres of agricultural habitat from 1990 to 2050
within the impact region. Over 8,100 acres of
“grass/tall” habitat is lost to development in RRZs,
succession, and other crops. Of the other alterna-
tive futures, there is further loss of this habitat under
RR-5 due to the more intense development of the
ROZ. The other three scenarios show gains with
respect to PT-EX conditions (Fig. 4.15). The largest
gain is in RR-15 in which agricultural habitats
increase by a total of 14,833 acres over PT-EX
acreages because of the land use changes associ-
ated with small farming activities in the 15-acre
parcels. In the cluster scenarios, “grass/tall” habitat
is more than 11,800 acres larger than that of PT-EX
due to the use of pasture grass in the firebreaks
around the clusters. Additional restoration activities
in RR-CONS reduce all other agricultural habitats
with respect to PT-EX.
Natural Vegetation
1. In 1990, the impact region had proportion-ately more mixed forests and shrub than WRB, andless old growth conifers.
2. Conversion of natural vegetation to othercategories is least in PT-EX, and greatest in the RR-15 landscape. Among the RR scenarios, it is leastin RR-CONS.
3. All scenarios except RR-CONS show acontinuing trend toward more closed conifer forests,and less of all other natural communities.
In pre-settlement times, the impact region had
proportionately more mixed forests, prairie, oak
savanna, and shrub habitats, and less conifers than
the WRB as a whole (Figs. 4.9 and 4.13). This
reflects the location of the impact region along the
foothills where the dynamics of succession were
altered by frequent fires. Since 1850, mixed forests
and agricultural areas have increased by large
amounts, displacing prairie and oak savanna
habitats. Nevertheless, perhaps in an echo of the
past, 1990 conditions in the impact region show
proportionately more shrub and mixed forests, and
less conifers (with a much reduced old growth
component) in comparison to the composition of the
WRB.
The net loss in natural habitats (including
conifers) from 1990 to 2050 is only 0.1% within the
impact region for PT-EX; with development within
the ROZ, this loss increases to 4.1% in RR-15. Of
the alternative RR futures, RR-CONS has the least
loss at 3.4%. As Fig. 4.13 shows, the changes by
scenario in the vegetative composition of the region
are small - there is no more than a 4% difference
across any habitat (36,260 acres). However, for
rarer habitats, some of the changes are very
substantial. Appendix A.10 tabulates these changes
as a percent of the habitat present in the impact
region in 1990.
As mentioned above, old growth conifers
continue to be logged out and replaced with young
trees. Under all scenarios, the loss within the impact
region ranges from 45% (PT-EX) to 50% (RR-5 and
RR-15 scenarios). These amounts are approxi-
mately 4% of the 1990 inventory in the WRB.
Within some relatively rare habitats within the
WRB, significant changes in the impact region are
large enough to be significant basinwide. Habitats
“tree/open upland”, “grass/natural”, “seasonal
wetlands,” and “oak savanna” all show large
percentage increases over 1990 (Table 4.8). The
habitat “tree/open upland” increases under the RR-5
and RR-15 scenarios due to the opening of the
forests by processes associated with residential
development in the upland regions.2 Because of the
different form of development, the cluster scenarios
did not have this effect. The other habitats increase
in scenario RR-CONS due to restoration efforts.
Thus, the small area of land use/land cover change
within the ROZ under the alternative RR policies can
potentially have a large impact on species that rely
on these rare habitats.
LU/LC AND HABITAT CHANGES � How is habitat expected to change under the alternative futures?
���� RESULTS
How much and what type of habitat
is restored in the conservation clus-
ters future?
With the mitigation formula described in
“Chapter 2: Methods”, 84,819 acres of habitat are
designated for conservation/restoration within the
ROZ in the RR-CONS scenario. The location of the
targeted taxlots, the pre-settlement vegetation, and
the 1990 LU/LC determined both the restoration
objectives and the restored habitat classes (Fig.
4.16). The restoration area occupies 31.3% of the
taxlots of the ROZ, 19% of the impact region, and
1.2% of the WRB.
There are multiple types of restoration objec-
tives throughout the designated restoration areas of
the RR-CONS landscape. Oak savanna restoration
is the largest area at 38,136 acres. This is followed
by old-growth conifer restoration at 29,218 acres,
and prairie restoration at about 11,500 acres. For
comparison, consider the stakeholder-approved
areas of conservation reserves designated by PNW-
ERC in the Conservation Scenario of the WRB TOC
project. Among other habitats, these contained
55,200 acres of oak savanna, 53,120 acres of mid-
elevation conifer forests, and 37,900 acres of wet
and upland prairie. The mitigation areas of this
project supply from 30% to 69% of the habitat areas
of the PNW-ERC designed reserves.
Fig. 4.16 shows the habitat classes present in
the 2050 landscape of the restoration areas. As
described earlier in Chapter 2, the restored land
cover is a mosaic within the designated areas, and
depends to some degree on vegetation present in
1990, and on the time elapsed since restoration
began. By 2050, about 27,000 acres of oak
savanna have been added to the landscape of RR-
CONS, with 14,900 acres of upland prairie and
4,700 acres of wet prairie/seasonal wetlands.
What does the landscape look like?
A small area was chosen within the impact
region for the purposes of illustrating the land use/
land cover and habitat differences between the
scenarios. In addition to the maps, several land-
scape visualizations were also prepared
The area chosen encompasses the Spencer
Creek watershed, south of Eugene, Oregon, and is
about 35,000 acres or 54.5 sq. mi. Here, a rela-
tively large number of taxlots are chosen for the
ROZ due primarily to the generally poor productivity
of the watershed’s shallow soils. See Fig. 3.7 for the
location of these taxlots, and for the roads in the
area. About 1,189 rural residences were estimated
present in 1990, and this increased to 2,416 in the
RR-5 scenario.
Fig. 4.17 (a)-(f) shows the habitat mapping for
each of the scenarios excluding RR-CL. The most
striking differences are between the 1850 and the
modern landscapes. This area was predominately
oak savanna and upland prairie in pre-settlement
Habitat
Area present in
1990 (acres)
Change in area in WRB
Trend for
WRBTrend for
impact region
Change in
WRB
Change in
impact region
Tree open/upland 15,631 -1,477 declining slight increase RR-5, RR-15 +7,830 +9,411Grass/natural 22,041 -4,478 declining declining RR-CONS +9,532 +13,211Seas.wetlands 27,081 -2,584 declining declining RR-CONS +1,694 +4,032Oak savanna 0 - extinct extinct RR-CONS +26,665 +26,665
Trend Reversing Scenario
area within
(acres)
area within
(acres)(acres)
PT-EX Scenario, 2050
Scenario
Table �� � Comparison of trends in rare habitats of the WRB� “Trend reversing” scenarios are those thatreverse the trend seen in the PT�EX� This table shows� for example� that relative to ���“grass/natural”habitatdecreases by ���� acres in PT�EX� In RR�CONS� however� this habitat type increases in area by������ acres within the impact region (due to restoration)� Over the entire basin� the increase is less ������ acres� i�e�� this habitat is decreasing outside the impact region with a loss of (������ � ����) or ��acres�
����
26,918
14,920
11,209
7,879
4,982 4,7433,718 3,320
2,197 1,828 899 604 573 431 397 161 42-
5,000
10,000
15,000
20,000
25,000
30,000
oak
sava
nna
natu
ral g
rass
fore
st, c
lose
dca
nopy
, mix
ed
fore
st, c
lose
d ca
nopy
,ha
rdw
ood
fore
st, c
lose
d ca
nopy
,co
nife
rs 0
-20
yrs
seas
onal
wet
land
s/w
et p
rairi
e
fore
st, c
lose
d ca
nopy
,co
nife
rs 2
1-40
yrs
fore
st, c
lose
d ca
nopy
,co
nife
rs 8
1-20
0yrs
fore
st, c
lose
d ca
nopy
,co
nife
rs 4
1-60
yrs
wet
shr
ub
fore
st, c
lose
d ca
nopy
,co
nife
rs 6
1-80
yrs
upla
nd fo
rest
, sem
i-clo
sed
cano
py, m
ixed
upla
nd fo
rest
, sem
i-clo
sed
cano
py, c
onife
r
upla
nd fo
rest
, sem
i-clo
sed,
hard
woo
d
fore
st, c
lose
d ca
nopy
, c
onife
rs >
200y
rs
upla
nd fo
rest
, ope
n
wat
er
Are
a (a
cres
)
Habitat Classes
oak savanna 38,136 45%conifer forest 29,218 34%upland prairie 8,319 10%wet prairie 3,184 4%wetlands 2,394 3%mixed forest 2,340 3%floodplain/riparian forest 1,229 1%
total 84,819 100%
Restoration objective acres %
Fig� ����� Extent of restoration delineated in the ��� RR�CONS scenario� The areas designated fordifferent types of restoration within the taxlots of the ROZ are listed� The habitat classes present in therestoration areas in ��� are plotted� Note that these may be in transition to the final restoration typeto be achieved beyond ����
times. As the 1990 maps shows, increasing conifer
cover has drastically changed the oak areas, while
rural development and agriculture has displaced
much of the upland and wet prairie. Under PT-EX,
the 2050 landscape reflects the increased logging of
younger forests, the growth of the Eugene urban
area into the watershed, and the additions of rural
dwellings inside the RRZs. Under RR-5, and RR-
15, the increase in rural development is prominent.
Finally, RR-CONS shows the addition of restoration
areas to the landscape, and new rural houses within
clusters.
Fig 4.18 provides 3D visualizations of the
1850, 1990, PT-EX scenario, and 2050 RR-CONS
scenario. Here the openness of the historic land-
scape is contrasted markedly with the landscapes of
today and those simulated for the future. Clearly,
the changes in the restoration areas of RR-CONS
make only very small inroads into moving the
landscape structure back toward that of 1850. The
dominant pattern in the 2050 landscapes is that
created by forest management with a much higher
frequency of regenerating clearcuts than in 1990.
While there are abrupt changes between RR-CONS
restoration areas and adjacent land uses, similar
disjoint patterns exists with clearcuts, and between
farms and forests.
LANDSCAPE PROPERTIES � what does the landscape look like?
���� RESULTS
Fig� ����� Habitat maps for � �� �� and all alternative futures except RR�CL� The area encompassesthe Spencer Creek watershed� south of Eugene� OR� See Appendix A��b for the legend; each whitesquare represents the ��acre area surrounding a rural dwelling�
(b) ��
(c) PT�EX
(a) � �
S
N
Eugene
����
(d) RR�
(e) RR��
(f) RR�CONS
S
N
LANDSCAPE PROPERTIES � what does the landscape look like?
0 1 2 3 4 5 6 7 81
Miles
���� RESULTS
Fig������ Visualizations of Spencer Creek Watershed in ���� �� and in ���� under plan trend scenarioPT�EX and conservation cluster scenario RR�CONS� All visualizations were modeled from the land use/land cover maps of each scenario by David Diethelm Institute for a Sustainable Environment Universityof Oregon in collaboration with the author�
(a) USGS map draped over terrain in Spencer Creek focal area� A ��� acre square grid is applied�The black outlines are the taxlots of the ROZ in this area� The white areas within these outlinesare lower valued resource lands� This view is looking slightly east of north toward Eugene�
(b) Circa ���� pre�settlement landscape (PESVEG)
Eugene
����
(d) ���� plan trend landscape (PT�EX)�
(e) ���� conservation clusters scenario landscape (RR�CONS)�
(c) �� current conditions landscape (CC�)�
LANDSCAPE PROPERTIES � what does the landscape look like?
���� RESULTS
SPECIES RESPONSES TO HABITATCHANGES
Each species can be thought of as an “integra-
tor” of a mosaic of land use/land cover within the
spatial container that is its range. The effect of
changes in habitat conditions in one part of a
species range can be offset by changes in another.
Changes outside its range are irrelevant to that
species. Thus, the definition of the analysis area is
important to the results and to any question regard-
ing persistence of a species in a changing land-
scape.
This section will evaluate results from the
habitat evaluation model. Several different types of
analysis are reported. First, changes in local
species richness from 1990 to 2050 are compared
across the alternative landscapes. Second, species
responses to habitat change are compared both
across the entire basin, and in the impact region.
Individual species for which habitat changes are
significant are identified. Finally, habitat trends for a
group of oak and grassland species are compared
for PT-EX and RR-CONS.
How does local species richness
change from 1990 to 2050?
1. Local species richness fluctuates spatiallybased on local changes in LU/LC. By 2050, underall scenarios, 17 - 18% of the WRB has increased
species richness over 1990 conditions; 21 - 22%has decreased richness.
2. Lower average local species richness isexpected with increased development. New ruralresidential development reduces native speciesrichness over more area than occurs with no suchdevelopment. Further, there is less area of increas-ing species richness under all alternatives to plantrend.
3. Habitat restoration does not necessarilyincrease local species richness. The trend dependson which habitat type is replaced , and which habitattype is restored.
Table 4.9 summarizes, for native vertebrate
species in breeding habitats, the area over which
changes in richness occur. Figure 4.19 shows the
spatial distribution of these changes under PT-EX
policies from 1990 to 2050, and for 1850 with
respect to 1990. The maps for the alternative
futures are indistinguishable from that of PT-EX at
this scale.
While species richness remains static at over
61% of the WRB under PT-EX, there is a small bias
(400 sq. mi.) toward more area with reduced
species richness. Areas that are taken within UGBs
by 2050 show a large decrease in richness. The
uplands show an overall decrease, while the
margins of the valley indicate an increase. These
trends are primarily due to the shifting age distribu-
plan trend5-acre parcels
15-acre parcels
conserv.clusters
< -50 123 126 149 141 150 81 -11 - -50 1,525 1,590 1,572 1,553 1,574 1,022 -1 - -10 774 818 799 792 789 2,278
0 unchanged 7,033 6,941 6,951 6,965 6,910 1,083 1-10 1,019 1,001 1,010 1,021 1,027 1,827
11-50 974 971 967 975 994 4,107 > 50 30 30 30 30 33 1,080
net area change (1) -400.1 -531.2 -512.6 -460.7 -459.6 3632.8% of WRB -3.5% -4.6% -4.5% -4.0% -4.0% 31.7%(1) area with increased richness - area with decreased richness
area (sq. miles)2050
clusters 1850
Change in number of
species relative to
1990
Table ��� Total area overwhich various intervals ofchange in the number of nativevertebrate species occurs� Thisis for analysis of breedinghabitat within the entire WRB�
����
2468
Area (thousands of sq.mi)
< -50
-11 - -50
-1 - -10
1 - 10
11 - 50
> 50
0
plan
tren
d
chan
ge in
num
ber
of s
peci
es
SN
2468
Area (thousands of sq.mi)
< -50
-11 - -50
-1 - -10
1 - 10
11 - 50
> 50
0
chan
ge in
num
ber
of s
peci
es
1850
Fig
� �
��
� C
ha
ng
es
in n
ati
ve
spe
c ie
s ri
c hn
ess
wit
hin
bre
ed
ing
ha
bit
ats
of
the
WR
Bfo
r th
e (
a)
PT
�EX
la
nd
sca
pe
�a
nd
b)
pre
�se
ttle
me
nt
lan
dca
pe
� re
fere
nce
d t
o �
�co
nd
itio
ns�
Th
e h
isto
gra
ms
sho
w t
he
su
m o
f th
e a
rea
s in
ea
ch c
ate
go
ry�
Th
e c
olo
rs a
reth
ose
of
the
ma
p�
SPECIES RESPONSES TO HABITAT CHANGES � How does local species richness change?
200
20
Mile
s
��� RESULTS
tion of the closed conifer forests. Fig. 3.10 suggests
that local species diversity in closed conifer forests
can decrease in the 40 years following logging and
may only exceed the diversity present in clearcuts
once the forest ages beyond 80 years. Thus, in
areas of recent clearcuts, species diversity is
expected to increase (at least temporarily). In areas
where richer mixed forests or hardwood forests are
replaced by conifer forests (60 years and older)
through succession, species diversity decreases.
The species assemblage also changes with these
habitat changes.
In all alternative futures, the results are very
similar. This is due to the underlying dominant plan
trend policies and practices which define over 96%
of the LU/LC in the WRB. That is, given that the
size of the ROZ is 425 sq. mi. and that more than
half remains in resource use (following PT-EX), the
WRB-wide trends are little affected no matter what
alternative policies are adopted. Species richness
under RR-5 policies has the largest area of de-
crease, and the smallest area of increase. That is,
LU/LC changes under RR-5 tend to negatively bias
species richness. Under RR-CONS, more area has
lower species diversity and more area has higher
species diversity. This is due to both development,
and to restoration activities. The latter can increase
species richness when agricultural areas are
restored to native habitats such as “grass/natural.”
Restoration can also result in decreases in local
species richness when mixed forests are replaced
with oak savanna.
For insight into restoration issues, consider the
pre-settlement scenario of 1850 (Fig. 4.19(b)). Here,
spatial trends in changes in species richness vary
dramatically. When compared with 1990 conditions,
local species richness in 1850 is higher in over 61%
of the WRB area. It stays the same in only 9%, and
decreases over 29% of the area. In fact, more area
(approximately 3,381 sq. mi.) is species poor in
1850 than in 1990. Note the lower number of
species in the foothills — this is due to the presence
of oak savanna in 1850 compared with mixed and
hardwoods forests in 1990. The latter are preferred
by more species than the former. The greater
richness in the lowlands of 1850 is due to the
presence of prairies, more highly preferred by native
species than the crops of 1990. These results show
clearly that restoring habitat to pre-settlement
conditions can either increase or decrease species
richness in an area, depending on what was present
prior to restoration, and what habitat is restored.
Again, note that this result does not reflect which
species are present or absent; it merely counts the
number present. Thus, the species mix can change
significantly although the alpha diversity remains
relatively constant.
Within the area of the ROZ affected by the
alternative RR scenarios, local species diversity
decreases over more area than it increases under
all scenarios. That is, there is a bias toward lower
richness.
For what species are habitat condi-
tions improving or declining?
A larger diversity of habitats supports a larger
species diversity across the landscape. When some
of these habitats become rare either because of
land use practices and/or succession accompanied
by lack of natural disturbances, specialist species
decline. There are 49 vertebrate species that are
rare or threatened within the WRB (Appendix A.1,
ODFW Status)
In the next section, the trends in habitat
conditions from 1990 to 2050 for each terrestrial
vertebrate species is examined for each scenario.
As discussed in Chapter 3, increasing cumulative
habitat scores are assumed to reflect improved
conditions that enhance the long term survival of the
species in the area, and that may lead to increased
populations. Conversely, decreasing habitat scores
are assumed to indicate declining quantity and
quality of habitat that are likely to support smaller
populations at greater risk of extirpation.
Species Trends within the WRB under PT-EX
Table 4.10(a) summarizes the response of all
species to changes in breeding and feeding habitats
across the WRB. I will discuss only breeding habitat
changes here. The number of species for which
���
-10
0
10
20
30
40
-10
0
10
20
30
40
plan trend
conserv.cluster 18505-acre 15-acre clusters
No.
Spp
Incr
easi
ng -
N
o. S
pp D
ecre
asin
g
plan trend
conserv.cluster 1850
all b
reedin
g sp
ecie
sBasin Impact Region
native, incl. rare native, rare only extirpated introduced
All Species Habitat type and Species group In
crea
sing
(1)
Dec
reas
ing
(2)
Unc
hang
ed (
3)
Incr
easi
ng
Dec
reas
ing
Unc
hang
ed
Incr
easi
ng
Dec
reas
ing
Unc
hang
ed
Breeding habitat
native, incl. rare 54 51 149 85 55 114 136 52 66native, rare only 5 8 25 11 7 20 23 3 12extirpated 1 1 4 1 2 3 4 2 0introduced 8 0 8 11 0 5 4 9 3
Feeding habitatnative, incl. rare 52 44 158 87 49 118 131 46 77native, rare only 3 5 28 6 6 24 18 2 15extirpated 2 0 4 2 0 4 5 1 0introduced 8 0 8 11 0 5 4 9 3
plan trendconserv. clusters 1850
Trends of Habitat Change within the Impact Region
All Species Habitat type and Species group In
crea
sing
(1)
Dec
reas
ing
(2)
Unc
hang
ed (
3)
Incr
easi
ng
Dec
reas
ing
Unc
hang
ed
Incr
easi
ng
Dec
reas
ing
Unc
hang
ed
Incr
easi
ng
Dec
reas
ing
Unc
hang
ed
Incr
easi
ng
Dec
reas
ing
Unc
hang
ed
Incr
easi
ng
Dec
reas
ing
Unc
hang
ed
Breeding habitat
native, incl. rare 25 33 199 32 36 189 29 36 192 29 35 193 35 28 194 163 52 42native, rare only 3 6 31 6 6 28 5 6 29 5 6 29 8 5 27 33 4 3extirpated 1 1 4 1 1 4 1 1 4 1 1 4 1 1 4 4 1 1introduced 7 0 9 8 0 8 8 0 8 8 0 8 9 0 7 3 11 2
Feeding habitatnative, incl. rare 21 26 210 23 29 205 21 28 208 21 28 208 26 24 207 161 51 45native, rare only 1 4 33 1 4 33 1 4 33 1 4 33 3 4 31 30 4 3extirpated 2 0 4 2 0 4 2 0 4 2 0 4 2 0 4 5 0 1introduced 7 0 9 8 0 8 8 0 8 8 0 8 9 0 7 4 10 2
plan trendconserv. clusters5-acres 15-acres clusters 1850
Trends of Habitat Change within the WRB
Table ����� Number of species withincreasing� decreasing� or unchangedsummed habitat scores for differentscenarios relative to ���(a� above) Analysis area is the WRB�(b� left) Analysis area is the impact region�
(�) the number of species with scoresgreater than ���� of �� scores;(�) the number of species with scores lessthan �� of �� scores;(�) the number of species for whichchange in habitat score with respect to�� is between ± ����Note: pika� lynx and wolverine are notpresent in the impact region and are notincluded in the counts�
Fig� ����� Net number of species increasing for different scenarios relative to ��� categorized byconservation status� (a) analysis area is the WRB� (b) analysis area is the impact region�
(a)
(b)
SPECIES RESPONSES TO HABITAT CHANGES � For what species are habitat conditions improving or declining?
(a) (b)
���� RESULTS
SPECIES1990
Presence (sq.mi.)
Status
BIRDSLincoln's Sparrow -91% 11 N
Lark Sparrow -26%
Yellow-Rumped Warbler -21% 1,180 N
California Condor -20% 3,198 E
Fox Sparrow -18% 307 N
Vesper Sparrow -18% 358 N/Sc
Red-Shouldered Hawk -17% 59 N
Wood Duck -17% 917 N
Hooded Merganser -15% 1,548 N
White-Tailed Kite -15%
Hutton's Vireo -14% 3,468 N
Barrow's Goldeneye -13% 108 R
Black-Capped Chickadee -13% 1,734 N
Brown Creeper -12% 6,359 N
Downy Woodpecker -12% 924 N
Red-Breasted Sapsucker -12% 6,068 N
Spotted Owl -11% 5,047 R
Green Heron -11% 584 N
Mourning Dove -11% 771 N
Western Screech-Owl -11% 7,019 N
Barred Owl -11% 6,068 N
Chestnut-Backed Chickadee -11% 5,139 N
Northern Goshawk -10% 1,259 R/Sc
Bufflehead -10% 78 R
Pileated Woodpecker -10% 5,816 N/Sv
Common Snipe -10% 203 N
MAMMALSGoldenMantled Grnd Squirrel -13% 48 N
HERPSWestern Rattlesnake -19% 137 N/Sv
Dunn's Salamander -17% 2,696 N
Ensatina -14% 5,044 N
Oregon Slender Salamander -13% 1,948 R
Clouded Salamander -10% 3,830 N
-10% 4,634 N
Change in
Scored Habitat
4 R
1 N
Western Red-Backed Salam.
Pacific-Slope Flycatcher -11% 5,168 N
Decreasing Scores
SPECIES
Change in
Scored Habitat
1990 Presence (sq.mi.)
Status
BIRDSMountain Quail 10% 3,077 N
White-Crowned Sparrow 11% 1,402 N
Macgillivray's Warbler 11% 961 N
American Crow 13% 784 N
Orange-Crowned Warbler 14% 1,501 N
Peregrine Falcon 14% 66 R
Barn Owl 15% 291 N
Violet-Green Swallow 15% 985 N
Anna's Hummingbird 20% 657 N
Willow Flycatcher 24% 1,281 N/Sv
House Sparrow 24% 658 I
Western Bluebird 25% 1,144 N/Sv
Townsend's Solitaire 26% 892 N
Dusky Flycatcher 27% 776 N
Rock Dove 28% 420 I
Marbled Murrelet 28% 62 R
Golden Eagle 35% 197 N
Lazuli Bunting 36% 683 N
Common Nighthawk 37% 972 N/Sc
Rock Wren 42% 35 N
Purple Martin 43% 914 R/Sc
Wrentit 49% 429 N
American Kestrel 50% 868 N
Tree Swallow 52% 560 N
Lewis' Woodpecker (1) 3,366% 0 E/Sc
MAMMALSEastern Fox Squirrel 11% 6,188 I
Hoary Bat 18% 8,811 N
California Vole 23% 713 N
House Mouse 24% 6,672 I
Black Rat 24% 6,585 I
Norway Rat 24% 6,585 I
Eastern Gray Squirrel 27% 3,030 I
HERPSWestern Fence Lizard 13% 1,548 N(1) This large change is due to the very small "presence" area of the species in 1990 and a small addition of habitat in 2050.
Increasing Scores
Table ����� List of species showing significant responses to changes since �� in habitat scores underPT�EX scenario� basinwide� Rare species are highlighted� “Presence area” refers to the area in whichhabitat scores are or greater (indicative of a higher likelihood of the species persistence)� Status: N �native� R� rare native� E � extirpated� I � introduced� Sc � State critical list� Sv � State vulnerable list�
scored habitat improves, deteriorates, or remain
unchanged with respect to 1990 conditions, is listed
for each alternative future and for 1850. Only
differences exceeding +/-10% in the cumulative sum
of the scores are considered significant. Fig. 4.20(a)
plots the net change in the number of species
experiencing significant changes in breeding habitat
scores, referenced to 1990 (this charts the number
of “winners” over the number of “losers”). These
results were condensed from Appendices A.12,
A.16, and A.20, which plot the response of each
species to changes in breeding habitat from 1990 to
2050.
Consider the effects of the PT-EX scenario.
The results show that for all native vertebrates
under this scenario, breeding habitat conditions
decline for 33 species (13%), improve for
����
0
4
8
12
16
20
Con
ifer
0-20
yrs
Con
ifer
clos
ed 2
1-40
yrs
Con
ifer
clos
ed 4
1-60
yrs
Con
ifer
clos
ed 6
1-80
yrs
onife
r cl
osed
81-
200
yrs
Con
ifer
clos
ed 2
00+
yrs
onife
r se
mic
lose
d up
land
Mix
ed fo
rest
clo
sed
Mix
ed fo
rest
sem
icl u
p
Har
dwoo
d cl
osed
Har
dwoo
d se
mic
l upl
Tre
e op
en u
plan
d
Oak
sav
anna
Shr
ub d
ry, t
ree
open
,....
Shr
ub w
et v
alle
y
Chr
istm
as tr
ee
Orc
hard
s, h
ybrid
pop
lar
Vin
eyar
ds, b
errie
s
Leaf
y ve
geta
bles
Gra
ss s
hort
Gra
ss n
atur
al
Gra
ss ta
ll
Bar
e, b
urnt
, fal
low
Roc
k m
onta
ne
Sno
w, i
ce m
onta
ne
Sea
sona
l wet
land
s
Lake
s, r
eser
voirs
, ...
Str
eam
s sm
all
Str
eam
s la
rge
Cha
nnel
gra
vel
Bui
lt hi
gh d
ensi
ty
Bui
lt m
id d
ensi
ty
Bui
lt lo
w d
ensi
ty
Roa
ds, r
ailro
adsl s
improving conditions deteriorating conditions
Num
ber
of S
peci
es
WRB, PT-EX scenario
Fig� ����� Comparison of breeding habitat preferences exhibited by selected groups of species� These resultsare for changes over the basin with respect to �� conditions� (a) Histogram of preferences exhibited byspecies with significantly improving habitat� unique to RR�CONS only� (b) Histogram of preferences exhibitedby species with significantly improving or deteriorating conditions in PT�EX landscape (see Table ���� for a listof these species)� Note that these histograms indicate the “potential” response of the species groups: ifhabitat area is not present or is unchanged� then the preference cannot be expressed in the change in thecumulative habitat scores� Thus� this figure should be considered when reviewing the change in habitat areas�
25 species (10% of the total number in the WRB),
and stay about the same for 199 species. Birds and
amphibians are more negatively affected than
mammals: conditions decline for 17% of native bird
species, and 28% of native amphibians. (See
Appendices A.11, A.15, and A.19 for summaries by
taxonomic group). Seven exotic species out of a
total of 16 present in the WRB have improving
conditions, while the rest are unaffected by the
changes in habitat.
Table 4.11 lists the species that show signifi-
cant responses. By examining the preferred habitats
of those species showing negative responses
versus those with positive responses, the major land
use/land cover changes contributing to these results
become clear. Fig. 4.21(b) shows the distribution of
preferred habitats (scores 5 or greater; see Fig. 3.9
for examples) for the group of “advantaged”
species, and for the group of “disadvantaged”
species. There is a clear shift between these
histograms. The species with improving habitat
conditions are those that prefer regenerating
clearcuts (“conifers 0-20 years”), built areas, and
more shrubby and open habitats. Those for which
conditions decline prefer old conifer forests, and
mixed and hardwood forests. The forestry practices
of the plan trend scenario, as discussed earlier, are
primarily responsible for these habitat shifts.
However, this conclusion is not universally appli-
cable to all species - range, and other adjacency
relationships can be important. This is shown in
Table 4.11: the Marbled Murrelet, dependent on old
growth conifer forests, is shown to have improving
0
2
4
6
8
Num
ber
of S
peci
es
WRB, RR-CONS scenario(a)
(b)
SPECIES RESPONSES TO HABITAT CHANGES � For what species are habitat conditions improving or declining?
���� RESULTS
conditions under PT-EX, while conditions decline for
the Spotted Owl. This occurs even though the owl
is more adaptable to habitat changes than is the
murrelet -- it utilizes some younger conifer forests
in addition to its most preferred old growth forests.
The murrelet’s range is limited within the WRB and
is confined to the Coast Range. By 2050, the
regrowth of BLM checkerboard forest land to old-
growth represents a relatively large habitat gain in
the small area available ca. 1990 to the species.
Species that prefer rare habitats are particu-
larly sensitive to changes in the available amounts
of those habitats. According to the habitat evalua-
tion model, the Lewis’ Woodpecker, for example,
has only a few acres of suitable habitat within its
range in the WRB. The addition of approximately
420 acres of “hardwood semiclosed upland” habitat
through succession creates a very large change
relative to the 1990 landscape wherein its habitat
area is calculated as less than 15 acres (Table
4.11). The average habitat score over this limited
area remains at 5.03 . Thus, while habitat for this
species is evaluated as improving under plan trend,
it is still extremely limited and of marginal quality,
indicating that the species remains at high risk of
extirpation within the basin4 . Further, it should be
emphasized that the landscape pattern of the
habitat may be important to a species in that a
certain patch size is required to function as a viable
territory. As discussed earlier, relational patterns
within and between habitat areas are not evaluated
here. Thus, any gains in habitat should be cau-
tiously interpreted as they may be optimistic. On
the other hand, declines in habitat scores can be
more confidently assumed to indicate negative
impacts on species.
The results indicate that of the species of
concern within the WRB, Vesper Sparrow, White-
tailed Kite, Barrow’s Goldeneye, Bufflehead,
Spotted Owl, Northern Goshawk, Pileated Wood-
pecker, Western rattlesnake, and Oregon slender
salamander are placed at greater risk under PT-EX
policies.
These are all species for which the 1850
landscape was much preferred in comparison to
1990 conditions. Evaluation of the species re-
sponses to the 1850 landscape is shown in Table
4.10(a) and Fig. 4.20(a): breeding habitat improves
for 163 species, and deteriorates for 52, with
respect to conditions in 1990. Clearly, the mix of
species was much different in the pre-settlement
landscape than in either 1990 or any of the alterna-
tive futures. Of the 46 native bird species with
increasing habitat scores under plan trend, 24
(52%) experience significantly declining conditions
in the 1850 landscape. Of the remaining 108 native
bird species with negative change in their habitat
scores under PT-EX, only 16 (15%) have declining
scores in the 1850 landscape. Thus, species that
favor land use/land cover changes under plan trend
(clearcuts, young conifers, and developed areas)
are negatively influenced by changes that move the
landscape back toward 1850 conditions. Species
that are adversely affected by land use/land cover
changes under plan trend (loss of old growth
conifers, grasslands) are positively influenced by
changes toward an 1850 landscape. Further, the
much reduced acreages in 1850 of mixed forests,
and wet shrub provide less habitat for some of the
warblers, vireos and blackbirds of the WRB.
Species trends in the WRB under alternative futures
Almost all of the species with significant
responses to scenario PT-EX react similarly under
the alternative RR futures. This is to be expected
given that landscape changes due to the activities in
the ROZ cover only a very small area of the WRB.
However, these changes do have incremental
effects that, when added to the changes elsewhere
within the basin, cause habitat trends for additional
species to be regarded as significant. This is typical
of small but widespread environmental changes that
when taken together add up to be of concern. It is
also suggestive of small-scale actions that by
themselves are not meaningful, but that can
accumulate and thereby improve conditions.
From Table 4.10(a) and Fig. 4.20(a), the
habitat evaluation model indicates that the conser-
vation cluster scenario, RR-CONS, provides better
habitat for more species than do any of the other
alternative futures, including plan trend. It is the
����
only future scenario in which conditions improve for
more native species (35) than decline (28). A similar
positive bias is exhibited for rare species with
habitat improving for 8 species versus deteriorating
for 5 species. This trend also holds true for intro-
duced species (9 species with increasing habitat
versus 7 under plan trend).
For all alternative RR futures, the change in
habitat scores of those species with a preference for
old growth conifer habitats are only slightly more
negative than changes under the plan trend
landscape. Additional logging of conifers to make
way for development and for restoration in the RR
futures depletes the older conifer habitat beyond
that which occurs under PT-EX.
Common among all futures is the negative
response of the western rattlesnake to increased
development (Appendix A.12). Only in the conserva-
tion cluster scenario is this offset by other changes -
the restoration of prairie areas. Under RR-CONS,
the habitat for this reptile declines but to less an
extent than occurs under plan trend and the other
alternative futures.
Also common among all RR futures is the
positive response, as indicated by the habitat
evaluation model, of the pallid bat, Townsend’s big-
eared bat, and, for RR-5 and RR-CONS, the
Brazilian free-tailed bat (Appendix A.16). As was
the situation for Lewis’ Woodpecker, the habitat
model indicates that there is very little habitat for
these species within the basin. Small changes in
the cumulative habitat score due to a low valued
habitat preference for the additional development
(“built low density”) result in score increases over
1990 conditions that are significant. For these
species, the increasing habitat scores are indicative
of increases in marginal habitat rather than source
areas5 , i.e. the habitat improvements are only of low
quality. Of the other mammals, habitat for the exotic
house mouse, Norway and black rats, and the
eastern gray squirrel increases.
Four bird species show common positive
responses to all alternative RR futures. These are
the Cliff Swallow, the Barn Swallow, the American
Goldfinch, and the European Starling (an introduced
species) — all species utilizing developed areas and
their environs (Appendix A.20). Further, in RR-5
with the greatest amount of developed area,
conditions also improve for the House Finch and
Bewick’s Wren. All are common within the WRB.
The RR-CONS landscape stands out from the
other RR scenarios because of the increase in
habitat area for a variety of species that exhibit
preferences for upland and wet prairie and savanna
habitats. Fig. 4.21(a) is the histogram of habitat
preferences for species with improving habitat
conditions unique to RR-CONS. They are the
ringneck snake, Lark Sparrow, Grasshopper
Sparrow, Acorn Woodpecker, and Wilson’s
Phalarope. Also included in this histogram are the
preferences of those species for which the habitat
trends exhibited in PT-EX are reversed under RR-
CONS. This includes the Lark Sparrow, Vesper
Sparrow, White-tailed Kite, Green Heron, Common
Snipe, and western rattlesnake. Again, many of
these species are present only in limited areas of
the WRB. Further, while not causing habitat scores
to increase significantly, the location of additional
ponds (for fire fighting) in the RR-CONS scenario
reverses declining trends for a number of duck
species (Appendix A.20). Other species such as the
Meadowlark and the Western Kingbird also showed
limited positive trends under RR-CONS, while the
habitat for the Lewis’ Woodpecker increased by
sixteenfold.
Overall, the species’ responses to the RR-
CONS scenario show a combination of different
trends — those relating to the loss of old-growth
conifer and increasing areas of young conifer
plantations outside the ROZ, to increasing develop-
ment, and to the increase in rare habitats of prairie
and oak savanna in the restoration areas. One
unfortunate side-effect of this more diverse mosaic
of habitats is that some introduced species are also
favored.
Species Trends within the Impact Region
The RR-CONS landscape was preferred over
all other alternative futures since it not only provided
SPECIES RESPONSES TO HABITAT CHANGES � For what species are habitat conditions improving or declining?
���� RESULTS
Table ����� Changes in habitat scores of selected native speciesunder plan trend� PT�EX� and conservation cluster scenario RR�CONS� with respect to �� conditions within the impactregion� These are species with more than �� of their WRBsource habitat within the impact region� Bold type indicates thepreferred scenario landscape� Shaded areas indicate significanttrends (changes greater than �/� ��� of �� scores)�
SPECIESplan trend
conserv. clusters
% WRB presence
in the impact region
presence area, WRB
1990 (sq.mi.)
HERPS
Long-Toed Salamander -6% 31% 18% 192 N
Ringneck Snake 21% 28% 21% 1,560 N
Western Skink 21% 27% 21% 1,560 N
Racer 12% 24% 23% 870 N
Sharptail Snake 13% 21% 21% 1,113 R/Sv
Gopher Snake 12% 20% 23% 876 N
Southern Alligator Lizard 15% 18% 23% 849 N
Western Pond Turtle -7% 15% 16% 867 R/Sc
Western Rattlesnake -21% -8% 28% 137 N/Sv
Western Red-Backed Salamander -15% -24% 17% 4,634 N
Dunn's Salamander -19% -28% 18% 2,696 N
MAMMALS
Pallid Bat 1% 57% 33% 49 R/Sv
Brazilian Free-Tailed Bat -1% 26% 47% 5 R
California Vole 29% 25% 48% 78 N
Townsend's Mole 9% 15% 15% 3,052 N
Townsend's Vole -10% -2% 17% 2,224 N
BIRDS
Lewis' Woodpecker (1) 50% 54933% 95% 0 E
Lark Sparrow -16% 1402% 29% 1 N
American Kestrel 87% 94% 16% 868 N
Grasshopper Sparrow -8% 87% 27% 9 R
Vesper Sparrow -17% 81% 24% 358 N/Sc
Wrentit 72% 61% 22% 429 N
Acorn Woodpecker 8% 58% 23% 337 R
Western Meadowlark -9% 56% 23% 34 N/Sc
Common Snipe -11% 45% 18% 203 N
American Goldfinch 17% 38% 18% 1,458 N
Northern Harrier -9% 29% 20% 164 N
Lesser Goldfinch -7% 29% 19% 854 N
Chipping Sparrow 9% 23% 15% 710 N
Bewick's Wren 19% 19% 20% 1,455 N
Cedar Waxwing 11% 17% 16% 1,475 N
White-Tailed Kite -15% 12% 38% 4 R
Brown-Headed Cowbird 5% 11% 18% 962 N
Virginia Rail -12% 6% 16% 191 N
Red-Shouldered Hawk -11% 0% 23% 59 N
Purple Finch -5% -13% 19% 4,441 N
Marbled Murrelet -11% -13% 16% 62 R
Long-Eared Owl -11% -18% 20% 871 N
(1) This result is sensitive to the very small area of habitat present in 1990
Change in scored habitat within impact region
Status
enhanced habitat conditions for almost
all species favored by the RR-5, RR-15
and RR-CL scenarios, but also for an
additional number of species of
concern. Given this result, the changes
within the impact region were analyzed
for scenarios PT-EX, RR-CONS and the
1850 landscape only. Table 4.10(b) and
Fig. 4.20(b) summarize the results.
Appendices A.13, A.17 and A.21 show
each species’ response to the land-
scapes. In this smaller area, LU/LC
changes are more in scale with the size
of the region. Consequently, species are
more sensitive to these changes which
are no longer buffered by the large area
outside the impact region.
Under RR-CONS, habitat condi-
tions significantly improve for 85 native
species compared with 54 species
under PT-EX. Further, conditions
deteriorate for 55 species in the RR-
CONS scenario, compared with 51
species under PT-EX. Thus, there are
improved conditions for a net of 30
species under RR-CONS scenario
versus only 3 under PT-EX. Appendi-
ces A.14, A18 and A.22 compare the
results for taxonomic groups. Overall,
reptiles, amphibians, and birds are likely
to do better in the RR-CONS landscape
than in that of PT-EX; mammals are at
more risk.
The habitat changes within PT-EX
are compared with those in RR-CONS
in Appendices A.8 and A.10. Under PT-
EX, changes in the impact region are
mostly due to increases in young
conifer habitats and in development,
and to decreases in older conifers,
mixed forests and shrub. Under RR-
CONS, young conifers increase by
almost as much as in PT-EX; old growth
and mixed forest decrease more than
PT-EX; development is about double
the 1990 area. Also, there are substan-
���
tial increases in the restored habitats of upland
prairie (a 256% increase over 1990 area), wet
prairie/seasonal wetlands (a 140% increase), and
26,665 acres of oak savanna. This more diverse
mosaic of habitats with greater areas of relatively
rare habitats accounts for the generally favorable
species responses to the RR-CONS landscape.
However, the larger reduction in old growth conifers,
mixed forests and shrub, cause some species that
prefer these conditions to react more negatively
than they do to the PT-EX landscape.
Consider first those species with habitat
concentrated within the impact region6 . Table 4.12
compares significant scored habitat changes under
PT-EX and RR-CONS for these species. Of the 11
amphibians and reptiles, the RR-CONS landscape
changes are positive and more favorable than PT-
EX for eight species. The habitat for the western
rattlesnake deteriorates under PT-EX but is not
significantly changed under RR-CONS. Habitat for
two salamanders deteriorates under both scenarios,
and is worse under RR-CONS. This is due to the
preference of these amphibians for older conifers,
and closed mixed and hardwood forests — habitats
that decline in area under both scenarios within the
impact region.
Of the five mammals listed in Table 4.12, four
have strong positive responses to habitat changes
under RR-CONS, with one of the four, the California
vole, preferring the PT-EX landscape. Habitat for the
Townsend’s vole declines under PT-EX and is
unchanged under RR-CONS.
Of the 22 birds listed in Table 4.12, 17 species
have improved habitat under RR-CONS, while
conditions deteriorate for 3 species which prefer old
growth conifer, mixed and hardwood forests, and/or
21-40 year conifers. Although these species --
Purple Finch, Marbeled Murrelet, and Long-Eared
Owl, do better under PT-EX than RR-CONS, their
habitat scores decline significantly under both
scenarios within the impact region.
Thus, from the perspective of species with
existing (1990) habitat concentrated in the impact
region, two salamanders and three bird species are
SPECIESplan trend
conserv. clusters
HERPS
Cascades Frog -1% 164% R/Sv
Western Toad -2% 52% N/Sv
Sharptail Snake 13% 21% R/Sv
Western Pond Turtle -7% 15% R/Sc
Western Rattlesnake -21% -8% N/Sv
Cascade Torrent Salamander -5% -10% R/Sv
Tailed Frog -11% -16% R/Sv
Oregon Slender Salamander -29% -36% R
MAMMALS
Townsend's Big-Eared Bat 18% 88% R
Pallid Bat 1% 57% R
Brazilian Free-Tailed Bat -1% 26% R
American Marten 13% 0% R
Long-Legged Myotis -8% -11% R
Fisher -2% -12% R
White-Footed Vole -6% -15% R
BIRDS
Lewis' Woodpecker (1) 50% 54,933% E/Sc
Purple Martin 148% 111% R/Sc
Black Tern -8% 110% R
Western Bluebird 76% 88% N/Sv
Grasshopper Sparrow -8% 87% R
Common Nighthawk 112% 86% N/Sc
Vesper Sparrow -17% 81% N/Sc
Acorn Woodpecker 8% 58% R
Western Meadowlark -9% 56% N/Sc
Willow Flycatcher 68% 51% N/Sv
Peregrine Falcon 49% 49% R
Ring-Necked Duck -1% 39% R
Bald Eagle -6% 14% R
White-Tailed Kite -15% 12% R
Bufflehead -21% -8% R
Marbled Murrelet -11% -13% R
Olive-Sided Flycatcher -6% -14% N/Sv
Barrow's Goldeneye -29% -18% R
Northern Goshawk -17% -21% R/Sc
Pileated Woodpecker -18% -24% N/Sv
Spotted Owl -24% -32% R
Change in scored habitat within impact region
status
(1) This result is sensitive to the very small area of habitat present in 1990
Table ����� Response of rare and sensitivespecies within the impact region to changes inhabitat due to scenarios plan trend� PT�EX� andconservation clusters� RR�CONS� Only specieswith significant habitat changes are listed� Boldtype indicates the landscape preferred by thespecies� Shaded boxes indicate significanttrends�
SPECIES RESPONSES TO HABITAT CHANGES � For what species are habitat conditions improving or declining?
���� RESULTS
adversely affected by implementation of RR-CONS
policies. Conditions for four of these five species
also decline under PT-EX, but to a lesser degree.
Eighteen bird species, four mammals, and 9 herps
do better under RR-CONS than they would under
continuation of plan trend policies.
Consider now rare and sensitive species that
are present in the impact region (Table 4.13). Of the
eight amphibian and reptile species, conditions are
more favorable under RR-CONS for 5 species, with
negative results for two salamanders (different
species from those in Table 4.12) and the tailed
frog. For the mammal group, three bat species that
utilize low density built habitats prefer the RR-CONS
landscape. Three mammals that prefer older closed
forests — the fisher, long-legged myotis, and the
white-footed vole, potentially decline in the RR-
CONS landscape, while remaining stable under PT-
EX (within the criteria of “significance”).
Twenty-one rare and sensitive birds are
present in the impact region, according to the
evaluation model. Of these, 14 have positive
responses to the changes under RR-CONS. Five of
the six species with negative responses to RR-
CONS would do better under PT-EX conditions,
according to the evaluation model, but still poten-
tially decline. These include the Marbeled Murrelet,
Spotted Owl, Pileated Woodpecker, Northern
Goshawk, Barrow’s Goldeneye, and Olive-sided
Flycatcher, a cohort of old-growth and closed forest
breeders.
Thus, of the 36 rare and sensitive vertebrate
species in the impact region, habitat conditions
improve for 21 species in the RR-CONS landscape
versus nine for the PT-EX landscape. Of the sixteen
species that would do better under PT-EX scenario,
habitat scores improve for only five species and
decline for the rest.
The Marbled Murrelet is the only rare species
with habitat concentrated in the impact region. Its
dependence on old growth conifer forests results in
habitat decline under both scenarios, with the RR-
CONS landscape being somewhat more detrimen-
tal to the species due to the increased loss of
conifers from logging for development and for
restoration.
For the PT-EX scenario, all but a few rare and
sensitive species have similar responses within the
impact region as they do basinwide (Tables 4.11
and 4.13). The exceptions are the sharptail snake,
American marten, Townsend’s big-eared bat (all with
positive trends in the impact region), and tailed-frog
and Marbled Murrelet (negative trends). Note that in
the WRB the trend for the Marbled Murrelet is one
of improving habitat, while in the impact region, the
opposite is true. For the RR-CONS scenario, the
following rare and sensitive species have habitat
trends that were unchanged at the basinwide scale,
and show positive responses within the impact
region: Cascade frog, western toad, sharptail snake,
western pond turtle, Black Tern, Vesper Sparrow,
Western Meadowlark, Ring-necked Duck, Bald
Eagle, and White-tailed Kite. The following species
exhibit negative trends within the impact region
only: Cascade torrent salamander, tailed frog, long-
legged myotis, fisher, white-footed vole, Marbeled
Murrelet, and Olive-sided Flycatcher.
Finally, the change in habitat scores for the
1850 landscape with respect to 1990 conditions,
show extreme swings in magnitude within the
impact region. Examination of the species response
charts for birds (Appendix A.21) allows comparison
between the trends across species for the 1850
landscape with the trends for RR-CONS. Those
species that respond to the restoration activities of
RR-CONS, also show large responses under the
1850 scenario7 (for example, Vesper Sparrow, Lark
Sparrow, White-tailed Kite, Red-shouldered Hawk,
etc.). This indicates that RR-CONS has, as planned,
turned the trajectory of vegetation change back
toward the 1850 landscape, albeit only to a small
extent. Nevertheless, the increase under RR-CONS
in the rare vegetative communities of 1990, does
have a noticeable effect, at least as viewed by the
habitat evaluation model.
Appendix A.21 also shows enhanced re-
sponses for species favoring more old growth
forests, and shows negative responses for species
favoring development. Additionally, the trend across
����
species for the 1850 scenario, appears to roughlycorrelate inversely to the trend shown for PT-EX.
That is, those species that are declining most under
PT-EX are those that increase most under the 1850
scenario; those that increase most under PT-EX
are those that decrease most in the 1850 land-
scape.
Does restoration improve conditions
for oak and grassland species?
Comparison of the changes in habitat scores
with respect to 1990 conditions shows that scenario
RR-CONS is preferable to all other alternative
futures on the basis of improving habitat for a wide
spectrum of vertebrate species. However, as has
been shown, conditions for some species improve
while declining for others. Since oak and grassland
ecosystems are at risk in the WRB, concern is
-40.0%
-20.0%
0.0%
20.0%
40.0%
60.0%
80.0%
100.0%
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SPECIES RESPONSES TO HABITAT CHANGES � Does restoration improve conditionsfor oak and grassland species?
Fig� ����� Improvement in habitat conditions for oak woodland�savanna�grassland species under theconservation clusters landscape� RR�CONS� compared with the plan trend landscape� PT�EX� in theimpact region� Results outside the shaded box are considered significant� Negative values representbetter conditions under PT�EX; positive values indicate better conditions under the RR�CONS scenario�
mounting over conservation of wildlife and plant
species of these ecosystems.
Vertebrate species named by multiple litera-
ture sources as important to oak woodland, sa-
vanna, and prairie associations were selected
(Appendix A.23). For each species, the habitat
scores for the RR-CONS landscape within the
impact region were compared with those of plan
trend, PT-EX. Significant changes were considered
to be those that exceeded +/-10% of 1990 scores.
This calculation represents the improvement in
habitat conditions for the species within the impact
region if the conservation clusters scenario was
employed.
Fig. 4.22 shows the results with those for the
1850 landscape included to provide context. Of the
31 species, 19 have significantly better habitat
conditions in the RR-CONS landscape. One,
Cassin’s Vireo, is better off under plan trend. Under
��� RESULTS
the 1850 landscape, 20 species have significantly
better habitat, while eight would do better under
plan trend.
Basinwide, similar calculations show that the
RR-CONS landscape provides better habitat
conditions for six species with 25 species unaf-
fected. All other alternative RR futures are no more
beneficial than PT-EX.
���
1. Excluding Yamhill and Columbia counties, there are
approximately 136,100 privately owned taxlots located
outside 1990 UGBs.
2. Lacking a designated upland shrub habitat class in the
land use/land cover or habitat legend, I assumed that
habitat “tree upland/open” was the analog.
3. Calculated as{ sum of all habitat scores in every 1/4
acre cell of the species range in which the score is 5 or
greater} / {total number of these 1/4 acre cells}. Thus for
this species: 10085/2017 = 5.0
4. This species has been evaluated as “extirpated” within
the WRB. However, on four recent occasions, a Lewis’
Woodpecker was sighted in the Mt Pisgah area of Lane
Co. This area is currently undergoing restoration to oak
savanna.
5. Csuti et al. (1997) reports that the pallid and
Townsend’s big-eared bats are both intolerant of distur-
bance. If so it seems unlikely that they would successfully
breed near housing developments. On the other hand, the
PNW-ERC wildlife experts scored built low density as a “3”
on the scale of 1-10, and indicated a benefit from proximity
to built low density habitat (adjacency rule D+).
6. Habitat is considered concentrated if the area of source
habitat (i.e., habitat evaluated by the model as scoring
more than 4) within the impact region is more than 15% of
the species source habitat in the WRB. The impact region
is 12% by area of the WRB.
7. Line up the peaks vertically by species and observe the
correlation.