The Disappearing Landscape
in Eugene’s South Hills
Joyce Chao • Will Green •Joel Grogan • Miranda Schmidt
twoJMW
Project Roles: Executive Summary:
Co-authored by Will Green and Joel Grogan
Conceptual Model:
Joyce Chao
Historical Trajectories Of Change:
Primary author: Miranda Schmidt Assisted by: Will Green
Park Restoration And Management Plan:
Co-authored by Joel Grogan and Joyce Chao
Residential Matrix:
Miranda Schmidt
Green Infrastructure:
Will Green
Layout & Document Organization
Joel Grogan and Miranda Schmidt
Team twoJMW seeks a single grade for this project. LA 441/541 Applied Ecology. Professor Bart Johnson University of Oregon, Department of Landcsape Architecture. Fall 2012
Executive Summary Conceptual Diagram:
Historic Trajectories of Landscape Change Historic Trajectories
Vegetation Change A Tiered Approach Examples of Tiered Landscapes in Eugene Historic Trajectory Conclusion
6
10
11 12 14 15
Restoration & Management of a Neighborhood Park
Introduction 17
Goals 17 Strategies 17
Historic Conditions
Patches and Tiers Speculative Section & Histogram
18
18 19
Existing Conditions
20
Desired Future Conditions (DFCs)
21 22
Recommendations for Management Species
24
Experimental Design
28
Neighborhood Park Conclusion
29
Patches and Tiers Section & Histogram from field data Management & Maintenance DFC Section & Histogram Plant Species Animal Species
Oak Regeneration Experiment
20
Design & Management of the Residential Matrix Introduction 31
Goals 31 Strategies for Success 31 Goal 1: Enhance Oak Savanna 32 Goal 2: Promote Restoration Efforts to Residents 33 Goal 3: Ensure Over Time 34 Existing Conditions: 35 Neighborhood Ecological Audit 35 Recommendations for Management Species in Oak Savanna Habitat 36
Urban Green Infrastructure
Introduction 39 Goals, Objectives, & Strategies Assessment of Existing Conditions
40 41
Property Acquisition
42
Green Infrastructure Conclusion
45
Cooperative Management Realized Oak Savanna
43 44
22 23 26 27 28
Indicators of Success: 29 Measures of Success 29 Conclusion 29
3
Executive Summary This report provides a framework for restoring historic levels of Oak Savanna and Upland Prairie landscape typologies across a variety of spatial scales within the urban fabric of South Hills project area, located in Eugene, Oregon. The south hills of Eugene were once dominated by oak savanna and upland prairie. Much of the oak savanna/upland prairie vegetative structure has become coniferous woodland, mixed forests, or urban infrastructure. Analysis of the historic distribution of oak savanna and the limited oak savanna that remains indicates that Oregon White Oak habitats and Upland Prairie require a disturbance regime to prevent landscape succession. Disturbance regimes have drastically changed since 1851, namely fire suppression in what was previously an intentionally burned landscape - as well as residential development and associated land management practices. These changes have allowed coniferous stands to overwhelm much of the oak savanna’s structural characteristics. The Elliott Hill project site will model a historic Oregon White Oak savanna by the removing and managing Douglas fir (Pseudotsuga menziesii), which will reveal the existing Oregon White Oak trees. Supplementing oak recruitment by planting young oak trees will accelerate the Elliott Hill Oak Savanna restoration. A successful design and management plan for Elliott Hill will provide the basis for continued conservation by becoming an aesthetic and ecological demonstration area, providing a model for oak restoration assessment throughout the Southern Willamette Valley, and by providing important habitat for our management species, Oregon Oak
(Quercus garryana), Upland Grasses (Graminoids), Pocket Gopher (Thomomys bulbivorus), and White�breasted Nuthatch (Sitta carolinensis). On a larger scale, Elliott Hill essentially will become a connecting hub to a network of habitat corridors that will traverse the urban matrix of the Eugene South Hills region. These habitat corridors will take into account and integrate existing human developments, with some key undeveloped areas acquired specifically to become core habitats, utilizing the Elliott Hill design as a starting point. A residential-level plan targets private property owners willing to ecologically enhance their land in at various commitment levels to become a part of the Oak Savanna and/or Upland Prairie landscape. Team twoJMW Goals: 1. Enhance oak savanna and upland prairie quality and quantity. 2. Promote and inspire restoration of these ecosystems for residents of the South Hills Area 3. Ensure long�term success project through to ecological and socioeconomic factors. Key ecological interventions: 1. Elliott hill design and management plan that re-establishes Oak Savanna and Upland Prairie habitats toward historic vegetative structure. 2. Acquisition of key undeveloped properties to become part of the Oak Savanna/Upland prairie network. 3. Public land management that integrates the needs for an ecologically healthy Oak Savanna/Upland Prairie landscape.
Management Species: The selected management species are year-round residents that represent varying degrees of imperilment. These species individual and shared habitat needs promote a balanced approach to oak restoration. • Nuthatch (Sitta carolinensis): All members of this genus nest in holes or crevices. Most species are non‐migratory and live in their habitat year‐round. They prefer Oak trees with dead wood and cavities for foraging and nesting. • Pocket Gopher (Thomomys bulbivorus): Pocket gophers are burrowing rodents. Gophers can collect large hoards of food and disperse seeds. Pocket gophers require open savanna‐like habitats for burrowing and foraging. • Upland grasses (Graminoids): Upland prairies include wet prairies, grassy hillsides, and oak dotted woodland edges. They most often occur in well‐ drained soils that traditionally experienced burning regimes as a result of the Kalapuya Natives. Historically these areas had no more than 33.3% tree cover. • Oregon White Oak (Quercus garryana): Oaks thrive in open savannas with well‐drained soils, but are hardytrees and will stand water and varying soils as well. The emergence of taller conifer species like Douglas-fir (Pseudotsuga menziesii) outcompete Q. garryana for light and lead to eventual death.
Scale
Goals
Strategies
Restore oak savanPark restoration Elliott Hill na/upland prairie plan and community stewardship. Recreation Area habitat.Educate community. Range of intervenEnhance Oak tions based on resiResidential Savanna and pro- dent commitment mote restoration level and tiered Matrix efforts analysis
Green Infrastructure
Increase Oak Savanna and Upland Prairie habitat.
Creation of core habitats and network of corridors.
Summarized Goals and Strategies
Biological integrity & Ecological health: Restoring Biological integrity of the Oregon White Oak Savanna vegetative structure requires integrating all plant and wildlife species that existed pre Euro-American settlement in the Willamette Valley in the 1850’s. The vegetative structure was maintained over millennia with an annual large scale burning disturbance regime conducted by the Kalapuya Indian People. Restoring and integrating ecological processes of the Oregon White Oak Savanna into an urban fabric is the primary emphasis of this report.
5
Conceptual Diagram:
Long Term Approach
Intermediate Term Approach
Short Term Approach
Historic Trajectory: The South Eugene hill was once dominant by oak savannah; however the vegetative structure have changed since 1851 due to the European settlement. The cessation of fire regime caused the drop of oak population and the invasion of Douglas fir.
Goal 1: Bring Oaks Back - Disturbance regime -Thining -Plant new oaks
Restoration & Management of Park
Goal 2: Integration With Urban Matrix -Corridor development -Key acqusition development -Public land management
Goal 3: Promote To neighborhood -Supporting Habitat -Aesthetic & Experiential quality
Green Infrastructure
-Success over time
Design Management of neighborhood Matrix
7
Historic Trajectories Of Landscape Change
Map from Hulse, Gregory, & Baker 2002
9
Historic Trajectories The south hills area of Eugene was once dominated by oak savanna (Figure 1.4). Much of the oak savanna and its vegetative structure has been lost or converted to coniferous woodlands, forests, or urban growth (Figures 1.6 & 1.7). Studying these human disturbances - either from the Kalapuya Indians (pre-European) or current disturbance regimes- it becomes clear that Oregon oak habitat relies upon regular low-intensity disturbances to prevent succession toward fir-dominated forest caused by Douglas fir invasion. Disturbance regimes have drastically changed since 1851, namely the absence of intentional annual burning and the suppression of naturally-induced fires. These activities, re- Figures 1.1 & 1.2: Annual burning by Kalapuya maintained oak savanlated to and in tandem with residential development, have allowed Douglas fir stands to nas for millennia overwhelm much of the oak savanna, eliminating it’s characteristic open structure. The changes in land cover types over the past 150 years since European settlement are primarily due to cessation of the burning regime. In many places, this has allowed Douglas fir forests to begin moving further down into the valley floor. As the firs grow they shade out and eventually kill the white oak, which simply cannot compete for sunlight. Other changes in the last 150 years include increasing urbanization, expressed in roads, utilities, residential and commercial buildings. This has affected the vegetative composition and patterns of the South Hills area as well as the hydrologic systems. With an increase of development, many of the seasonal streams of the area have been channelized or put into underground pipes, simplifying the hydrologic regime. Over time, these hydrologic impacts have reduced ecological integrity. Historic areas of high ecological health have been reduced in size and isolated by housing development and fragmented by roads - which can be hazardous or impassable for many species. Open spaces within the south hills neighborhoods, such as Tugman Park and Elliott Hill (Figure 1.3), provide a snapshot of these historic trajectories because they contain remnant historic oak savanna structure as well as various degrees of succession to woodlands and forest.
Figure 1.3: Tugman Park typifies open spaces in Eugene and how they relate to the historic conditions of the valley.
01: Historic Trajectories
twoJMW 10
Vegetation Change
Historic Trajectories- South Hills, Eugene
Current Trajectories- South Hills, Eugene
1.16% 1.16%
11.48%
27.91%
11.48%
Savanna Upland Prarie Riparian Forest Woodland/ Forest
1.64%
Savanna Upland Prarie Riparian Forest Residential Woodland/ Forest
69.77%
75.41%
Figure 1.4: Historic Vegetation Classification (1851) South Hills, Eugene
Figure 1.5: Current Vegetation Based on Aerial Imagery South Hills, Eugene
Composition of the Vegetation Type (%)
Composition of the Vegetation Type (%)
METHODS: The primary method of historic analysis compared a series of overlaid maps of the South Hills project area comprised of aerial photographs, historic vegetation classifications, and a grid of 380 squares, each 1,000 ft. x 1,000 ft. overlaid on an aerial photo of South Eugene. Each cell in the current aerial image was compared to the same cell in the historic vegetation classification map. RESULTS: Analysis of the Historic Vegetation Classification, indicates Oak Savanna covered 69% of the project area (Figure 1.4). Of this historic Oak Savanna, very little remains. The fates of each historic vegetation classification category are displayed in Figures 1.6 & 1.7. DISCUSSION: Aerial photos indicate that remnants of the oak savanna structure remain – either in unhealthy stands being over run by conifer trees or as small patches of low tree density within the urban matrix. These small patches, consisting of residential parcels and urban parks are categorized as tier 1 and mapped in Figure 1.9. It is clear that Oak savanna structure has suffered due to urban development and forest succession. These histograms provide a useful tool in prioritization of different areas for restoration efforts because historic oak savannas are more likely to be recovered. Vegetation Type
Figure 1.6: Historic Vegetation Classification and Current Vegetation
Vegetation Type
Figure 1.7: Relative Abundance of Historic Vegetation Classification and Current Vegetation 11
A Tiered Approach
Figure 1.8 Historic (1851) Land Cover
Figure 1.9 Tier Analysis based on current aerial imagery
Figure 1.8 shows dominance of oak savanna and upland prairie in the south hills. Historic management by the Kalapuya people consisted of annual burning to maintain plant and animal resources (Boyd, R. 1999 - in Course Reader). This created prime oak savanna habitat. Creating a framework of assessment of savanna restoration potential in the South Hills is crucial for prioritization and classification of future maintenance regimes. These focused efforts will promote an expansion of aesthetically pleasing oak savannas for residents and critical habitat for local savanna species. Elliott is in the heart of the south hills and shows promise as a study area and a potential seed source for oak savanna restoration. We have come up with an Oak Savanna Habitat Assessment for the population of south Eugene to encourage easy oak savanna restoration efforts. Along with creating a completely restored oak savanna park at Elliott Hill, the recreation area will also serve as an oak harvesting spot for proposed restoration. People will be able to look at the historic trajectories of change and apply it to their individual circumstances on their desired lot to then further their maintenance regime and planting plans. The maps shown are important in looking at corridors for the South Hills area and where it is most reasonable to go about restoring oak savannas. 01: Historic Trajectories Figure 1.9 is an assessment of current landscape typologies characterized by a tier system, outtwoJMW lining the potential for oak savanna restoration efforts, as shown in figure 1.10. 12
Present State
Tier One: Open Areas that have experienced similar maintenance regimes over time.
Tier Two: Mixed woodland that show signs of a historic oak savanna, but overcrowding due to poor management is apparent.
Tier Three: Closed woodland forests that show poor signs of oak savanna restoration success and no maintenance regimes
Historic State
Urban Turf
upland prairie, savanna
Parks
upland prairie, savanna, wet prairie
Golf Courses
upland prairie, savanna, wet prairie
Residential
upland prairie, savanna, wet prairie
Parks
upland prairie, savanna, wet prairie
Urban Matrix
upland prairie, savanna, wet prairie
Residential
upland prairie, savanna, closed upland forests, woodland
Parks
upland prairie, savanna, closed upland forests, woodland
Closed Woodland
upland prairie, savanna, closed upland forests, woodland
Figure 1.10: Historic Vegetation Relationship with Oak Savanna Restoration Efforts 13
Examples of Tiered Landscapes in Eugene
Figure 1.11: Front yards just south Figure 1.12: Unmanaged Oaks in Figure 1.13: Oak with residential setting of Elliott Hill exotic shrubs and trees
Figure 1.14: Edge trees in wood- Figure 1.15: Borrowed landscape scenery in views of hills land setting
Figure 1.16: Oakway Center; Old-growth Oak
Figure 1.19: Unmanaged oaks suc- Figure 1.20: Unmanaged Oaks, near mowed grass. ceeded by fir
Figure 1.17: Unmanaged Oak suc- Figure 1.18: Oak tree in a park ceeded by fir on upland hill
The open-crown growth habit of the oak tree is an important factor in the restoration of oak savannas. Large and open-crowned oaks in the Willamette Valley have been shaped by fire and other harsh conditions over time. Old growth oak trees (100 years or greater) can bee seen around all around Eugene. These trees are found in parks, residential neighborhoods, commercial development, and some represent aesthetic value and landscape time such as the old-growth oaks in Oakway Center shown in Figure 1.16. Most of the oaks today, however, are slowly under succession impact by firs such as the oak trees in figures 1.12, 1.14, 1.15, 1.17, 1.19 and 1.20. 01: Historic Trajectories
twoJMW 14
Figure 1.21: 1936 Aerial
Figure 1.22: 2012 Aerial
Historic Trajectory Conclusion Team twoJMW goals include restoring oak savanna in Elliott Hill recreation area and identifying the remnants of oak savanna within the current urban matrix. Remnants of oak savanna found could be converted into habitat corridors linking Elliott Hill area to other healthy remnants of oak savanna with the long term goals of enhancing the oak savanna across the urban matrix. A successful design and management
plan for Elliott Hill will provide the basis for continued conservation by becoming an aesthetic and ecological demonstration area, assisting with oak restoration assessments throughout the south hills by providing oaks at different stages in life for transplanting, as well as a habitat core for several species that reside in this vegetative structure.
15
Restoration & Management of a Neighborhood Park
Introduction
This section analyzes historic and existing conditions at Elliottt Hill Park and proposes desired future conditions (DFCs) based on these factors. We have also proposed specific interventions for all four management species and designed an oak regeneration experiment.
Goals
1. Enhance and restore remnant Oak Savanna and Upland Prairie at Elliottt Hill 2. Make Elliott Hill a demonstration of aesthetic beauty and ecological health for the neighborhood 3. Sustain and expand ecological and social value of the park over time
Strategies
1. Develop a restoration plan based on historic conditions and DFCs • Implement targeted restoration and maintenance efforts to achieve DFCs for each management unit 2. Promote neighborhood appreciation and stewardship of park restoration 3. Use management units and DFCs to maintain trajectory toward historic vegetative structure 17
Historic Conditions The historic conditions of Elliott Hill Park are mostly consistent with the historic vegetation classification of the entire south hills project area. One difference noted at this finer grain of vegetation classification is that the 1851 data classifies the majority of the park as ‘White Oak-Black Oak-Ponderosa Pine Savanna’. The only exception is Patch A, which is classified as ‘Upland Prairie’. While Current Patches A & C (are structurally similar to the historic conditions, the rest of the park has become much more densely vegetated - likely a result of the cessation of burning.
Patches and Tiers
Patch B: Oak/Pine Savanna
Patch A: Upland Prairie
Figure 2.1- Historic (1851) Conditions from Vegetation Classification
Figure 2.6 shows the historical vegetative structure of Elliott Hill in 1851. Oak was once a dominant species that thrive d throughout the site. Other vegetation was managed under natural disturbance regimes, such as seasonal fire. The fire regime provided an important ecological role of suppressing undergrowth. Mature Q. garryana are fire tolerant trees, while shrubs and young fir trees are highly flammable. The fire also created a more open landscape which allowed Q. garryana to stretch out the branches and reach the sunlight. In addition, upland prairies are good complementary to the oak to maintain a healthy oak woodland. Some snags and sapling firs could also be found in the oak woodland, they are the evidence of management regimes. Oaks are more tolerant to different type of soil and solar condition than conifers that found on site. According to the historic trajectory, higher density of trees are found on hillside.
02: Park Restoration
twoJMW 18
Figure 2.2* - Indian burial site in Willamette Valley
Referenced Q. Garryana Species Report and Plant Community Structure notes
Figure 2.3* - Willamette Valley agricultural landscape
Figure 2.4* - Downtown Eugene facing Skinner Butte *Figs 2.2-2.4 from Lane County Historic Society
6
5
4 QUEGAR
3
PINPON QUEKEL
2
1
0 000 ‐ 5
006 ‐ 25
026 ‐ 50
051 ‐ 75
076 ‐ 100
101 ‐ 125
125+
Figure 2.5 - Speculative Historic Tree Histogram for Elliott Hill Park, based on historic vegetation classification
Speculative Section & Histogram
Tier 1 Tier 1 Oak Savannah Oak Savannah (Naturally Managed) (Kalapuya Managed) The transect shows the historical vegetative structure of Elliot Hill in 1851. By the time, the park was managed under nautural disturbances regimes. Fire regime specifically provides an
Figure 2.6ecological - Speculative Section showing relative abundance important process for Oaks (Quecrucs garryana) to thrive and distribution of oaks and pines at Elliott Hill Park.
19
Existing Conditions Existing conditions are assessed here via the tier system outlined in Historic Trajectories of Change. The tiers have driven the identification of 4 main patches (A-D) which will require different management strategies to achieve the desired future conditions. METHODS: Student teams collected data at the site by establishing 8.9m radius plots. Teams collected plot data such as aspect as well as vegetation data at the ground, shrub, and canopy tree level. Trees were individually recorded by species and DBH.
Patches and Tiers
Patch C: T1 Patch B: T2
Figure 2.8 - Student team collecting data in Patch C.
Patch D: T3
Patch A: T1
Figure 2.7- Existing Conditions - Patches & Tiers
Patches A and C are both Tier 1 landscapes which represent relatively intact oak savanna. Patch B, a mixed woodland with remnant oak trees show an intermediate level of invasion by Douglas firs, typifies Tier 2 landscapes. Patch D is in Tier 3, with the largest and most dense fir trees on the site with few to zero remnant oaks. Given that the entire site was once covered in oak savanna, the physical and spatial characteristics of vegetation that define this area today tell a story of management practices and their effects. The tier 1 areas have been maintained under a mowing regime, likely to reduce fire danger and promote open views from adjacent residents. Patch B, the tier 2 area, has probably been thinned periodically, also to reduce fire danger. This has delayed the onslaught of Douglas fir encroachment. Patch D, where the conifers are largest and most established covers the steepest slopes on the site, and includes the crest of the hill. Thinner soils in these areas likely play a role in the increased dominance of fir and pines. The age of these trees suggests that some conifers occurred here even when the land was under the management of Kalapuya Indians. GIS data provided to our class also supports this notion, with an 1851 vegetation survey classifying much of this area ‘White Oak - Black Oak - Ponderosa Pine Savanna’ 02: Park Restoration
twoJMW
Figure 2.9 - Student team walking through NW section of Patch B.
Figure 2.10- Photograph taken from Patch C facing Toward Patch D.
Tree Species and DBH class per acre ‐ Patch B WOODLAND 140 120 100 80
QUEGAR PSEMEN
60
PRUAVI
40 20 0 000 ‐ 5
(Well Managed)
026 ‐ 50
051 ‐ 75
076 ‐ 100
101 ‐ 125
125+
Figure 2.11 - Tree Histogram for a sample plot in Patch B generated from data collected by student team.
Section & Histogram from field data
Tier 1 Oak Savannah Tier 1 (Well Managed) Oak Savannah
006 ‐ 25
Tier 2 Mixed Woodland Tier 2 (Managed) Mixed Woodland (Managed)
Figure 2.12 - Diagrammatic Section showing existing conditions at Elliott Hill Park.
Tier 3 Conifer Woodland Tier 3 (Poorly Managed) Conifer Woodland (Poorly Managed)
Tier 1 Oak Savannah Tier 1 (WellUpland Managed) Prarie (Well Managed)
The section shows the existing condition of Elliot Hill. The current condition indicates that the historic oak savannah is decreasing, and the site is tend to dominanted by conifers, such as Douglas-fir (Psudotsuga menziesii).
21
Desired Future Conditions (DFCs) Our DFCs for Elliott Hill Park reflect both historic trajectories as well as current conditions . While Patch A contains a mix of struggling oaks and young Douglas firs, Patch B is dominated by evergreens, including several remnant Ponderosa Pines. Based on these conditions we propose Patch A be completely restored to Oak Savanna Structure while Patch B be restored to a mixed evergreen/deciduous woodland (Figure 2.13). We propose a site assessment followed by thinning and continued monitoring and maintenance.
Management & Maintenance
Patch A: Savanna T1
Figure 2.14- Example of overgrown patch of remnant oak savanna
Patch B: Woodland
Figure 2.13- Desired Future Conditions at Elliott Hill Park
In order to transition existing conditions to DFCs the following steps would be taken: • Site assessment of all tree species present on the site and their DBH • Marking of all nonnative trees and all Douglas Firs under 100cm DBH (Figure 2.14) • Removal of all marked trees (Figure 2.15) • Assessment of understory species present • Removal of nonnative understory species • Continued monitoring via site assessment (tree species and DBH, understory species and cover classes) • Continued maintenance by mowing and hand removal to prevent growth of young Douglas firs and nonnative understory (Figure 2.16) • Supplemental planting of acorns and young oaks to hasten oak recruitment
02: Park Restoration
twoJMW 22
Referenced Morrison, D. 1987
Figure 2.15- Example of same area immediately after thinning
Figure 2.16- Example of same area several years after thinning.
3.5 3 2.5 QUEGAR
2
PINPON QUEKEL
1.5
PSEMEN 1 0.5
DFC Section & Histogram
0 000 ‐ 5
006 ‐ 25
026 ‐ 50
051 ‐ 75
076 ‐ 100
101 ‐ 125
125+
Figure 2.17 - Tree Histogram for DFC in Patch B (Woodland)
Tier 1 Oak Savannah (Well Managed)
Tier 1 Oak Savanna (Well Managed)
Tier 1 Oak +Pine Savannah (Well Managed)
Figure 2.18 - Diagrammatic Section illustrating DFCs in Elliott Hill Park
Tier 1 Oak +Pine Savanna (Well Managed)
Tier 2 Oak Savannah (Managed)
Tier 2 Oak Savanna (Managed)
Tier 1 Oak Savannah (Well Managed)
Tier 1 Oak +Pine Savanna (Well Managed)
23
Specific Recommendations for Management Species
Oregon White Oak (Quercus garryana)
White Breasted Nuthatch (Sitta carolinensis)
Upland Prarie (Graminoid)
Camas Pocket Gopher (Thomomys bulbivorus)
02: Park Restoration
twoJMW 24
Preferred Habitat
Nest Requirement
Oregon White Oak
Oak Savannah Woodland
Tolerate to many soil Open ground
Upland Prarie
Moderately moist soil, Grassy area
Quercus garryana
Graminoids
Camas Pocket Gopher
Thomomys bulbivorus
White Breasted Nuthatch Sitta carolinensis
Status within the Willamette Valley
Reason For Decline
Decline
Year round resident
Human compression to natural fire
Declining 70% of oaks since 1851
Full sun partial shade Open ground Tolerate dry
Year round resident
Human compression to natural fire
Decline in population and increase in fragmentation
Underground Burrow
Year round resident
Grassland Upland Prarie
Open Oak Woodland Residential Areas
Old growth tree with cavities
Habitat Degradation
Year round resident
Population is stable
Urbanization
Habitat Degradation Loss of Oaks
Declining approximately 10 % per year
Figure 2.19 - Table of Management Speices
25
Plant Species Oregon White Oak: Conifers like Douglas Fir suppress the growth of Oregon White Oaks and have caused severe decline in Oak population. In order to promote healthy oak population at Elliott hill, we propose removal smaller Douglas-firs, while retaining larger specimens for snags and habitat value (Figure 2.17) We propose complete removal of other invasive species, such as Mazzard Cherry (Prunus avium) and the Himalayan blackberry (Rubus armeniacus). Ponderosa Pines will also remain with the Oaks to maximize the structural experience of historic conditions. In addition, new acorns and saplings will supplement natural recruitment. Upland Prairies: After Euro-American settlement in the 1830s, regular burning of prairies ceased. This facilitated invasion by native and non-native understory species and grasses. As a result, native upland prairies, along with wetland prairies, now cover much less than 1% of their former area. The decline in upland prairies and their increased fragmentation has led to the decline of many native prairie plants and animals. The upland grasses prefers full sun to partial shade, relatively open ground, and tolerate dry to wet soil conditions.
02: Park Restoration
twoJMW 26
Tie Oak Sa Referenced Student Species Reports (Well Ma
er 1 avannah anaged)
Animal Species White Breasted nuthatch: The nuthatch is most likely to be found in open Oak savannah or woodland in the Willamette Valley. However, due to the destruction of habitat and lack of large diameter of oak trees with cavity formation, the nuthatch population is in decline. In the restoration plan, the proposed oak savannah will provide suitable old growth oaks with spreading crown and cavities to inhabit. The retaining of snags will also be the complementary to oaks and provide nesting opportunities for nuthatch.
Figure 2.20 - Diagrammatic Section illustrating species-specific recommendations
Camas Pocket Gopher: The pocket gophers are herbivores that occupy both above ground and underground areas. They tend to prefer roots of native forbs, but will eat nearly any type of plant roots they come across including grasses, shrubs, seedlings and nuts. Therefore the upland prairie grasses and oak acorns will offer plentiful food resource to the pocket gopher. The oak savannah provides them wide subterranean space to excavate and tunnel away from urban and traffic danger. Pocket gophers are good natural soil engineers; in the process of excavating, the soil is flipped and well-mixed. Thus, pocket gophers provide important benefits to the soil structure and aeration of the oak savannah.
27
Experimental Design Oak Regeneration Experiment PROBLEM: Lack of oak regeneration at Elliott Hill Park HYPOTHESES Ho: Thinning of Douglas fir at Elliott Hill will have an effect on native oak recruitment. Ha: Thinning of Douglas fir at Elliott hill will have no effect on native oak recruitment. EXPERIMENTAL TREATMENT Each of 3 replicates will consist of two adjacent 10m x 10m plots for a total of 6 plots. Control Treatment #1 Treatment #2 0% Removal X 50% Removal X 100 % Removal X SAMPLING PROTOCOL For the purposes of this experiment, regeneration will be measured in number of live native oak stems per plot. Three 1m quadrats will be randomly selected within each test plot. Surveys recording live woody stems per each 1m quadrat will be conducted in the fall before leaf drop. Quantities of live stems by species will be compared to determine relative abundance of young trees.
REPLICATION OF TREATMENTS & CONTROLS Test plots established in experimental design will remain consistent for the duration of the experiment for consistent replication of results. Location of test plot margins should be no more than 100’ from a mature native oak. Test plots that either contain or are within 100 feet from a mature oak will limit bias due to limits of acorn dispersal. PLAN FOR RANDOMIZATION/STRATIFICATION Once test plots have been selected, treatments will be randomly assigned to each plot. Each test plot will then be divided into 1m x 1m plots. Three 1m x 1m quadrats will be chosen from the random number generator to determine which 3 quadrats will be sampled. METHODS OF ANALYSIS After 5 years of sampling, data will be compiled and statistically analyzed to test the null and alternative hypotheses. Relative abundance of oak stems for each treatment will be compared against the control plots. Results will be ranked to indicate which treatments, if any, result in the greatest change in oak recruitment. After completing the statistical analyses, researchers should consider potential bias and lurking or uncontrolled variables. One of the most important variables to consider is the quantity of viable acorns falling from the native oaks. Individual oak trees with high or low relative reproductive success could skew the results. Supplemental or subsequent research on quantity of viable acorn drop within the Elliott Hill Park could help control for this variable. Identification of variability in proportion of viable acorns to total acorns could also reduce opportunities for bias.
02: Park Restoration
twoJMW 28
Class Exercise Reading
Neighborhood Park Conclusion Indicators of Success:
• Quantitative measure of vegetative change • Qualitative measures of utilization by management species and stewardship by neighborhood residents.
Measures of Success
• Quantitative measures for vegetation: DFCs in Figure 2.17 indicate a successful outcome for tree species and DBH class for park restoration efforts. Assessment of shrub and ground layer vegetation in cover classes will provide baseline data for comparison against future conditions. Any reduction on non-native invasive species and/ or an increase in native species at the ground or understory level will be evidence of incremental success. • Qualitative measures for use of Elliottt Hill Park will consist of documented observations by neighborhood volunteers. Baseline data will be collected for at least one breeding season prior to any alteration of existing site conditions. Volunteers will be asked to record data and photograph presence (sightings) of management species within a .25 mile radius of the park. Future data will be compared against this baseline data. An increase in observations is evidence of success. Simple guidelines for observation and data collection will be developed to minimize bias in volunteer-collected results.
Conclusion
Elliottt Hill Park presents a microcosm of the state of oak savanna and upland prairie across the Willamette Valley – both in its ecological state as well as its context within the urban matrix. The opportunity to use this park as a living example of savanna restoration – while a neighborhood watches on– is invaluable. The Neighborhood Park component provides guidance to reveal the historic savanna landscape that is struggling to survive at Elliott Hill- by reducing competition from Douglas Firs and mimicking historic disturbance regimes. Though restoration success at the park-scale is important, long-term sustainability of these efforts depend on the continued support of neighborhood residents. The residential matrix component that follows describes how our work at Elliottt Hill Park will inspire residents to begin to transform their yards into mini-ecological restoration sites.
29
Design & Management of the Residential Matrix
Introduction
This section discusses the application of these project goals and objective to the neighborhood residential matrix on the local scale surrounding Elliott Hill. At this scale, the goal and objectives are defined as follows:
Goals 1. Enhance Oak Savanna and open space. 2. Promote the social value of restoration efforts to residents of South Hills 3. Ensure continued success over time
Strategies for Success
1. Assess the potential for oak savanna restoration through: • Tiered analysis of present and historical vegetation composition residential properties • Facilitate property owner’s choice of restoration level (acorn, sapling, or oak tree) 2. Create solutions based on the vegetation assessment. • Apply these solutions in landscape time by creating five-year, ten-year, and twenty-five year goals based on property owner’s restoration level. 3. Provide design solutions for resident’s particular set of constraints and opportunities toward an oak savanna.
31
Goal 1: Enhance Oak Savanna Enhancing the oak savanna in the South Hills starts with Elliott Hill and the neighborhood surrounding the site. This neighborhood scale is approximately 2.25 miles in diameter and from the middle of Elliott Hill, 1.125 miles in radius. This study area was chosen because it was historically oak savanna. As seen in the Figure 3.1, open patches in the neighborhood are examined as possible corridors for species as well as large, old-growth oaks that are of importance. Historic Veg.
Old-growth Oak Open areas/ potential corridors Project Area
Savanna Upland Prairie Wet Prairie
N
Figure 3.2- Neighborhood oak of importance- Old Growth (60-70 feet ~150 years)
Elliott Hill open patches- direct
about one mile 0
500
1,000
1,500
2,000
Figure 3.1- Neighborhood scale project area- about one mile radius
Indicator of Success- Assess vegetation on Elliott Hill and manage it by removing encroaching firs and other conifers
Figure 3.3- Existing patch Example in neighborhood
creating snags, planting oak trees, native grasses and ponderosa pine. This also pays attention to diversity in age classes for oak trees. Oak trees that are existing and have expansive crowns are paid special attention to. In areas of interest, firs overrunning oaks must be cut down and new trees added to enhance the oak savanna. Vegetation not only has a lot to contribute to the restoration of oak savanna on the neighborhood scale, but also in the regional scale in creating corridors and open patches in the South Hills of Eugene. Performance Standard- In 10 years, increase Oak Savanna in the set neighborhood bya.) In areas of high intervention and oak regeneration focus, 60 % kill of Douglas fir encroachment. b.) Thinning of the oaks for an “open form� that are 10-15 feet tall by 60%. c.) Increase acorn collection and seedling care by 30%. d.) Decrease invasive exotics (Himalayan blackberry, Prunus avium, non- Figure 3.4- Ideal oak savanna aes03: Residential Matrix native grasses) by 60%. thetic on private residential prop-
twoJMW
32
erty
Goal 2: Promote Restoration Efforts to Residents Enhancing the oak savanna in the south hills will require participation from residents in the south hills. In order to promote participation, it is responsible to accommodate people’s needs, interests, and constraints. Not everyone wants an extensive oak savanna in their front yard, instead creating a tiered assessment of the resident’s comfort level of intervention within their vegetative composition tier. From smallest intervention impact (acorn) to a fair amount of intervention (sapling) to the most amount of intervention impact (oak tree), residents have an option to pick which level suits their needs the most. This will then help to increase the participation in residents to do some amount of work to help the restoration efforts of the oak savanna.
Indicators of Success- 1. Looking at the tier analysis map and historic trajectories map, it is then determined which tier the resident stands in (one,
two, or three). 2. Commitment level the resident has in going through change. Asking the resident how they feel about intervention can help keep this about the residents’ interest. It all depends on their interests and aesthetic aspirations. Performance Standard- Increase participation within the neighborhood by 50% within 10 years; increase participation within the South Hills, Eugene local scale by 50% within 25 years. Tier Analysis based on Vegetation Tier One: Open Areas that have experienced similar maintenance regimes over time. Tier Two: Mixed woodland that show signs of a historic oak savanna, but the overcrowdedness of unmanaged savannas are apparent. Tier Three: Closed woodland forests that show poor signs of oak savanna restoration success and no maintenance regimes
Commitment Level of Intervention ACORN SAPLING OAK TREE
ACORN SAPLING OAK TREE
ACORN SAPLING OAK TREE
Example Intervention Strategies The least amount of restoration work done to the most healthy oak savanna habitat tier. Residents may just want to adjust their management schedule overtime to ensure no firs take over. A fair amount of intervention to an already ample oak savanna habitat. May need to create a snag, plant native grasses, and add a couple oaks. A large amount of restoration attention to an open and maintained property. This yard is reaching for the most ecological health and integrity A resident with potential of much oak habitat, but has little motivation for much change. May keep most of the firs, but get rid of the ones crowding the oaks. A fair amount of intervention. Ensure existing oaks and added oak are in open area, native grasses present, no crowded oaks, and a snag. Time line. A large amount of restoration attention to vegetative structure and maintenance regime. This yard is reaching for the most ecological health and integrity. A resident that enjoys a closed vegetative yard, but may want to pay attention to the existing oaks. This does little to the expansion of oak savanna and corridors. A fair amount of intervention to a heavy woodland forest. May need to create a snag, address the crowded oaks by getting rid of conifers, and add oaks. A large amount of restoration attention to a difficult woodland vegetative structure. This will take most time to get the composition to the desired savanna habitat and special attention to how the ecological health and integrity changes over time.
33
Goal 3: Ensure Over Time
Figure 3.5- Example of a House in the neighborhood that shows potential for time line assessing
As a resident of this neighborhood, one might find it useful to ensure a project time line specific to their tier and comfort level. Figure 7 shows a conceptual time line that shows graphically what it may look like as well as a set of performance standards to abide by. This strategy is successful in that it addresses landscape time, historic vegetation, and current vegetation structure. Indicators of Success- Measure the success and process of the oak restoration efforts of: • Oak trees • Native Grasses • Native species count • Management • Snags
Figure 3.6- Spencer’s butte in the back- Applying landscape time and envisioning views and open space.
- Assess Oaks and other oak savanna vegetation (such as ponderosa pine) - Keep young oaks - Increase open space by 30% - Kill off Douglas fir by 30% - Create sapling for birds - Plant more oaks (13-14 per acre)
Performance Standard- Performance assessment of oak savannas for residents
whom undergo change. A maintenance regime is required to follow year after year. Making assessments and goals for a property in 5 years, 10 years, 25 years, and 100 years is necessary in order to ensure that over time, the restoration efforts will be supported.
- In areas of high intervention and oak regeneration focus, 60 % kill. - Thinning of the oaks for an “open form” that are 10-15 feet tall by 60%. -Increase acorn collection and seedling care by 30%. -Decrease invasive exotics (Himalayan blackberry, Prunus avium, nonnative grasses) by 60%
5 years
- Address maintenance regime and how it has been successful over timeapply it to other projects. - Keep young oaks, old oaks - Kill off Douglas fir by 90% - Plant more oaks (13-14 per acre) -Decrease invasive exotics (Himalayan blackberry, Prunus avium, nonnative grasses) by 90%
10 years Figure 7- Example Project Time line with process assessment
03: Residential Matrix
twoJMW 34
25 years
- Canopy Oak cover must exceed Douglas fir canopy cover. -Mimic Historic vegetation structure - Address maintenance regime and how it has been successful over time and apply it to other projects.
100 years
Existing Conditions: Neighborhood Ecological Audit Enhancing the oak savanna in the South Hills starts with Elliott Hill and the neighborhood surrounding the site (Figure 7). For the neighborhood ecological audit, I have chose these two houses because they each represent a separate historic habitat type- upland prairie and oak savanna. Both of these properties also show elements from the historic vegetation types. Considering space, vegetation structure, habitat elements, hydrology, and management species, recommendations are made to the two properties (Figures 3.8 & 3.9)
Figure 3.7- Residential Matrix Design Strategy
Recommendations for Oregon Oak Savanna Keep red oak in front. Take out firs in the backside of the property. Create snag for habitat.
Figure 3.8- Existing house in historic Upland Prairie
Replace exotic ornamental shrubs with native shrubs such as Vaccinium ovatum Adjust maintenance regime. Replace turf with native grasses and cut grasses seasonally. Take out firs in the backside of the property. Create snag for habitat. Keep historic oak. Analyze age of birch tree- may replace with ponderosa pine or another oak. Expand native grass collection Replace exotic ornamental shrubs with native shrubs such as Vaccinium ovatum
Figure 3.9- Existing house in historic oak savanna
Example Category of Commitment Level for Residential Participation Intervention TIER ONE Continued maintenance mowing regime, southwest-facing, one red oak, open space, exotic species, slight slope for drainage.
TIER TWO Mixed woodlandbirch tree, Douglas Fir, Yews, etc., existing historic Oregon Oaks, some maintenance regime, north-facing
ACORN SAPLING OAK TREE
ACORN SAPLING OAK TREE 35
Residential Design Recommendations for Management Species in Oak Savanna Habitat White-breasted Nuthatch: Design & Management Strategy Supplemental Diagrams
Pocket Gopher: Design & Management Strategy Supplemental Diagrams
Onion PROPOSED One Douglas fir removed, the other top-cut to create a snag. Dying tree left in place rather than removed. Small trees are young oaks that will not reach maturity until the large oak is in decline. Figure 3.10- Residential Design recommendations for accommodating
EXISTING Douglas fir trees will outcompete native oak. A dying tree was removed and replaced with an ornamental pear tree.
White-breasted nuthatch habitat.
Carrot
Parsnip
Oak tree Well-drained Soil
Pocket gopher’s habitat’s are well suited in agriculture land. If a resident doesn’t care for different vegetables such as parsnips, onion, and carrot, the pocket gophers will enjoy these foods in well-fertilized, non-compacted, organic soil. They also benefit the oak in planting the acorns in the ground for sprouting and generating healthy soil for the oak. Figure 3.11- Residential Design recommendations for accommodating Pocket Gopher habitat.
03: Residential Matrix
twoJMW 36
From Student Species Reports
Residential Matrix Conclusion This component suggests goals and solutions for improving the Oak Habitat in the South Eugene Hills neighborhoods, but it also raises important questions about priority. Participation of residents of this area are critical in achieving restoration goals. Within the goals and strategies, residents can find many options for both low-level high-level intervention to increase the oak savanna. Through measures of success, residents will want to improve their property to incorporate elements of historic oak savanna structure. Open space and ecological health with and improvement in the biological integrity of the valley are all traits of an oak savanna. The examples shown in commitment level diagram on page 33 show insight to the process of implementing a plan to restore an oak savanna specific to the resident’s needs and property characteristics. It is also important to know the benefits and constraints of landscape time. Creating a 5-year, 10-year, 25-year, and 100-year time line will ensure that the restoration efforts will meet a desired set of standards that should not be ignored. By identifying a set of goals and strategies for the residential matrix, a series of indicators and performance standards are set in place to ensure, promote, and enhance the oak savanna. Critical components include participation of the residents and adaptive management of indicators and performance standards to ensure the process of restoration reaches it’s full potential.
37
Urban Green Infrastructure
Introduction This section provides regional level analysis and makes recommendations for improving the Oak Savanna and Upland Prairie vegetative structure across the South Hills project area, covering approximately 13.6 square miles. Considerations include the development of habitat corridors, island habitat patches, and other core areas that should be restored and managed to expand the functionality of the Oak Savanna as well as to enhance landscape aesthetics. Primary emphasis is placed on connecting areas of relatively higher ecological function.
This component draws from principles outlined in Dramstad, W.Z. Olson, J.D. and Forman, R.T.T. 1986 39
Goals, Objectives, & Strategies Goal: Rehabilitate oak savanna and upland prairie habitats in the south Eugene Hills area and restore a pervasive oak savanna aesthetic that moves toward historic levels. Strategies for Success: • Thinning of Douglas Fir (Pseudotsuga menziesii) in public areas that are taking over the remaining Oak Savanna remnants and use seasonal mowing to mimic disturbance regimes to manage the understory layer. Augment these areas by planting Oregon White Oak (Figure 4.1) • Recommend public acquisition of areas needed to connect core Oak Savanna Habitats and create corridors. Replicate oak savanna habitat in these areas utilizing the design framework from the Elliott Hill Park design to create a network of healthy oak savanna and upland prairie landscape islands (Figure 4.2). • Partner with property owners and developers to encourage an increase of oak savanna structure by recommending strategies outlined in the residential matrix section and by layering the current conditions vegetative analysis (Figure 4.4). Priority areas classified as Tier 1 will be recommended for Oak Savanna Restoration, while areas classified in Tiers 2 and 3 will be recommended to become mixed woodland by implementing a thinning regime. Specific emphasis will target properties within potential corridor zones (Figures 4.8 & 4.9) as well as areas bordering core habitat lands. In time the increased ecological function of these zones will enhance the continuity between the oak habitat and upland prairie core areas. Areas between core habitat areas as well as buffering properties surrounding them are the main emphasis (Figure 4.3).
Figure 4.1 - Differences in tree form - oak canopy restricted by adjacent firs
Figure 4.2- Mt. Pisgah Arboretum could be connected through corridors
Methods: Green infrastructure planning was based on tax lot analysis • Recommendations for acquisition of undeveloped private property for developing important habitat cores and corridors for Oak Savanna. • Targeting of areas between and around tax lots recommended for acquisition and public lands to identify key areas needed for cooperative corridor development and management for successful Oak Savanna integration. 04: Urban Green Infrastructure
twoJMW 40
Figure 4.3- Oak tree within utility infrastructure along residential road
Assessment of Existing Conditions
Elliott Hill
Present vegetative assessment: The south Eugene hills have evolved from oak savanna to a convoluted matrix of residential woodland and highly developed human dwelling and commercial areas. These developed areas include a wide range of exotic plant species that only take into account site-scale aesthetics and maintenance regimes that are very different from the historic ecological vegetative vernacular. Existing remnants of the historic oak savanna do remain; however, these areas are severely threatened by succession of Douglas-Fir (Pseudotsuga menziesii) and continued urban sprawl that relies on quick-growing exotic tree species. Without a management that utilizes various methodologies across the regional scale – a framework of implementation of management and design plans to restore and rehabilitate the Oak Savanna landscape- the remaining oak savanna habitats will simply disappear.
Figure 4.4- Tier Analysis of South Eugene Area 41
A
B
C
D
E
F
G
H
J
K
L
M
N
P
Q
R
S
T
U
1 2 3 4 5
Property Acquisition6 7
The green indicates undeveloped areas to be acquired. Determining factors include prox-8 imity to current public lands (blue) large areas to add to existing public lands and areas inbe-9 tween to become island habitat cores to poten10 tially become part of and interlinking system of Oak Savanna habitat cores. Red areas are11 heavily commercial areas.
Elliott Hill
12 13 14
Public Land
15
Commercial
16
Residential
17
Agriculture
19 20
04: Urban Green Infrastructure
twoJMW 42
1,000 ft
1,000 ft
18
Figure 4.5- Property Acquisition plan based on Tax Lot Analysis
NORTH
Parcels for Acquisition
Cooperative Management The orange indicates prime areas of public/private management areas. These areas become corridor zones, which fill in the gaps between core public parcels. These areas will utilize rehabilitation standards outlined in the residential matrix chapter.
Elliott Hill
Public Land
Figure 4.7- Cooperative management of residential lots to create buffer zones around core habitats
Commercial Residential Agriculture Parcels for Acquisition Parcels for Cooperative Figure 4.6 -High Priority Areas for Cooperative Management based on Tax Lot Analysis Figure 4.8- Cooperative management for corridor connectivity - note Public Land (purple) in lower left 43
Potential Oak Savanna
Realized Oak Savanna Potential future realized matrix of Oak Savanna coverage within the South Eugene hills that combines public lands, corridors areas, and acquisition areas together. The matrix covers a sizable area of the South Eugene Hills and connects to areas outside of the urban growth boundary.
Elliott Hill
Habitat outside Urban Growth Boundary (UGB)
04: Urban Green Infrastructure
twoJMW 44
Figure 4.9- Green indicates potential for realized oak savanna and connectivity beyond the UGB
Green Infrastructure Conclusion As the public becomes more aware of the presence and ecological benefits of native white oak savanna and upland prairie habitats over time, a unifying vegetative aesthetic will be re-established in the Eugene South Hills area.
45
References: Boyd, R. 1999. Strategies of Indian burning in the Willamette Valley. Pages 94-138 in, R. Boyd, editor, Indians, fire and the land in the Pacific Northwest. Oregon State University Press, Corvallis, Oregon,USA. Dramstad, W.E., J.D. Olson and R.T.T. Forman. 1996. Landscape ecology principles in landscapearchitecture and land-use planning. Washington, D.C.: Island Press. Hulse, David, Stan Gregory, and Joan P. Baker. Willamette River Basin Planning Atlas: Trajectories of Environmental and Ecological Change. Corvallis, OR: Oregon State UP, 2002. p27. Print. Morrison, D. 1987. Landscape restoration in response to previous disturbance. In, M.G. Turner, ed.,Landscape heteroge neity and disturbance, p. 159-172. New York: Springer-Verlag The Society for Ecological Restoration (SER) Primer on Ecological Restoration and the SER Guidelines for Ecological Restoration<http://www.ser.org/reading_resources.asp> Student Species Projects: Chao, Yun. 2012 Camas Pocket Gopher Species Project Grogan, Joel. 2012 White Breasted Nuthatch Species Project Stuart, Fraser. 2012 Oregon White Oak Species Project Field, Tristan. 2012 Upland Prairie Species Project Class Materials: Plant Community Structure Notes Experimental Design Guidelines
Index of Figures
Figure 1.3: Tugman Park typifies open spaces in Eugene 10 Figures 1.1 & 1.2: Annual burning by Kalapuya maintained oak savannas for millennia 10 Figure 1.4: Historic Vegetation Classification (1851) 11 Figure 1.6: Historic Vegetation Classification and Current Vegetation 11 Figure 1.5: Current Vegetation Based on Aerial Imagery South Hills, Eugene 11 Figure 1.7: Relative Abundance of Historic Vegetation Classification and Current Vegetation 11 Figure 1.8 Historic (1851) Land Cover 12 Figure 1.9 Tier Analysis based on current aerial imagery 12 Figure 1.10: Historic Vegetation Relationship with Oak Savanna Restoration Efforts 13 Figure 1.11: Front yards just south of Elliott Hill 14 Figure 1.16: Oakway Center; 14 Old-growth Oak 14 Figure 1.12: Unmanaged Oaks in residential setting 14 Figure 1.17: Unmanaged Oak succeeded by fir on upland hill 14 Figure 1.13: Oak with 14 Figure 1.18: Oak tree in a park 14 Figure 1.14: Edge trees in woodland setting 14 Figure 1.19: Unmanaged oaks succeeded by fir 14 Figure 1.15: Borrowed landscape scenery in views of hills 14 Figure 1.20: Unmanaged Oaks, near mowed grass. 14 Figure 2.1- Historic (1851) Conditions from Vegetation Classification 18 Referenced Q. Garryana Species Report and Plant Community Structure notes 18 Figure 2.2* - Indian burial site in Willamette Valley 18 Figure 2.3* - Willamette Valley agricultural landscape 18 Figure 2.4* - Downtown Eugene facing Skinner Butte 18 Figure 2.6 - Speculative Section showing relative abundance of oaks and pines at Elliott Hill Park. 19 Figure 2.5 - Speculative Historic Tree Histogram for Elliott Hill Park, 19 Figure 2.7- Existing Conditions - Patches & Tiers 20 Figure 2.8 - Student team collecting data in Patch C. 20 Figure 2.9 - Student team walking through NW section of Patch B. 20 Figure 2.10- Photograph taken from Patch C facing 20 toward Patch D. 20 Figure 2.12 - Diagrammatic Section showing existing conditions at Elliott Hill Park. 21 Figure 2.11 - Tree Histogram for a sample plot in Patch B generated student data collection 21 Figure 2.13- Desired Future Conditions at Elliott Hill Park 22 Figure 2.14- Example of overgrown patch of remnant oak savanna 22 Figure 2.15- Example of same area immediately after thinning 22 Figure 2.16- Example of same area several years after thinning. 22 Figure 2.18 - Diagrammatic Section illustrating DFCs in Elliott Hill Park 23 Figure 2.17 - Tree Histogram for DFC in Patch B (Woodland) 23 Figure 2.19 - Table of Management Speices 25 Referenced Student Species Reports 26 Figure 2.20 - Diagrammatic Section illustrating species-specific recommendations 27 Class Exercise Reading 28 Figure 3.2- Neighborhood oak of importance- Old Growth (60-70 feet ~150 years) 32 Figure 3.3- Existing patch example in neighborhood 32 Figure 3.4- Ideal oak savanna aesthetic on private residential property 32 Figure 3.5- Example of a House in the neighborhood that shows potential for time line assessing 34
Figure 3.6- Spencerâ&#x20AC;&#x2122;s butte Figure 3. 7- Example Project Time line with process assessment Figure 3.9- Existing house in historic oak savanna Figure 3.8- Existing house in historic Upland Prairie Figure 7- Residential Matrix Design Strategy Figure 3.10- Residential Design recommendations for White-breasted Figure 3.11- Residential Design recommendations for Pocket Gopher habitat. Figure 4.1 - Differences in tree form - oak canopy restricted by adjacent firs Figure 4.2- Mt. Pisgah Arboretum could be connected through corridors Figure 4.3- Oak tree within utility infrastructure along residential road Figure 4.4- Tier Analysis of South Eugene Area Figure 4.5- Property Acquisition plan based on Tax Lot Analysis Figure 4.6 -High Priority Areas for Cooperative Management based on Tax Lot Analysis Figure 4.7- Cooperative management of to create buffer zones around core habitats Figure 4.8- Cooperative management for corridor connectivity Figure 4.9- Potential for realized oak savanna and connectivity beyond the UGB
34 34 35 35 35 36 36 40 40 40 41 42 43 43 43 44
47