Modeling the effects of alternative rural residential patterns...

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Chapter Chapter Chapter Chapter Chapter RESULTS RESULTS RESULTS RESULTS RESULTS 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.

Transcript of Modeling the effects of alternative rural residential patterns...

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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.

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��� 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

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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?

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��� RESULTS

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LANDSCAPE PROPERTIES � how many dwellings were sited?

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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

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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

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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?

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�� 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

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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?

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���� 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

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����

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?

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���� RESULTS

Fig

� �

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(a

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����

SNF

ig�

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LU/LC AND HABITAT CHANGES � How is habitat expected to change under current policies?

200

20

Mile

s

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���� 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 ��

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���

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?

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���� 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�

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����

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?

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��� 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�

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���

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?

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���� 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�

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����

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?

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���� 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

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����

(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

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���� 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

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����

(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?

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���� 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�

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����

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

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c ie

s ri

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ess

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ats

of

the

WR

Bfo

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a)

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la

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ttle

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itio

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ose

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the

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p�

SPECIES RESPONSES TO HABITAT CHANGES � How does local species richness change?

200

20

Mile

s

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��� 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

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���

-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)

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���� 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

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����

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

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81-

200

yrs

Con

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clos

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00+

yrs

onife

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atur

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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?

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���� 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

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����

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?

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���� 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-

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���

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?

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���� 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

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����

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%

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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

Page 38: Modeling the effects of alternative rural residential patterns …ise.uoregon.edu/staff/spayne/6_Results.pdf ·  · 2005-03-212050 UGBs 1990 UGBs Valley ecoregion County boundaries

��� 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.

Page 39: Modeling the effects of alternative rural residential patterns …ise.uoregon.edu/staff/spayne/6_Results.pdf ·  · 2005-03-212050 UGBs 1990 UGBs Valley ecoregion County boundaries

���

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.