Watershed Forest Master Plan

Page 1

Watershed Forest Master Plan


2


Table of Contents Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg 04 State of the Urban Forest . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg 07 Vision for the Urban Forest. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg 29 Recommendations for the Urban Forest. . . . . . . . . . . . . . . . . . . . . . . pg 33

Watershed Recommendations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg 34

Community Space Recommendations. . . . . . . . . . . . . . . . . . . . . pg 43

Residential Recommendations. . . . . . . . . . . . . . . . . . . . . . . . . . . . pg 46

Commercial Recommendations. . . . . . . . . . . . . . . . . . . . . . . . . . . pg 48

Summary of Recommendations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg 50 Monitoring Progress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg 51 Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . pg 53

3


I NTRODU CTION The Watershed Residential settlement of the region began in the 1760’s, and in the next century Pittsburgh became a booming center of trade. With three rivers for transportation and rich deposits of coal and natural gas, the area was an excellent choice for manufacturing and industry. By 1900, steel mills, glass factories, and other manufacturing facilities lined the rivers. Small residential communities formed around these facilities to accommodate the growing demand for labor, and by 1910, the 6.5 square miles of the Nine Mile Run (NMR) Watershed was collecting stormwater runoff from portions of the City of Pittsburgh and the boroughs of Edgewood, Wilkinsburg, and Swissvale. After World War II, trade routes in the region developed into major transportation corridors that traveled through the NMR Watershed. Interstate 376 is the primary route from the East into the City of Pittsburgh, and eventually crosses NMR before it enters the Squirrel Hill Tunnel. The Port Authority of Allegheny County’s Martin Luther King Jr. East Busway is a bus-only highway that follows a section of railway owned by Norfolk Southern Railway, and is an important transportation option for many watershed residents. The train and bus route bisects Wilkinsburg, Edgewood, and Swissvale in the watershed. Finally, South Braddock Ave, Forbes Ave, and Penn Ave are the major interior streets for commuters and experience daily vehicular congestion. Despite an urban transformation, the NMR Watershed contains many notable green spaces across the four municipalities; the most noteworthy is Frick Park. In his report published in 1911, Frederick Law Olmsted Jr.

4


wrote, “Perhaps the most striking opportunity noted for a large park is the valley of Nine Mile Run. Its long meadows of varying width would make ideal playfields; the stream, when freed from sewage, will be an attractive and interesting element in the landscape; the wooded slopes on either side give ample opportunity for enjoyment of the forest, for shaded walks and cool resting places” [1]. Established in 1927, Frick Park has grown to include 644 acres, is the largest of the City of Pittsburgh’s parks, and contributes significantly to the watershed’s 34% open green space. The park’s contiguous green space is further enlarged by The Homewood Cemetery property. The 178 acre, lawn-park style cemetery is an Accredited Level I Arboretum. The small creeks that drain these two green spaces test well for water quality. The Stream The degradation of NMR coincided with the development of the communities that surround it. When the municipalities of Edgewood, Swissvale, and Wilkinsburg formed, each buried NMR tributaries inside culverts and directed their stormwater flow through them. During wet weather, municipal sanitary systems often overflow into the stormwater culverts impacting the health of NMR and ultimately, the Monongahela River. Additionally, Duquesne Slag Company utilized land adjacent to NMR as an area to dump slag, an industrial by-product formed from the smelting of metal. By the fifties, a rail spur had been built to continue the mass depositing of slag–which already was over one hundred feet high. In 1972, the last slag was dumped at the NMR site [2]; the company went bankrupt shortly thereafter. Though discussed for many years, the effort to restore the stream would not begin in earnest until 1998. Nine Mile Run in Frick Park is one of the few open urban streams in the City of Pittsburgh. Though traditionally viewed as a problem rather than an asset, the stream has been restored to an ecological resource and recreational amenity in the area. In the late 1990s, the City of Pittsburgh coordinated an independent study of the NMR Watershed through a grant from the State of Pennsylvania Department of Conservation and Natural Resources. The STUDIO for Creative Inquiry at Carnegie Mellon University, the Carnegie Museum of Natural History, and the Landscape Architecture Department of Pennsylvania State University published their final report, “Nine Mile Run Watershed Rivers Conservation Plan,” in August 1998 [3]. The report’s findings, combined with the decision by the URA to develop new residences on top of the slag pile adjacent to the NMR stream, led to a decision to restore rather than culvert and bury the stream. In the early 2000’s, the US Army Corps of Engineers was authorized to restore the degraded aquatic ecosystem.

5


The Association Incorporated in 2001, Nine Mile Run Watershed Association (NMRWA) was formed to lead the outreach effort in the surrounding communities impacted by the construction. Since the completion of the restoration project in 2006, NMRWA’s mission has grown into a broader scope. NMRWA restores and protects its watershed ecosystem, while working regionally to support and implement resilient solutions for a healthy urban environment. Our goal is to give citizens and elected officials the information and tools they need to make positive changes in their communities, and to model sustainable practices. The Urban Forestry program is a key area in which we engage citizens and elected officials to help improve quality of life with trees as well as mitigate the excess stormwater runoff that still impacts NMR. In recognition of the importance of urban forestry, the U.S Conference of Mayors conducted an urban forestry survey of 135 U.S cities with populations of 30,000 or more. Their 2008 final report recognizes “the invaluable role of urban forests in the protection of public health and the reduction of harmful greenhouse gases.” According to the results, 95% of the cities surveyed have adopted tree management ordinances; 47% have enlarging tree canopy as a goal; and 70% maintain tree inventories [4]. As urban areas like Pittsburgh expand, and climate change progresses, the urban forest will become more critical to the comfort and sustainability of cities. WILL MAKE This Watershed Forest Master Plan has been created to help us URBAN build on our successes, lend support to new initiatives, and give FORESTS the Urban Forestry program the strategic direction to achieve the MORE CRITICAL maximum impact in the short and long term by:

CLIMATE CHANGE

• Increasing our utilization of the watershed’s forest as a tool to help address growing environmental challenges.

TO LOCAL COMMUNITIES

• Establishing baseline metrics and making implementable recommendations for the watershed’s urban forest and the communities that reside within its boundaries. • Creating a coordinated vision among watershed municipalities; namely Pittsburgh, Wilkinsburg, Swissvale, and Edgewood. • Increasing citizen participation in the planning, growth, and stewardship of the watershed’s urban forest.

6


STATE OF THE U R B A N F O R E S T: An urban forest is made up of all woody vegetation in and around a city. The Nine Mile Run Watershed’s forest exists within four municipalities and includes their respective street, park, private landscape, cemetery, school campus, and woodland trees. Championing urban forests and managing their trees is not simply a activist exercise, but an essential practice for supporting public health, mitigating climate change, and creating places worth caring about–especially as urban areas continue to expand. To understand the best approach to managing this resource, data on current conditions and related research must be collected and analyzed. This section examines the multiple components that influence and characterize the state of the NMR Watershed forest and stream, with a special emphasis on Wilkinsburg, Swissvale, and Edgewood Boroughs.

We share a century-old London planetree with our neighbors and we love it! Our kids play under it, it provides beauty on our street and the shade it provides to our house helps significantly with our utilities in the warm months.

~ Kelsey

7


Nine Mile Run Monitoring Review Since the establishment of NMRWA, improving the health of the Nine Mile Run stream in Frick Park has been a top priority. The Association established a Monitoring Committee in 2006, which oversees the protocols and standards for assessing stream health. Water quality data is collected by NMRWA staff and volunteers. Utilizing state and federal regulations, key water quality parameters are graded based on pre-restoration, postrestoration, and current data [5]. The NMR stream restoration significantly improved water quality. This improvement is reflected by increased wildlife abundance and diversity. However, the stream is still affected by inputs from the surrounding urban environment, indicated by the presence of high nitrogen, bacteria, and metal levels. The NMRWA website publishes annual monitoring results. Stakeholders Because of the variety of land uses contained within the watershed forest, coordinating with diverse partners is essential to meeting goals that support the health and vigor of its tree population. These trees are a vital part of a healthy ecosystem as they purify and cool the air, collect and clean stormwater, and add beauty to our urban environment. With leadership, planning, and community involvement, progress can be realized and benefits to quality of life experienced. The watershed is home to numerous nonprofit organizations, municipal groups, utility providers, and other stakeholders as well as related planning documents that impact the watershed forest.

Some of the planning documents that impact the watershed forest: • National Urban and Community Forestry Advisory Council 10 Year Urban Forestry Action Plan 2016-2026 • Pittsburgh Climate Action Plan • Pittsburgh Urban Forest Master Plan • Pittsburgh Parks Conservancy Regional Parks Master Plan • Pittsburgh Water & Sewer Authority City-Wide Green First Plan • Edgewood, Swissvale and Rankin Comprehensive Plan • Wilkinsburg Comprehensive Plan

Nonprofit Organizations & Related Programs • Nine Mile Run Watershed Association – Works to restore and protect its watershed ecosystem, particularly through programs to reduce stormwater entering Nine Mile Run. • Wilkinsburg Community Development Corporation – Promotes the revitalization of Wilkinsburg which includes greening projects. • Regent Square Civic Association – Works to enhance the quality of life for residents, businesses, and land owners in Regent Square which includes planting trees.

8


• Pittsburgh Parks Conservancy – Improving quality of life through park programs and projects with respect to the environment, historic design, and needs of a diverse population. • Tree Pittsburgh – Enhances Pittsburgh’s vitality by restoring and protecting the urban forest. • Western Pennsylvania Conservancy – Creates green spaces and gardens contributing to the vitality of cities. • TreeVitalize Pittsburgh – A program of the Pennsylvania Department of Conservation and Natural Resources that supports neighborhood initiatives to plant street and park trees annually in the City of Pittsburgh and the surrounding region. • Urban EcoSteward Program – A volunteer program utilized by several organizations to provide continuous invasive plant management in parks and woodlands to promote a healthy ecosystem. • Tree Tenders Program – Offered by Tree Pittsburgh, this is a citizen certification program specializing in tree biology, planting, establishment, maintenance, and advocacy. Municipal Groups • Wilkinsburg Borough (Wilkinsburg Citizen Advisory Committee on Shade Trees) – Annually budgets for tree work in the borough utilizing a tree committee to advocate for and coordinate tree-related activities. • Edgewood Borough (Edgewood Shade Tree Committee) – Annually budgets for tree work and involves residents on a tree committee to help guide decisions. • Swissvale Borough (Swissvale Shade Tree Advisory Committee) – Annually budgets for tree work and utilizes a tree committee to promote trees in the borough. • City of Pittsburgh Forestry Division – Division of public works responsible for coordinating and implementing street and park tree maintenance. • Pittsburgh Shade Tree Commission – Tasked with restoring and maintaining the city’s tree population. Utility Providers • Allegheny County Sanitary Authority (ALCOSAN) – Wastewater treatment provider for 83 municipalities including the City of Pittsburgh; and works to address combined sewer overflows in service area. • Duquesne Light Company – Electrical energy provider that utilizes a vegetation management team to prune trees for reliable energy service. • People’s Natural Gas / Columbia Gas of Pennsylvania – Natural gas providers that experience conflicts with trees when maintaining service lines in municipalities. • Wilkinsburg Penn Joint Water Authority – Water provider within the watershed and an important partner in hydrating young trees. • Pittsburgh Water and Sewer Authority – City of Pittsburgh public agency tasked with maintaining water and sewer infrastructure and clean drinking water for residents. • Port Authority of Allegheny County – Provides public transportation throughout Pittsburgh and Allegheny County.

9


Other Stakeholders • Cemeteries – Host and manage trees on large plots of land that contain little impervious surface. • Tree Care Companies – Contracted by residents and by private and public groups to perform tree maintenance. • Public and Private Schools - Host and manage campus trees and other landscape features. Significant Community and Impervious Parcels The watershed forest contains a diverse array of public and institutional spaces that positively contribute to the overall tree population. Frick Park, The Homewood Cemetery, and Smithfield East End Cemetery, amalgamated, represent a significant portion of the watershed’s green space. Wilkinsburg, Swissvale, and Edgewood also host parks, community gardens, and school campuses of various sizes that improve connectivity and access to the universal benefits of green spaces throughout residential neighborhoods. The NMR stream’s health is significantly affected by not only the watershed forest, but also by the size and distribution of impervious surfaces. Stormwater runoff is accelerated over impervious surfaces, and additionally, carries water pollutants. The most noteworthy sites of highly accumulated impervious surface include the Petra Ministries/U-Pull-&-Pay parcels, the Edgewood Towne Centre, Port Authority of Allegheny County’s Wilkinsburg Station parking lot, and Wilkinsburg commercial lots and business district. Canopy Cover The concentration of the United States (US) population in urban areas is projected to increase substantially over the next half-century. In 2001, 3.1% of urban land in the continental US supported 79% of the population. As urban areas continue to expand and the need for trees to combat climate change increases, a well-planned and managed urban forest will be essential to quality of life. Nationally, urban forests are estimated to contain about 3.8 billion trees, but the spatial distribution and patterns of canopy cover vary from city to city depending on the location and size, resident population, development patterns, and surrounding natural vegetation [6]. Assessing tree canopy cover involves an analysis of a specified land area to determine the amount covered by tree canopy. In 2010 and 2015, Tree Pittsburgh performed assessments of Allegheny County’s tree canopy utilizing USDA Forest Service’s Tree Canopy Assessment Protocols. The data indicates an overall tree canopy loss of approximately 2.4% across the entire land area of the watershed; equating to an estimated 97 acres. Yet, there are also areas of notable gain; specifically the Nine Mile Run restoration area in Frick Park which is ten years post-restoration. The net loss of tree canopy equates to thousands of trees lost between 2010 and 2015 despite tree planting efforts. A closer look at tree canopy loss in the watershed shows that isolated, propertyto-property tree removal is a significant factor in the declining canopy cover trend. This threat to canopy is in addition to other tree losses due to pests, disease, or natural causes, infrastructure maintenance, property reinvestments, and new construction. The magnitude by which each of these tree loss factors has contributed to the overall canopy loss is to be determined [7].

10


Nine Mile Run Watershed

Swissvale

Legend Parks

Legend

Greenways Cemetery

Parks

School Campus

Community Gardens

Civic Buildings

Civic Buildings

City Parcels

School Campus

City Boundary

Swissvale Parcels

NMR Watershed

Swissvale Boundary

Watershed Municipalities

Watershed Municipalities

NMR Stream

NMR Stream NMR Culvert System

NMR Culvert System 0

0.45

0.9 Miles

[

0

Esri, HERE, DeLorme, MapmyIndia, © OpenStreetMap contributors, and the GIS user community

Wilkinsburg

0.15

0.3

0.6 Miles

[

Esri, HERE, DeLorme, MapmyIndia, © OpenStreetMap contributors, and the GIS user community

Edgewood

Legend Legend

Parks Community Gardens

Parks

Cemetery

School Campus

School Campus

Civic Buildings

Borough Building

Edgewood Parcels

Parcels

Edgewood Boundary

Wilkinsburg

Watershed Municipalities

NMR Stream

NMR Stream

NMR Culvert System 0

Edgewood

0.15

0.3

[

0.6 Miles

Esri, HERE, DeLorme, MapmyIndia, © OpenStreetMap contributors, and the GIS user community, Esri, HERE, MapmyIndia, © OpenStreetMap contributors, and the GIS user community

NMR Culvert System

Wilkinsburg

0

0.15

0.3 Miles

[

Esri, HERE, DeLorme, MapmyIndia, © OpenStreetMap contributors, and the GIS user community

Legend Wilkinsburg Commercial Lots Wilkinsburg Business District PAT Park n Ride

Legend

Wilkinsburg Parcels

A BR DD OC K

Edgewood Town Center

Pervious Surface

Edgewood Parcels

Impervious Surface

Pervious Surface

Watershed Municipalities

Impervious Surface

NMR Stream

Watershed Municipalities

NMR Culvert System

NMR Stream NMR Culvert System

East Hills

0

155

310

620 Feet

[

0

410

820

1,640 Feet

[

Esri, HERE, DeLorme, MapmyIndia, © OpenStreetMap contributors, and the GIS user community

Esri, HERE, DeLorme, MapmyIndia, © OpenStreetMap contributors, and the GIS user community

Legend Petra Ministries and UP&P Pervious Surface Impervious Surface Watershed Municipalities NMR Stream NMR Culvert System 0

237.5

475

950 Feet

[

Esri, HERE, DeLorme, MapmyIndia, © OpenStreetMap contributors, and the GIS user community

11


Tree Canopy Cover 2010-2015 Comparison Boundary

2010 % Canopy

2015 % Canopy

Canopy Loss in Acres

Edgewood

53.4

50.5

11

Swissvale

38.1

35.8

18

Wilkinsburg

44.4

41.9

36

Watershed

49.4

47.0

97

Estimated Tree Loss 2010-2015 Boundary

Canopy Loss in Acres

Total Estimated Trees Lost

Trees/Yr Lost: 2010-2015

Edgewood

11

1,090

218

Swissvale

18

1,771

354

Wilkinsburg

36

3,604

721

Watershed

97

9,704

1,941

Encouragingly, overall tree canopy cover in the boroughs and the watershed is already quite high when compared to other local boroughs and regional cities. Additional gains of at least 374 acres in overall canopy cover could theoretically be approached by establishing complete canopy coverage within the public right-of-way. More practically, the canopy loss trend could be mitigated by targeting increases of 50% in the public right-of-way, 25% on both government and industrial land, 10% on commercial land, and 10% on residential and utility land [8].

Local Comparisons

% Canopy Cover

Year

Regional Comparisons

% Canopy Cover

Year

NMR Watershed

47.0

2015

State College, PA

39

2009

Allegheny County

54.0

2015

Cleveland, OH

19

2013

Pittsburgh

40.8

2015

Columbus, OH

22

2013

Homestead

29.9

2015

Cumberland, MD

49

2008

Dormont

24.3

2015

Bellevue

39.6

2015

Etna

32.2

2015

12


Maintaining and growing urban tree canopy influences thermal comfort, energy use, and air quality, ultimately reducing the impact of industry. Carbon storage, water runoff mitigation, water quality, and wildlife habitat are important benefits of preserving tree canopy as well. Enhancing urban canopy cover will generally increase the benefits derived from urban forests; however, it can also potentially increase costs and risks (such as maintenance work, property damage, and hazardous situations). To stabilize and reverse the canopy cover trends within the watershed forest, understanding where, how, and why we are growing tree canopy must be carefully considered for optimal results [6]. Street Tree Analysis Street trees are the most visible and vulnerable trees in an urban forest. As an important piece of public infrastructure, street trees are positioned to have the greatest impact on a community’s quality of life. For example, street trees slow the movement of rainfall to stormwater systems, shade heat-trapping impervious surfaces, and grab harmful pollutants along the streets and boulevards, creating a more pleasant environment for everyone. In 2017, we contracted for a professional street tree inventory for Wilkinsburg, Edgewood, and Swissvale, producing a needed update to our previous volunteer-based inventories. 2014 street tree data for the City of Pittsburgh was acquired to allow data analysis at the watershed level. Finally, volunteers were utilized to inventory and map municipal park landscape trees.

! ! !! ! ! ! !! ! !! ! ! !! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! !! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! !! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! !! !!! ! !! !! ! !! ! ! ! ! !!!! !! ! !! !! ! ! ! !! !!! !! ! !! !! !!! ! ! !! ! ! ! !! ! ! ! ! ! ! ! !! ! !!

! ! !! !! ! !!! ! !! ! ! !! ! !!! !! ! ! !! ! ! ! ! ! !!! ! ! !! ! !! ! ! ! !!! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! !! !! !! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !!! ! ! ! ! ! !! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! !! ! ! ! ! !! ! ! ! !! ! !!! ! ! ! !!! !! ! !!!! ! ! ! ! !! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! !!! !! ! ! ! ! ! ! ! ! ! ! ! ! !!! !!!! ! !! ! ! ! ! ! !! ! ! ! ! !!! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! !!!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !!! ! ! ! ! ! ! !! ! !! ! ! ! ! ! !!! !! ! !!!! ! !!! !! ! !! ! ! ! ! !!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !!! ! ! ! ! ! ! ! !! ! ! !! ! !!! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! !! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! !!! !! ! ! ! ! ! ! ! ! !! ! ! ! ! !! ! ! !! ! ! ! !! !! ! ! !! ! !! ! ! ! ! !! ! ! !! !! !! !! ! ! ! !! !! ! ! ! !! ! ! !! ! ! !!! ! !! ! !!!!! !! ! !! ! ! ! ! ! ! ! ! ! ! ! !! ! !!!! ! ! ! ! ! ! ! !! ! ! ! ! !!!!!!!! ! !! ! !!! ! ! ! ! !!! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! !! ! !!! ! !! ! ! !!!! ! ! ! !!!!! ! ! !!!! ! ! ! ! ! ! !!! ! ! ! ! ! ! !! ! ! ! !! ! ! ! ! ! ! ! ! !!! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! !! ! ! !!! ! ! ! ! ! !!! !!!! ! ! !! ! ! !!!! ! !! ! ! ! ! ! ! !!! !! ! !!! ! !! !! ! ! !! ! ! ! ! ! !! ! ! !! !! ! ! !! ! !! ! ! ! ! !! ! ! ! ! ! ! ! ! ! !!! ! ! ! !!!! !! !! ! ! ! !! !! !! !!! ! ! ! ! !! ! ! ! ! ! ! ! !! ! !!!! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! !! ! ! ! ! !!! ! !!! ! !! !! !!! ! ! ! ! ! ! !! ! ! ! ! !! ! ! ! ! !! !! !! ! ! !! ! !! !! !!!! ! !! ! !! ! !!! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! !!! ! !!! !! !! ! ! ! ! !! ! !! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! !! ! !!! ! ! ! ! ! ! !! ! !! !! ! ! !! ! ! !! ! !!! ! ! ! ! ! ! ! ! ! ! !!! ! ! ! !! ! ! ! ! !! ! ! ! ! !! ! !! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! !! !! !! ! !!! ! !! ! ! ! !! !! ! ! ! ! ! !! ! ! ! !! ! ! !! ! ! !! ! ! ! ! ! !!! !!!!! ! !! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! !!! ! ! ! ! ! !!! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! !!!! !! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! !! ! ! ! !!! ! ! ! ! !! ! ! ! ! ! ! !!! ! ! !! ! ! ! ! ! !! ! !! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! !!! ! ! !! ! ! !! !! ! ! !!!! ! ! ! !! ! ! ! ! ! ! !!! !! ! !! ! ! !! !! !!! ! ! !!!! !!!! ! !! !!! ! ! ! ! ! !!! ! ! ! ! ! ! !!!!!!! ! !! ! !! !!!! ! ! ! !! ! ! ! ! !! ! ! ! !! ! ! ! ! !! ! ! !! ! !! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! !!! ! !!! ! ! ! ! !! ! !! !! ! ! ! !! !! ! ! ! ! !! ! !! !! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! !! ! ! ! ! ! ! !!! ! ! ! !! ! ! ! ! ! ! ! !!!! !!! ! !! ! ! ! ! ! ! ! !! ! !!! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! !! ! !! ! ! !! ! !! !! !! !! !! ! ! ! ! !! ! !! !! ! ! ! ! ! ! ! ! !!! !! ! ! ! ! !! !! ! ! ! ! ! ! !! ! ! ! !! !!! !! ! !! ! ! ! ! ! ! ! ! ! !!! ! ! ! ! !!! ! ! ! !!! ! ! !!!!! ! !! ! ! !!! ! !! !! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! !!!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! !! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! !! ! ! ! !! !! !! ! !! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! !! !! ! !! ! !!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! !! !! ! ! ! ! ! !! ! ! ! !!!!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! !! !!! ! ! ! ! ! ! !!!!! ! ! ! ! ! ! ! ! ! ! !! ! ! ! !!!! ! ! !! !!! ! ! ! ! ! !!! !!! !!! ! !! ! ! ! ! ! !!! ! ! !!! ! ! ! ! ! ! ! ! !! ! ! !! ! ! ! ! ! ! ! ! ! !! ! !! ! ! ! ! !! ! !! ! ! !!!! ! ! !! ! ! !!! ! ! !! ! ! !! ! ! ! !! ! !! ! !! ! ! !! ! ! ! ! ! !!! !! ! ! !! !!!! ! ! ! ! ! ! !! !! !! !!!!! ! !! !! ! ! !! ! ! ! ! ! ! ! ! ! !! !! ! !!! ! ! ! ! ! ! ! !! !! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! !! ! ! ! ! ! ! ! !! ! ! ! !! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! !!!! ! ! !! ! ! ! ! ! ! ! !! ! ! ! ! ! ! !! ! ! !!!!! !! !! ! ! ! !! ! ! ! ! ! ! !!! ! !!! ! ! ! !!! ! !! ! ! ! ! ! !!! ! !!! ! ! ! ! !! !!! ! ! ! ! !! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! !!! !! ! ! ! !!! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! !! ! ! ! ! ! !!! ! ! ! ! ! !! ! !! ! !! ! ! ! ! ! !! ! !!! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! !!! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! !! !! ! !!!!!!! ! !! ! ! !! ! !! ! ! ! !! !! !!!! ! ! !! ! !! !! ! !! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! !!! ! ! ! ! ! ! ! ! !! !! !!!! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! !! ! !! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !!! !!! !! !! ! ! ! !! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! !!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! !! ! ! ! ! ! !! ! !! !! !! ! ! !!! ! ! ! !! !! ! !! !! ! ! ! !! ! ! ! ! !! !! ! ! ! ! ! ! ! ! ! ! !! ! !! !! ! ! ! !! ! !! ! ! ! ! !! ! !!!! !! !! ! ! ! ! ! !! !! ! ! ! ! ! !! !! ! !! ! ! ! ! !! ! ! ! ! ! ! ! !! ! !! ! ! ! !! ! ! ! ! ! ! ! !! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !!! ! ! ! ! ! ! ! ! !! ! ! ! ! !!! ! ! ! ! !!! ! ! ! ! !! ! ! ! ! ! ! ! ! ! !!! ! ! ! !! ! !!! ! ! !!! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! !! ! ! !! !! ! ! ! ! ! !!!!! ! ! ! !! ! ! ! ! ! !! ! !! ! ! ! ! ! ! !!!! ! ! ! ! ! ! ! ! ! ! !! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! !! !!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! !! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! !! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! !! ! !! !! ! ! !! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! !! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! !! ! ! ! !! !! ! !! ! ! ! ! !! !! ! ! ! !! ! ! ! ! ! ! ! ! ! !

! ! ! ! ! ! !! !! !! ! ! ! ! ! !! ! ! ! !! ! !! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !!! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! !! ! ! !! !!! !!! ! ! ! ! !! ! ! !! ! ! ! !! ! ! ! ! !! ! ! ! ! ! ! ! !! ! ! !! !! !! ! ! ! !! ! !! ! ! !! !! ! ! ! ! !! !! ! ! ! !! !

! !

Legend !

Street Trees NMR Watershed NMR Stream NMR Culvert System

0

0.25

0.5

1 Miles

[

Esri, HERE, DeLorme, MapmyIndia, © OpenStreetMap contributors, and the GIS user community, Esri, HERE, MapmyIndia, © OpenStreetMap contributors, and the GIS user community

13


Plotting the diameter distribution of a street tree population helps us understand if recent planting efforts are sufficient for long term sustainability of the urban forest. Ideally, charting diameter classes should show a negative sloping trend from the smallest to largest diameters. The diameter distribution for the watershed street tree population nearly meets this metric, but trees in the 0-3 inch size class are beginning to fall behind. The trend is weaker when assessed by borough.

Watershed Diameter Distribution 1200

1000

800

600

400

200

0

00”-03”

04”-06”

07”-12”

13”-18”

19”-24”

25”-30”

31”-36”

37”-42”

43”+

Diameter Distribution by Borough 350 Wilkinsburg Edgewood

300

Swissvale 250

200

150

100

50

0

00”-03”

04”-06”

07”-12”

13”-18”

19”-24”

25”-30”

31”-36”

37”-42”

43”+

The watershed contains a reasonably diverse array of 124 species of trees along our streets, but the proportions of each species could improve. London planetree (Platanus x. acerifolia) and pin oak (Quercus palustris) together comprise 31% of the street tree population in the watershed, 55% in Edgewood, 35% in Swissvale, and 32% in Wilkinsburg. The maple genus (Acer) comprises 27% of the population alone. Additionally, trees in the maple and elm genus (Ulmus) have been the top two genera planted since 2003. Incorporating diverse tree species in planting efforts is critical for

14


ecological resiliency to proactively combat the effects of destructive pests and diseases as well as support an array of benefits. The guiding metric for species diversity is to have no more than 10% of any species, and furthermore, to have no more than 20% or 30% of any genus or family, respectively, to minimize damages caused by unknown future pests and diseases. Comparisons to 2005 inventory data demonstrate that species diversity is improving at the watershed and municipal levels, and furthermore, the overall street tree count has increased for the watershed with Pittsburgh and Wilkinsburg experiencing net gains. The TreeVitalize Pittsburgh program has been a major contributor to this net gain, having partnered with us to plant over 1,100 trees between 2008 and 2017 in the watershed. 500 of these were planted as part of the Wilkinsburg TreeVitalize “Rooted in Wilkinsburg: 500 Tree Initiative� (2011-2013). Conversely, Edgewood and Swissvale tree counts have decreased since 2005.

15


2005 Watershed Top Species

% Pop.

2017 Watershed Top Species

% Pop.

London planetree

21%

London planetree

18

Norway maple

15%

pin oak

13

pin oak

15%

Norway maple

9

red maple

10%

red maple

9

2005 Wilkinsburg Top Species

% Pop.

2017 Wilkinsburg Top Species

% Pop.

pin oak

26

pin oak

21

Norway maple

25

Norway maple

13

London plantetree

12

honeylocust

8

honeylocust

8

London planetree

8

2005 Edgewood Top Species

% Pop.

2017 Edgewood Top Species

% Pop.

pin oak

30

London planetree

28

London planetree

27

pin oak

27

crabapple

15

crabapple

13

Norway maple

5

ornamental pear

4

2005 Swissvale Top Species

% Pop.

2017 Swissvale Top Species

% Pop.

London planetree

30

London planetree

21

pin oak

14

pin oak

14

red maple

13

red maple

9

little-leaf linden

7

ornamental pear

7

Tree Count Comparisons 2005 vs. 2017 2005

2017

Edgewood

895

691

Wilkinsburg

1,224

1,677

Swissvale

696

669

Pittsburgh(watershed)

2,312

2,743

Total

5,127

5,780

Historically, municipal urban forest managers have had difficulty sustaining the resources needed to complete basic tasks such as tree planting, pruning, and removal [9]. Without proactive annual management, two trees of similar size, age, and species may not provide similar levels of benefits in stormwater, air quality, and carbon sequestration due to differences in vigor. Street tree health is negatively impacted, for example, by poor pruning, vehicular damage, root loss, and winter de-icing salt. 80% of the street trees are in good or fair condition (34% and 46% respectively) in the watershed. Executing a tree management plan annually is essential to maintaining a healthy urban forest.

16


Watershed Street Tree Health 3000

Trees

2500

2000

1500

1000

500

0

Fair

Good

Poor

Dead

Condition

Tree Health by Borough Wilkinsburg Edgewood

Good

Swissvale

Fair

Poor

Dead

0

100

200

300

400

500

600

700

800

Annual Public Benefits of Watershed Street Trees Trees provide a range of environmental and social benefits that, together, constitute a resource of significant value. While the total watershed forest benefits are currently undetermined, the street tree population alone is providing over $800,000 in benefits annually (a decrease from 2005’s total). Tree species and relative location dictates the long term benefits realized per tree. Therefore, desired outcomes of a tree planting should be determined in the early stages of any project. Tools such as i-Tree Eco can help tree planting coordinators understand how the number of trees, species, and placement will impact individual benefits over time. Through stormwater mitigation, carbon sequestration, energy savings, aesthetic value, improved public health, and wildlife habitat, the urban forest significantly enhances residents’ quality of life.

17


Watershed Street Tree Benefits($) 2017 Geographic Area

#Trees

Energy

Carbon Dioxide

Air Quality

Stormwater

Aesthetic

Total

NMR Watershed

5,596

$343,760

$9,100

$62,280

$90,840

$310,500

$816,480

Wilkinsburg

1,677

$103,600

$2,910

$19,240

$27,335

$98,040

$251,125

Swissvale

669

$43,900

$1,160

$7,920

$11,830

$38,720

$103,530

Edgewood

691

$55,250

$1,620

$10,475

$16,360

$45,300

$129,005

Watershed Street Tree Benefit($) Comparison to 2005

Geographic Area

2017 Tree Count

Value($) in 2017

2005 Tree Count

Value($) in 2005

NMR Watershed

5,596

$816,480

4,881

$1,458,600

Wilkinsburg

1,677

$251,125

1,224

$191,456

Swissvale

669

$103,530

696

$108,632

Edgewood

691

$129,005

895

$159,558

Stormwater Computer models estimate that 9 billion gallons of wastewater are discharged from 350 ALCOSAN and municipal combined sewer overflow outfalls scattered throughout the service area that degrade our waterways and reduce quality of life in neighborhoods. The ALCOSAN M-47-OF (Nine Mile Run) outfall experiences an average of 65 annual combined sewer overflow events, contributing at least 226 million gallons of contaminated water to the Monongahela River [10]. Trees reduce stormwater runoff, particularly over impervious surfaces, by capturing and slowing rainfall by their physical mass, and further, support soil conditions that promote infiltration of rainwater into the soil and prevent erosion. Additionally, trees reduce pollutants in our streams and rivers by filtering water contaminants with their roots [11]. According to the 2017 i-Tree analysis, the watershed’s street tree population is currently removing 11 million gallons of stormwater from the system each year; a conservative value of over $90,000 annually. Installing trees that will shade impervious surfaces and possibly be contained within stormwater tree pits could reduce total runoff even further. Carbon Trees and forests have long been acknowledged for their carbon dioxide storage and mitigation [12]. Trees sequester and store carbon in their tissue at differing rates and amounts based on such factors as size at maturity, life-span, site conditions, and growth rate. According to the 2017 i-Tree analysis, street trees in the watershed currently sequester 2.7 million pounds of carbon. WATERSHED To maximize the net benefits of urban forestry on atmospheric carbon, efforts should focus on protecting woodlands, and TREES planting long-lived, low maintenance, moderate to fast growing PROVIDE trees in public spaces. For property owners, planting with $800,000+ energy conservation in mind is important. Finally, maintenance activities that increase tree survival and longevity are best [12]. IN ANNUAL

BENEFITS.

18


Energy Use The watershed forest reduces energy usage in air conditioned homes and facilities. Shade trees strategically placed around a building block incoming solar radiation on windows and walls, thus effectively lowering daily and monthly cooling demand. Tree shade can reduce sunlight on structures by roughly 25% and reduce electricity used for cooling by an estimated 13%. According to the 2017 i-Tree analysis, watershed street trees currently save area residents as a whole $343,000 annually on energy costs. Tree canopy helps reduce the heat island effect in areas of high impervious surfaces which reduces overall ambient air temperatures, and properly placed trees can dampen prevailing winter winds for a winter energy use saving of 10-15% [13, 14]. This reduction in demand and energy usage results in an avoided release of air pollutants at nearby power plants. Aesthetics/Property Value From hardscape to softscape, decisions on a home’s surrounding landscape can impact property value, particularly with the trees. Research indicates that tree cover has an overall positive monetary effect (around 10%) on the sale price of homes [15]. Furthermore, properties in close proximity to parks (which usually include trees) tend to be more valuable as well [16]. The aesthetic value of the watershed’s street trees is currently valued at $310,500 annually. Public Health The public health benefits (air quality, walkability, mental health, physical health) of the urban forest are less intuitive and more challenging to quantify. Additionally, they are not always considered as a goal of tree management. Discernible improvements have been demonstrated when comparing rates of headaches, level of stress, and calmness before and after visiting urban forests and parks [17]. Communicating this benefit more clearly could help increase funding for urban forestry initiatives [18].

There’s a pin oak [on] Rebecca. I see it out my window every morning and it makes me happy ~ Rayden

Natural features and open space play an important role in cultivating a greater sense of attachment to a community [19]. Presence of trees can be a decisive factor in the extent to which residents actually use and take ownership of residential outdoor spaces. Green spaces and the incorporation of trees in neighborhoods have been linked to greater outdoor usage by adults and children, thereby cultivating a tighter knit community. Furthermore, increased outdoor activity and a sense of ownership of public spaces helps reduce crime by fostering pedestrianism and increasing the likelihood of social interactions [20].

19


Pittsburgh’s Air Quality The American Lung Association ranks Pittsburgh 8th worst of more than 200 metro areas in the nation for long term soot pollution, 14th worst for short term or daily soot pollution, and 20th worst for ozone. Urban forests positively impact air quality both locally and regionally. Trees actively sequester particulate matter both day and night as particles adhere to foliar and bark surfaces. Watershed residents will breathe easiest during the daytime of the in-leaf season since urban trees most significantly impact the levels of ozone, sulfur dioxide, and nitrogen dioxide during this time (21). The watershed street trees are currently providing over $60,000 in air quality benefits annually. Identifying opportunities to install more evergreen trees near major transportation routes, will improve the effectiveness of reducing air pollutants. Wildlife Urban forests provide wildlife with habitat for breeding, shelter, and food at varying capacities based on the size of contiguous woodlands and the level of habitat fragmentation. Additionally, strategic conservation of urban green spaces can enhance the ability of wildlife to safely travel through a developed landscape. When compared to land use in 2000, urban land is on track to triple by 2030, nationally. Landscapes that benefit birds, butterflies, pollinators, and other insects need to be encouraged and created more regularly to sustain biodiversity [22]. Selecting trees that provide reliable food sources, increase planting diversity, and conducting tree maintenance that respects habitat are a few ways to support wildlife in the watershed forest [23]. Geographic Area

Value($) in 2017

$Benefit/Capita $Benefit/Tree

NMR Watershed 5,596

$816,480

N/A

$145.90

Wilkinsburg

1,677

$251,125

$16.11

$149.75

Edgewood

691

$129,005

$42.45

$186.69

Swissvale

669

$103,530

$11.53

$154.75

#Trees

Threats to the Watershed Forest The Nine Mile Run Watershed is a demonstrably disturbed and urban landscape containing a range of pressures and environmental conditions that threaten its overall health. Damage and mortality due to invasive plants, pests, and diseases pose significant economic, environmental, and aesthetic impacts. Additionally, the progression of climate change, and the related impacts will alter biodiversity in the region. Potential threats to urban forest health are not only biological, but can include social and economic factors (discussed further in Vision for Watershed Forest). Identifying these threats and determining proactive actions is essential to watershed forest management.

20


Pests • Emerald ash borer (EAB; Agrilus planipennis)- First found in western Pennsylvania in 2007, this non-native invasive beetle kills host ash trees in 3-5 years. The impact of EAB on the region’s ash (Fraxinus) population has already occurred. Overall, the pest has had minimal impact on street tree populations in the watershed since ash has comprised a very low percentage of the population since 2005. The level of impact to the watershed’s woodlands and overall canopy cover by EAB is substantial, but has not been quantified. • Asian longhorned beetle (ALB; Anoplophora glabripennis) Fortunately, ALB is not currently found in Pennsylvania. The closest quarantine area is 300 miles west in Cincinnati’s metro area. This invasive pest would have a devastating impact on trees if it made it to Pittsburgh. An estimated 67% of Pittsburgh’s urban forest is composed of species susceptible to ALB including but not limited to maple, buckeye, horsechestnut, elm, willow, and birch trees [24]. The maple genus makes up 25% of watershed street trees, but it likely comprises a much greater portion of the overall watershed forest. • Spotted lanternfly (Lycorma delicatula) - Spotted lanternfly was first identified in Pennsylvania in 2014. The insect attacks maples, walnuts, grapes, apples, stone fruits, tree of heaven, and many hardwood trees important to the logging industry. 13 counties in eastern Pennsylvania are currently under quarantine related to the pest. In the watershed, it could negatively impact urban fruit orchards, street trees, and woodlands [25]. Diseases • Oak Wilt - A fungus that rapidly kills trees in the broad red oak group (northern red, scarlet, black, and pin oaks) and can slowly kill oaks in the white oak group (white, bur, swamp white, and chestnut oaks). The destructive spores are spread by sap feeding beetles attracted to the fungus and then to fresh wounds on oaks. It can also be spread by root grafting. Isolated outbreaks have occurred in the watershed; primarily in Frick Park [26]. • Verticilium wilt - A vascular fungal disease that resides in the soil, and can move into xylem cells through wounding of a tree’s roots or lower trunk, leading to decline symptoms and eventual death. The disease impacts maples, redbuds, lilacs, catalpas, golden raintrees, smoketrees, and elms [26]. • Ganoderma root rot - One of the most widespread root and root flare decaying fungi of the urban forest, ganoderma root rot can infect most hardwoods such as oak, honeylocust, crabapple, hickory, beech, and maple trees. Like verticilium wilt, ganoderma infects trees through root or lower trunk wounding, and causes slow decline. Annual fruiting bodies can be found at the base of an infected tree or further out where roots have contracted the disease [26].

21


Invasive Plants Invasive plant species are often the primary focus when considering how to protect and enhance a particular green space, but in reality, eradicating invasive plants that have established a substantial population and range is extremely difficult [27]. Furthermore, recent studies have found that exotic trees in urban areas can still produce significant benefits toward diversity and ecosystem services [28]. The watershed forest INVASIVE contains numerous invasive plants, but the extent to which they negatively impact tree canopy cover and species diversity varies. PLANTS CAN Key invasive plant threats to the watershed forest includes tree of PROVIDE heaven, Norway maple, Japanese knotweed, bush honeysuckle, BENEFITS, BUT and a host of invasive vines, but the extent of their respective impact in the watershed is yet to be quantified. Only in the Frick OUT-COMPETE NATIVE PLANTS Park portion of the watershed is there an ongoing, organized effort to remove these species. Developing practical management goals will help promote overall watershed forest health. Primary Invasive plants of our Watershed Forest • Invasive vines – This includes wild grape (Vitis spp.), porcelain berry (Ampelopsis glandulosa var. brevipedunculata), English ivy (Hedera helix), Japanese honeysuckle (Lonicera japonica), mile-a-minute (Persicaria perfoliata), oriental bittersweet (Celastrus orbiculatus), and winter creeper (Euonymus fortunei). Vines can slowly take over shade trees as well as completely smother understory plants and young trees. Coordinating vine cutting events in woodland areas is an effective way to protect trees. • Japanese knotweed (Fallopia japonica) – Invasive herbaceous plant that forms continuous, dense understory of stalks and spreads by rhizomes, seed production, and trans-located plant material. It is tolerant of a variety of adverse conditions, difficult to manage once established, and a significant threat to riparian areas. Management includes effectively timed mechanical disruption and control of plant material [29]. • Bush honeysuckle (Lonicera maackii) – An understory shrub that forms dense understory of large individual plants in disturbed woodlands, fields, and marshes. Remove young plants by the root, or cut down larger plants in the spring and fall over some years to extinguish the plant [30]. • Tree of heaven (Ailanthus altissima) – A common invasive tree of disturbed and unmaintained sites, tree of heaven grows quickly, produces a copious amount of seeds, and readily produces root sprouts when cut back. Due to its high tolerance of urban conditions and allelopathic habit, if unmanaged, it can create tree canopy with low species diversity. To control, remove as much root as possible when handling young trees. Larger trees often require timely and repeated chemical treatments to inhibit re-sprouting [31]. • Norway maple (Acer negundo)– Pervasive tree that leafs out very early in spring and comfortably grows in dense shade. It easily outcompetes sugar maple and other native trees and establishes low diversity woodlands. Additionally, research has found that it supports less wildlife diversity. Management includes tree removal and suspending the planting of the species [32]. 22


Characteristics of Invasive Plants [33] • Ability to thrive on human-degraded sites • Rapid growth and early maturity • Aggressive reproductive strategy • Vegetative reproduction • Physically crowd out other plants • Lack of local predators, pests, or diseases

Climate Change To date, global climate change has already been disruptive by altering evaporation and precipitation patterns, accelerating ice melt, and warming oceans and soils. This has caused heat waves, droughts, extreme storms, wildfires, hurricanes, and tornadoes of varying severity across several regions of the world. We can begin to understand how local climate will change by looking at statewide projections. In Pennsylvania, many aspects of the economy, character, and quality of life will be impacted. Longer and more intense summer heat waves, reduced winter snowpack, northward shifts in the range of valuable plant and animal species, and declining yields of key agricultural crops are examples of climate change effects that are now expected over the next few decades. Without substantial changes at many levels, more public health issues will arise as Pennsylvania cities experience dramatic increases in the number of summer days over 90°F. Vulnerable populations will be at the greatest risk of heat and air pollution related stress, hindering outdoor activity for many of these individuals [34]. Extreme heat events are already a leading cause of weather-related deaths nationally [13]. Outside of advocacy at the state and federal level for policy changes toward climate action, urban forestry initiatives to plant trees, steward existing trees, and protect canopy cover are effective methods to mitigate climate change impacts locally. Trees truly are the answer by acting as a carbon sink, reducing energy use of buildings, mitigating the urban heat island effect, reducing stormwater levels, and supporting climate change-vulnerable wildlife [11, 12, 14, 22]. Pennsylvania contributes 1% of total global emissions of carbon dioxide, and of all US states, it is the third-highest in emissions from fossil-fuel sources behind Texas and California. Over time, western Pennsylvania climate could reflect conditions more indicative of southern West Virginia and Eastern Kentucky by 2040. If no action is taken to significantly alter our emissions, by 2070, our region’s climate could be more like northern Alabama. Climate conditions suitable for hardwoods such as black cherry, PENNSYLVANIA hemlock, sugar maple, and beech are projected to decline or CONTRIBUTES even vanish from the state. Additionally, bird species diversity is expected to be reduced significantly [34]. Awareness of these climate projections and how trees impact them draws attention to the critical work of making our watershed more sustainable OF GLOBAL and comfortable through urban forestry programs. CARBON

1%

EMISSIONS

23


Indicators of a Sustainable Urban Forest Assessment Tree canopy cover and public tree inventory analyses are useful to understand the physical characteristics of an urban forest, but they do not provide insight into all the components that influence how a given tree population changes over time. Criteria and indicators for strategic tree management were utilized in our planning process to understand current engagement and stewardship across the watershed forest. Twenty-four indicators in total were assessed across three broad groups: The Trees, The Stakeholders, and The Management Approach [35]. The Nine Mile Run Watershed is experiencing many positive trends toward successful urban forestry management. NMRWA is actively leading the way to establish new park and street trees in the HAS BEEN watershed utilizing adult and youth volunteers for planting and INVOLVED maintenance. NMRWA has been directly involved in planting nearly 1,000 trees in watershed communities since 2003 with TreeVitalize IN PLANTING helping fund over 60% of those. The focus on young tree care has kept 1000+ TREES alive over 80% of the trees planted since 2003 by the organization, producing an average annual mortality rate of 1.5%. Encouragingly, SINCE 2003 this watershed figure falls well below an analysis showing street tree mortality rates ranging from 3.5%-5.1% annually. Long-term monitoring will be needed to determine if this population of watershed trees exceeds the typical mean life expectancy of 19-28 years [36]. Overall, TreeVitalize Pittsburgh has planted over 1,100 trees in the watershed since 2008 in cooperation with NMRWA and civic groups.

NMRWA

! ! !! !! ! ! ! !! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! !

! ! !

! ! ! ! ! !

!

! ! ! ! ! ! ! ! ! !! ! ! ! !! ! ! ! !! !!

! !

! ! ! ! ! ! ! ! ! ! ! !! ! !! ! ! ! !! ! !! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !!! ! ! ! ! !! ! ! ! ! ! !! ! ! ! ! ! !! ! !! ! ! ! ! ! !! ! ! !!! ! ! ! ! ! !! ! ! ! ! !! ! ! !! ! !!!! ! !!! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !!! ! ! !! ! ! ! ! ! ! ! ! ! ! ! !!!!! !!! ! ! ! !! !! ! ! ! ! ! ! ! !! ! !! ! ! ! ! ! ! !! !! ! ! ! ! !! ! !! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !! !! ! !! !! ! ! !! ! ! ! ! ! !! !! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! !!! ! ! ! ! !! ! ! !! ! ! !! ! !! !! ! ! ! !!! ! ! !! ! ! ! ! ! ! ! ! !! ! ! !! ! !! !! ! ! !! ! !! ! ! !! ! ! ! ! ! ! ! ! ! ! ! ! !! ! ! ! ! ! ! ! ! ! ! ! !! ! !! ! !!! ! ! ! !!! ! ! ! !! ! ! ! ! ! !! ! ! ! ! ! ! ! !!! ! ! ! ! ! ! ! ! ! !! ! ! ! ! !! !! ! ! !! ! ! ! ! ! ! ! ! ! ! ! !! ! ! !! ! ! ! ! ! !! ! !! ! ! ! !

!

!! ! ! ! ! ! ! !! ! !

Legend NMRWA Trees Planted

! !!

! ! ! ! !!

!! !

! ! ! ! !! ! ! !!! ! !! ! ! ! !! ! ! ! !! ! ! ! ! !! !

! ! !! ! ! !

!! ! ! ! !

NMR Watershed Watershed Municipalities

! ! ! ! !! ! !! ! ! ! ! !

NMR Stream

!! !! !

NMR Culvert System 0

0.25

0.5

1 Miles

[

Esri, HERE, DeLorme, MapmyIndia, Š OpenStreetMap contributors, and the GIS user community

24


Pittsburgh Parks Conservancy, City of Pittsburgh Department of Public Works, and NMRWA have worked together since the stream restoration completion in 2006 to continue planting and stewarding areas around the stream. Additionally, the Urban EcoSteward program for the restoration area managed by NMRWA has provided a volunteer base to help manage invasive species and promote native plants and trees.

Indicators of a Sustainable Urban Forest

Assessed Performance level (Blue)

The Trees

Low

Mod.

Good

Optimal

Relative Canopy Cover Species Suitability Species Distribution Condition of Publicly-owned Trees Publicly-owned Natural Areas Native Vegetation

The Stakeholders

Public Agency Cooperation Large Private & Institutional Landholders Green Industry Cooperation Neighborhood Action Citizen-Municipality-Business Interaction Awareness of Trees as a Community Resource Watershed Cooperation Tree Inventory Canopy Assessment

The Management Approach

Watershed Management Plan Municipality-wide Funding Municipal Staffing Establishment Planning and Implementation Tree Habitat Suitability Maintenance Program: Street Trees Tree Risk Management Protection Policy Development and Enforcement Maintenance Program: Natural Areas

25


Currently, all four watershed municipalities have an active citizen tree committee and a tree ordinance, which is quite exceptional. Edgewood started a tree committee in 2017 with plans to update their ordinance and plant more street trees. Swissvale re-established a tree committee in 2015, and in 2016, they helped draft a borough tree ordinance and gained their first TreeCity USA designation from the Arbor Day Foundation. Wilkinsburg has had an active committee for over two decades and focuses on coordination of tree management in the borough. City of Pittsburgh re-established a Shade Tree Commission in 1998 to help manage the city’s tree population. Beyond assisting municipal-linked tree groups, NRMWA organizes a Tree Tender group for the watershed. The group meets quarterly for maintenance activities and learning opportunities. Finally, positive and ongoing relationships have been developed with the watershed Borough administrations of Wilkinsburg, Swissvale, and Edgewood as well as several groups in the watershed such as the Regent Square Civic Association, Wilkinsburg Community Development Corporation, Hosanna House, and various local businesses and schools to help grow and steward trees. Overall, urban forest management in the watershed has a solid foundation, but improvements can be experienced in some key areas.

The Trees Improve species diversity and the resiliency of the street tree population, and develop an ecological understanding of green spaces in the watershed.

The Stakeholders Improve coordination across watershed communities through consistent tree management practices and policies at municipal-businessresident level while also increasing appreciation for and care of trees through outreach and education.

The Management Approach Utilize tree inventory and sampling techniques to further understand the watershed forest. Additionally, improve municipal funding and staffing for tree care to help establish systematic planning of annual tree care and protection.

Urban Forest Benchmark Summary Benchmarking current conditions is important to assessing the state of the watershed forest allowing stakeholders to set goals, track progress, and adjust management over time. Positive progress has been made in tree plantings, species diversity, and stream health; however, overall canopy cover and benefits of the watershed forest have declined. The current environmental threats to the watershed forest include climate change and invasive plants, pests, and diseases. Opportunities exist to stabilize the trend of decreasing canopy cover by engaging more stakeholders, continuing annual tree planting, protecting current woodland spaces, and engaging large private and institutional landowners in better tree management. Finally, the usage of right-of-way stormwater bioswale installations is growing in the Pittsburgh area, and demonstrates the evolving applications for trees in the watershed forest, and a new approach to improving Nine Mile Run stream health.

26


Nine Mile Run Watershed Urban Forest Benchmark Summary Watershed Tree Canopy Cover

47%

Nine Mile Run Condition Nine Mile Run Ecosystem Health

C+

Street Tree Stormwater Mitigation (gal.)

11,355,000

Watershed Street Tree Values Total Tree Count

5,596

Park Landscape Tree Count

977

Trees in Good Condition

32%

2005 Species over 10% of Population

3

2017 Species over 10% of Population

2

Annual Benefits of Street Tree Population Total Value of Benefits($)

$816,480

Benefits($) per tree

$146

Watershed Urban Forest Metrics Sustainable Urban Forest Evaluation: Assessed Performance Level

Moderate

Active Municipal Tree Committees

4 of 4

Wilkinsburg Urban Forest Benchmark Summary Tree Canopy Cover

41.9%

Street Tree Values Total Tree Count

1677

Park Landscape Tree Count

196

Trees in Good Condition

24%

2005 Species over 10% of Population

3

2017 Species over 10% of Population

2

Benefits of Street Tree Population Total Value of Benefits($)

$251,125

Benefits($) per tree

$149.75

Benefits($) per Capita

$16.11

Swissvale Urban Forest Benchmark Summary Tree Canopy Cover

35.8%

Street Tree Values Total Tree Count

669

Park Landscape Tree Count

66

Trees in Good Condition

23%

2005 Species over 10% of Population

3

2017 Species over 10% of Population

2

Benefits of Street Tree Population Total Value of Benefits($)

$103,530

Benefits($) per tree

$154.75

Benefits($) per Capita

$11.53

Edgewood Urban Forest Benchmark Summary Tree Canopy Cover

50.5%

Street Tree Values Total Tree Count

691

Park Landscape Tree Count

59

Trees in Good Condition

14%

2005 Species over 10% of Population

3

2017 Species over 10% of Population

3

Benefits of Street Tree Population Total Value of Benefits($)

$129,005

Benefits($) per tree

$186.69

Benefits($) per Capita

$42.45

27


28


VISION F OR THE WATE R S HE D F O R E S T Outreach Overview

In the early months of 2017, NMRWA staff and the plan’s steering committee developed an outreach strategy to educate residents on the planning effort as well as collect valuable information from watershed residents about the watershed forest in their respective communities through surveys and conversations. Additionally, we interviewed steering committee members and representatives of other stakeholder groups to understand their unique perspectives of the watershed forest. Between May and September of 2017, we used active and passive outreach methods to identify the needs and opinions of residents and stakeholders.

There is a wonderful, huge, and very old mulberry in our backyard. I ADORE this tree. We’ve lived in our apartment for 11 years and I am always afraid that my landlord will cut it down…I hope he leaves it there. It makes living in the City a lot easier as a country girl. It’s beautiful and the squirrels and birds love it!

~ Crystal

29


Outreach Goals • Assess stakeholder and watershed resident comprehension of tree benefits • Educate about threats and challenges to the watershed forest • Increase participation in NMRWA’s Urban Forestry program • Identify community needs and concerns related to watershed trees • Identify outlets for collaboration across watershed communities • Build a cultural database of stories related to watershed trees

Resident Survey Results Goals for surveying were to understand resident comprehension of tree benefits, identify problems currently experienced with trees, assess involvement, identify needs, and begin to build a database of significant watershed trees through ‘tree stories’. Watershed residents submitted 244 surveys with 94 coming from Wilkinsburg residents, 58 from Pittsburgh residents, 55 from Swissvale residents, and 32 from Edgewood residents. While the resident survey included fourteen questions (Appendix), five questions produced the most noteworthy results for consideration. The analysis of survey data showed that residents find the aesthetic quality, air quality improvements, shade, wildlife support, and stormwater benefit of watershed trees to be very valuable. Alternatively, residents identified infrastructure damage (Sidewalk lift, roots in underground pipes, electrical line conflicts) due to trees as very important. While this result is not surprising, the lack of trees and canopy as an issue rated nearly as high as the noted infrastructure challenges, which is encouraging from a public appreciation perspective. When indentifying tree-related neighborhood needs, better management and care of street trees, more trees, and more community education about trees were the top three responses. The more trees vote further supports the respondent’s identification of the lack of canopy as an issue. The top three ways in which respondents would enjoy becoming involved in tree-related activities were by planting a tree, attending education programs related to trees, and volunteering at a tree care event. The need for more educational opportunities is identified here again, and when coupled with a survey question showing that the majority of resident property owners are unsure of their responsibilities toward street trees; the need for more creative and effective outlets to disseminate information becomes apparent. Public awareness and appreciation of the benefits of trees does not appear to be a major problem, but the knowledge needed to confidently approach various tree-related challenges or stewardship activities appears to be greatly desired. Stakeholder Interview Results Interviews were designed to assess the benefits and challenges of trees, the management needs, and the involvement in tree-related activities by watershed stakeholder groups. Interviewees represented municipal staff, elected officials, tree committee volunteers, and other nonprofit organizations. Nineteen stakeholder interviews were conducted. The top benefits of trees identified by the stakeholders were aesthetics, shade, environmental benefits, and neighborhood walkability while the top problems that need to be addressed were maintenance of trees, infrastructure damage, lack of resident

30


education, and liability issues. Immediately, the interview results show similarities to resident responses toward tree benefits, issues, and outreach needs. Corroboration with resident survey results continued to strengthen as improved funding of maintenance, educational outreach, and quality data for planning were identified as important management needs. Furthermore, resources (time, money, and staff) and appreciation of trees were noted as key barriers to increasing tree maintenance. Finally, an increase in tree planting and concern for the environment were two positive trends that stakeholders have witnessed within the watershed forest. Conversely, invasive pests and diseases as well as the uncertainty around state and federal support for environmental initiatives were identified as negative trends impacting watershed trees. Considering the full results of the resident surveys and stakeholder interviews, a lack of tree-related knowledge and the resources to engage in proper stewardship are noteworthy threats to the urban forest despite the wider understanding of how trees benefit resident quality of life. Municipal tree programs are generally lacking resources, leading to public trees in poor condition and a reduction in the environmental benefits KEY VALUES TO provided [9]. Property owners and contractors involved THE COMMUNITY: in landscaping, excavating, or sidewalk replacement indiscriminately sever tree roots without regard to the impact AESTHETICS, on adjacent trees which can cause declining health and SHADE, AND premature death [37]. Finally, trees are often planted too ENVIRONMENTAL deeply creating chronic stress conditions that are difficult to BENEFITS remediate after only a few years [38]. These awareness-based issues create challenges to maintaining and growing a quality watershed forest in the long term. With the outreach data submitted and analyzed and the benefits of urban trees understood, we were able to establish a working goal for the NMR Watershed forest. A Vision for the Nine Mile Run Watershed Forest

The Nine Mile Run Watershed forest is essential to the quality of life of residents as well as a key feature of sustainable stormwater management. Through diverse partners and educational outreach, watershed trees will be properly established in new locations, resilient to threats, and well-maintained for positive ecological, social, and economic benefits. This vision will be achieved through programs and initiatives implemented in four categories: 1. Watershed 2. Community Spaces 3. Residential 4. Commercial

31


32


RECOMMENDATI O NS F O R TH E NI NE MI L E RU N WATERSHED F O R E S T Improving the watershed forest requires a coordinated and informed effort by supporting stakeholders. Twenty recommendations with related action items were outlined by the plan steering committee and NMRWA staff based on an interpreted synthesis of outreach results, data analysis, and best practices. The recommendations are crafted to address challenges in areas such as tree planting, tree preservation, outreach, and education, but ultimately, they support an over-arching goal of stabilizing and reversing the current trend of watershed tree canopy loss. Robust canopy is important to watershed ecosystem health by supporting wildlife, improving air quality, cleaning stormwater, and reducing runoff. Additionally, well-planned and distributed trees improve the quality of life of residents and are an essential tool to help mitigate climate change. To best address this goal across the watershed landscape, recommendations were divided into four categories: Watershed, Community Spaces, Residential, and Commercial.

I would LOVE for Pittsburgh to have an edible forest with lots of fruit trees, like the one in Asheville. I would be very happy to be part of an initiative like that. There are so many vacant lots in Wilkinsburg that we could turn into edible forests, which could also be centers for education and community empowerment.

~ Arianna 33


Watershed

Recommendations

Watershed level recommendations address broad urban forestry and tree management needs that transcend political boundaries and land use designations.

1. Increase public engagement to promote appreciation and understanding of trees The term ‘urban forest’ is still not a well understood concept for residents and civic leaders, creating a void between an individual’s or organization’s efforts toward tree care on their own property and an understanding of how that contributes to the broader picture of community tree benefits [9]. The reasons to not want to plant trees or care for them can vary widely, but in general, people can clearly identify why trees are important to the landscape [39]. Watershed residents have identified the need for more community education, and expressed an interest in attending educational workshops. Stakeholder interviews further supported this need for increased public engagement. Currently, information on the benefits of urban trees to the watershed is isolated to online platforms, but print newsletters of watershed boroughs or NMRWA are utilized to highlight tree-related projects. Outreach and messaging could improve by developing a coordinated effort among watershed stakeholders. Finding creative ways to improve access to tree-related information is essential to building a consensus on the benefits of investing in trees. Action items include: a. Assemble a ‘best practices’ tool-kit targeted for strategic stakeholders and new development (ex. Businesses, large land owners, institutions, schools). b. Coordinate educational workshops on specific tree-related topics. c. Educate on division of ownership and maintenance responsibilities between property owner and municipality. d. Post urban forest statistics in high traffic public areas. e. Identify remarkable trees in the watershed with informative signs. f. Create a self-guided walking tour spread around the watershed that visits remarkable trees and green spaces on community property and along streets. g. Make street and park tree data publicly available online and easy to access. h. Incorporate signage for new tree plantings to identify funders and how to participate. i. Educate health providers about the benefits of green space to patient wellness. 34


2. Support watershed tree committees and promote communication and collaboration among them when applicable. Municipal tree committees are commonly made up of civic-minded residents, municipal officials, and experts, and their role is outlined by a guiding resolution. They are helpful by assisting with community outreach, management decisions, and policy updates for municipal staff. Given the differences from borough to borough on what their respective shade tree committees are working on, opportunities to learn from one another and replicate success can be realized through inter-committee meetings and information sharing. In addition to regular participation at monthly meetings and providing technical guidance, cultivating communication between committees is important to keeping them active. Action items include: a. Advise committees on tree initiatives, and involve them in NMRWA urban forestry projects. b. Convene an annual meeting of municipal tree committees to share and discuss projects to learn from one another. c. Assist in the development of proactive borough tree management plans. d. Coordinate events (such as Arbor Day) across watershed to increase awareness.

3. Develop and implement annual watershed tree planting goals. An estimated 1,500 to 2,000 trees were lost in the watershed each year between 2010 and 2015, with much of the individual tree loss scattered across neighborhoods and parcels. Amalgamated, the canopy of those lost trees outpaced the gains in the same time period. A declining tree population means increased stormwater runoff, less shade, increased home and office energy use, less wildlife habitat, and ultimately, a reduction in public health and aesthetic quality of the community [40]. Furthermore, Tree Pittsburgh’s county-wide canopy analysis indicates that the declining trend might continue if the primary forces behind the net loss continue [7]. Resident surveys identified a lack of canopy as one of the top issues presently experienced in their neighborhood. Furthermore, the desire for more trees was one of the top treerelated needs identified by residents. Using the estimate of trees lost per year and analyzing the spatial distribution of public trees and canopy, annual tree planting goals can be developed. Balancing what is practical versus what is ideal is the challenge when setting tree planting goals. Participation, funding, and the rate of mature shade tree loss are factors to consider as well.

35


Action items include: a. Utilize available data to set tree planting goals. b. Plant street and park trees annually to address tree mortality and hazard tree removal. c. Incentivize tree planting by residential, commercial, and institutional property owners. d. Select species and sites to efficiently maximize canopy growth; always plant large shade trees when the space allows it. e. Monitor and manage invasive plant or pest populations that inhibit tree canopy establishment or create ecosystems of low diversity. f. Monitor progress of tree planting efforts by partnering with other groups to monitor canopy changes over time.

4. Provide equitable urban forest benefits across the watershed. Chronic stress is often experienced disproportionately in low-resource communities, characterized by poor access to housing, nutritious food, job opportunities, and health care. Additionally, research has demonstrated that inequitable access to green space contributes to these public health disparities and inequalities. A healthy and wellplanned street and park tree population contributes to quality public spaces, and is not only a primary focus of urban forestry initiatives, but also, of community revitalization, neighborhood walkability, and youth engagement projects [41, 42]. The watershed contains neighborhoods with a range of socioeconomic conditions that can benefit from equitably planned urban canopies. In general, the greatest density of high value residential properties is found directly adjacent to the largest green space in the watershed; Frick Park and The Homewood Cemetery. Moving out further into the upper watershed, property values tend to decrease. Challenges in outreach have been experienced during past initiatives when trying to bring urban forest resources to areas of high rental properties and low-income. 62% of properties in Wilkinsburg Borough alone are renter occupied. According to U.S. Census data, the median household income for Wilkinsburg, Swissvale, and Edgewood is $33,905, $40,391, and $73,250 respectively (median income of Allegheny County is $54,357). Furthermore, persons in poverty in Wilkinsburg and Legend Swissvale are 24.1% and Property Values 0-50k 17.5% respectively (11.5% for 50-100k Allegheny County). Thoughtful 100-150k targeting of programs, and 150-200k 200-300k more importantly, a significant 300K+ time investment are critical to NMR Watershed ensuring that urban forestry Watershed Municipalities initiatives are equitable in their NMR Stream NMR Culvert System distribution, and it is important in gaining support and making progress in the most challenging areas. 0

0.25

0.5

1 Miles

[

Esri, HERE, DeLorme, MapmyIndia, Š OpenStreetMap contributors, and the GIS user community, Esri, HERE, MapmyIndia, Š OpenStreetMap contributors, and the GIS user community

36


Action items include: a. Build relationships, trust, and participation through multi-year initiatives in underserved neighborhoods. b. Prioritize tree plantings in underserved, low-income, or low percent canopy cover areas. c. Balance street tree planting, maintenance, and preservation efforts between neighborhoods with few right-of-way trees and areas in need of proactive replanting to address existing and future mature tree loss. d. Plant and protect trees along heavily used pedestrian and bicycle routes to mitigate daily users’ exposure to air pollutants.

5. Diversify, leverage, and increase funding for NMRWA urban forestry programs. For non-profit urban and community forestry, funding effective programs often requires a patchwork of sources. Funding can come from a range of entities that include state or federal grants, corporate sponsorships, private foundation grants, and donations. Inkind services donated to specific projects should not be overlooked either. Developing beneficial relationships with other non-profit organizations, municipal public works staff, and local contractors can help meet program goals when budgets are tight. Understanding how to target messaging to specific groups as well as utilizing research and statistics for justification are important first steps in diversifying partners. In a survey of northeastern Pennsylvania municipalities, only 21% of respondents felt that their tree program received enough funding to effectively function [9]. Similarly, interviews with municipal stakeholders revealed a need for resources to do more. Since the conclusion of the Wilkinsburg TreeVitalize 500 Tree Initiative in 2013, NMRWA has installed only 150 trees in the last four years. While tree planting is only one feature of an effective urban forestry program, the trend indicates funding challenges in all areas.

Action items include: a. Pursue corporate sponsors for tree planting or care. b. Identify and secure resources that can improve public tree maintenance. c. Identify opportunities to pair research partnerships with urban forestry projects.

37


6. Increase participation, diversity, and leadership within the watershed forest community. Volunteers are an important resource in growing the next generation of street and park trees, and have been utilized since the early days of NMRWA. Reaching out to local organizations such as Wilkinsburg Youth Project, Pittsburgh Job Corps, and college student groups has also been very helpful in addressing larger maintenance efforts. For even more targeted maintenance of street and park trees, the Tree Tender and Urban Ecosteward programs have been active in the watershed. To date, Tree Pittsburgh has trained over 1,800 Allegheny County residents as Tree Tenders who help properly plant, mulch, and prune young trees at a huge cost saving to municipal street tree programs. Over 60 of those Tree Tenders are in Wilkinsburg, Swissvale, or Edgewood, and in 2017, the NMR Watershed Tree Tender group had 10 active members. NMRWA has utilized on average 190 youth and adult volunteers for 487 hours of young tree maintenance work annually since 2013. The resident survey analysis indicates that people are engaging in tree related activities and are interested in volunteer opportunities. Currently, much of the volunteer time is donated by a small number of people, and some events draw more interest than others. To combat turnover and increase participation, improved outreach and cultivation for a more robust queue of volunteers and groups is needed to address mounting tree maintenance work. Action items include: a. Communicate the results and recommendations of the Watershed Forest Master Plan. b. Develop multi-year partnerships with local civic and youth groups to develop community awareness and action for tree planting projects and young tree maintenance. c. Promote Tree Tender program, and coordinate a Watershed Tree Tender group. d. Develop an adopt-a-tree or block program for tree maintenance. e. Develop management plans and utilize Urban EcoSteward program for upper watershed natural areas. f. Develop a tree hanger advertising who has performed maintenance for a tree and how to get involved.

38


7. Increase the usage of stormwater tree pits and bioswales for strategic stormwater management in the public right-of-way. Since 2008, Pittsburgh and the surrounding region have been under a consent decree by the US Environmental Protection Agency to reduce sewer overflows. The stormwater system is often insufficient during storms resulting in runoff combining with sewage to flow into the rivers as well as causing basement backups and localized flooding. NMRWA is a founding partner of the Clean Rivers Campaign that aims to build awareness about the stormwater and sewer issues, and advocate for affordable green solutions that deliver multiple community benefits. Recent stormwater infrastructure projects in the Pittsburgh area have utilized roadside bioswales that include trees to advance stormwater management to a new level. Stormwater can contain oil, grease, metals, and coolants from vehicles as well as sediment, fertilizers, pesticides, and household chemicals from landscapes. Bioswales host a diverse palette of plants, but incorporating trees into these installations can improve ecological results. A recent study found that trees included in green stormwater systems are moving significant amounts of water from bioswale systems back into the atmosphere [43]. NMRWA has recently contributed to this effort. In 2015, the Rosedale Runoff Reduction Project (RRRP) was initiated to start addressing a combined sewer overflow (PWSA 1071-OF) that discharges an average of 25 million gallons of sewage polluted stormwater into NMR every year. Two major features of the program were to install large green stormwater infrastructure facilities as well as smaller stormwater tree pits. By the end of 2016, two major stormwater facilities were constructed and six stormwater tree pits installed. These projects were the first of their kind for NMRWA, and are providing valuable insight into the effectiveness and maintenance needs for such installations in our region. Roadside bioswales and stormwater street tree pits are new ways in which ecosystem services are being incorporated into urban areas, and not only constitute an important method of reducing combined sewer overflows to NMR, but also enhance the watershed forest.

Action items include: a. Analyze stormwater flow patterns and areas of significant accumulation in watershed. b. Identify strategic locations to install stormwater tree pits and bioswales. c. Work with municipalities to standardize design, implementation, and maintenance of green stormwater facilities in the right-of-way.

39


8. Continue to work toward species diversity in public spaces to ensure that no single species represents more than 10% of the population, no genus represents more than 20% of the population, and no family represents more than 30% of the population. For decades, the number of tree species utilized along our urban streets has been quite low; usually, trees that easily thrived in the toughest urban environments were planted. Nationally, elm and ash are two such examples that created attractive uniformity, but Dutch elm disease and the more recent outbreak of emerald ash borer have had a devastating effect on elm and ash trees due to their abundant use as street trees. These pest outbreaks spread and killed trees quickly, significantly altering the character of neighborhoods and the benefits experienced. Drawing wisdom from these experiences, urban forestry leaders have had to rethink how to select trees to insulate public tree populations from unknown future threats. To reduce the enormous financial burden associated with large scale hazard tree removal and the immediate impact to quality of life, urban forestry practitioners now select and design tree planting projects for species diversity [44]. Furthermore, certain tree species are suited to provide certain benefits more effectively. Planting for a variety of species promotes a diversity of benefits. The watershed as a whole, as well as Wilkinsburg, Swissvale, and Edgewood, all have two species that represent more than 10% of the respective street tree populations (primarily pin oak and London planetree), but when comparing street tree composition to the 2005 data, species diversity has improved. Time and the continued practice and encouragement of species diversification in planting projects will continue to produce positive results in species composition. Action items include: a. Locate and select non-invasive trees properly for species diversity and resiliency in planting projects. b. Support native wildlife by planting native trees and shrubs whenever possible. c. Utilize and periodically update watershed tree inventory to inform species selections. d. Prioritize planting of evergreens for year round stormwater and air pollutant management where possible. e. Encourage municipalities to design and adopt policies for how development plans address species diversity, and to enforce those policies.

40


9. Work with boroughs on policy updates that impact tree canopy cover. When street right-of-way and publicly-owned land is removed from a land use map, it becomes apparent that so much of where it is possible to grow canopy cover in the urban forest is found on privately-owned land. One of the primary forces affecting an urban forest’s structure and sustainability is land use policy and land use change [45]. In addition, the Indicators of a Sustainable Urban Forest worksheet identified public trees as the only area currently under tree protection ordinances, and identified large private and institutional landowners as a group for more targeted coordination. Municipal authorities can utilize non-regulatory (comprehensive plans, land owner education, etc.) and regulatory tools (zoning and subdivision ordinances, transfer of development rights, etc.) to address how tree canopy cover is protected in a given area and how trees are addressed during development.

Action items include: a. Recognize the urban forest as municipal infrastructure. b. Work with partners to identify and preserve quality trees during vacant property demolition, land clearing, or redevelopment of existing parcels/structures. c. Identify important watershed green spaces for tree canopy retention, and utilize tools to protect existing mature trees. d. Assist municipalities in the enforcement of tree protection and zoning ordinances. e. Seek out and engage with small and large development projects to share tree canopy goals and metrics. f. Engage in municipal planning efforts that impact canopy cover growth or loss. g. Work with municipalities to create zoning code that favors canopy retention and growth. h. Develop a resolution for municipalities and other civic groups to adopt to unify a vision that supports the effort to increase canopy cover.

41


10. Coordinate borough training opportunities focusing on how to address common arboriculture and urban forestry challenges. Outside of the City of Pittsburgh’s Forestry Division, watershed municipalities do not dedicate staff toward street or park tree maintenance regularly. Encouragingly, the watershed boroughs are among the 18% of Pennsylvania boroughs that have some form of a street tree program [46]. Wilkinsburg, Swissvale, and Edgewood public works all have the basic resources to address reactionary tree activities such as fallen or broken branches and small removals, but largely; they all utilize arborist service contractors annually to conduct most tree pruning and removal work. Residents and stakeholders both identified maintenance as a problem with street trees which is due to time and resources needed for adequate attention. A well-funded tree program is often low on the priority list of municipal responsibilities, and even more so for financially-distressed municipalities [46]. To build capacity with existing resources, supplemental training and education of borough staff can help increase appreciation of the street tree resource and understanding of what can be accomplished in-house to support a safe and healthy population.

Action items include: a. Train borough staff on how to protect street trees during right-of-way maintenance. b. Educate borough staff on how to best engage the public to address common tree and other utility infrastructure conflicts. c. Train municipal staff on pruning work that can be achieved without an outside contractor, and how to properly prune. d. Collaborate on maintaining, updating, and utilizing tree inventory data.

42


Community Space Recommendations

Community space recommendations address the tree management needs in public parks, playgrounds, and community gardens as well as institutional properties such as schools, churches, and cemeteries.

1.Continue stewardship of Nine Mile Run restoration area to promote a diverse and resilient natural public space. For NMRWA, the stream is the most widely identifiable feature of the organization’s programming. Prior to the restoration, the stream was a nearly lifeless ecosystem due to historic pollution from industry, excess stormwater runoff due to urban development, and failing sewer infrastructure in the surrounding watershed. After the ecosystem restoration in 2006, parcels of the entire restoration area were assigned to Urban EcoSteward volunteers to help preserve the native plants that had replaced invasives as part of the restoration effort. Water quality monitoring and evaluation has also been important to understanding and reporting progress toward stream health. Over the 11 years since the restoration, the area has developed the natural and functional aesthetic envisioned many years ago. Furthermore, tree canopy around the NMR stream has increased significantly, as has overall stream health since 2006. This progress is worth celebrating, but challenges still exist with invasive plants returning, reducing species diversity and suppressing trees in certain areas.

Action items include: a. Continue to coordinate Urban EcoStewards in the restoration area to promote native plant regeneration. b. Coordinate with partners to promote, improve, and expand the Urban EcoSteward program. c. Assist with the management of ecological problem areas in the restoration area. d. Identify opportunities for and collaborate on native tree plantings for continued canopy regeneration. e. Continue to monitor water quality in Frick Park to assess linkages of urban forestry projects to changes in Nine Mile Run flow and water quality.

43


2. Support initiatives to promote and enhance park spaces. In recent decades, non-profit and community groups have championed the public benefit of investing in urban parks, and have successfully turned relevant research into implementable projects [47]. Green spaces of any size are valuable to overall community health as they allow opportunities for youth and adult outdoor recreation and exercise, restorative connection with nature, and social engagement. Parks are even considered beneficial by those who do not utilize the spaces personally [48].

Frick Park is a major regional park in the City of Pittsburgh, and is a substantial feature of the watershed forest, drawing users from neighborhoods across the city and beyond. Additionally, the boroughs of the watershed contain neighborhood parks of various sizes and amenities. Parks are valuable to watersheds and urban forests as they constitute a landform that is usually reliably stable in tree canopy cover. Involvement in efforts to improve and manage parks will help ensure that these spaces continue to benefit residents and the environment.

Action items include: a. Enhance access to parks and green spaces. b. Identify opportunities to plant trees in parks to promote species diversity and fruit tree establishment. c. Install trees to shade playgrounds. d. Produce a benefit analysis for each watershed park.

3. Educate officials and neighborhoods about the value of vacant lot green spaces. Blighted housing and vacant lots are a significant problem and topic of discussion in some areas of the watershed. A 2014 field-verified assessment found over 700 vacant properties in Wilkinsburg. For the ones that contain unsafe dwellings, demolition eventually occurs which returns the parcel back to green space, albeit, significantly altered. The fate of vacant property can vary. It can be acquired by an adjacent property owner, reserved for future development, or simply abandoned for nature to take over. Successful examples exist in the watershed where vacant lots were re-envisioned for public use. In Wilkinsburg, the Hamnett Place and Stone Soup community gardens currently sit on former housing lots. Furthermore, Hosanna House, a community non-profit support center, acquired vacant lots adjacent to their property and improved the landscape with seating, flower beds, and trees. As more interest builds toward vacant lot repurposing, NMRWA should work with partners to support uses that positively impact the community and watershed.

44


Action items include: a. Work with partners to map and identify key vacant parcels for municipalities or groups to gain ownership of and transition to community/neighborhood use. b. Identify ideal vacant lots for community gardens and fruit orchards. c. Identify vacant lots where growing tree canopy is a good long-term use. d. Assist in developing management plans specific to vacant lot repurposing.

4. Outreach to institutional property owners to educate and implement tree management projects. Institutional properties such as schools, cemeteries, and libraries are often located on larger parcels of land yielding an opportunity to meet tree planting or canopy goals. The watershed contains many schools, and during the Wilkinsburg TreeVitalize 500 Tree Initiative, 20% of trees planted were on or around the campuses of the two elementary schools in the borough. When we group school properties in with the abundant churches, large cemeteries, and borough libraries in the watershed, the value of targeting tree initiatives to them becomes apparent. But simply planting trees around schools or churches is not enough. The excitement of tree planting can quickly sour when property maintenance activities routinely damage young trees because of a lack of involvement and understanding. Educating property maintenance staff on how to support healthy trees is essential to the success of young trees. Programs to grow and support the tree populations on institutional lands are beneficial to the general public, and can make broader aesthetic impact when compared to parcel to parcel street trees.

Action items include: a. Assist The Homewood Cemetery in their effort to maintain their Level I Arboretum status. b. Utilize school campus trees to educate students on the importance of trees; pairing educational programs with tree planting and maintenance. c. Connect church congregations with greening opportunities in their neighborhood. d. Help identify resources to fund long-term maintenance. e. Encourage and help with assessments of park trees to reduce hazard to users. f. Include an ISA Certified Arborist consultant during park improvement projects to protect and incorporate trees. g. Advocate for trails in wooded, non-developed green spaces to improve connectivity. h. Utilize park spaces and Nine Mile Run restoration area to host tree identification walks.

45


Residential Recommendations

Residential level recommendations address the tree management needs for residential areas and homeowners. 1. Educate homeowners on importance of trees in the landscape. Due to a high volume of rooting space as well as heightened personal care and protection, residential landscape trees have a greater likelihood of maturing into healthy, high value specimens. But, it is important to recognize that most homeowners are not experts on how to maintain and prevent damage to their trees, and may need regular guidance to make confident decisions. It is not difficult to negatively impact a tree’s health. For instance, installing a tree too deeply in the ground, poor pruning decisions, and severing roots too close to the tree all can significantly reduce a tree’s vigor and overall life expectancy. Taking simple steps to mitigate costly issues and grow quality trees around a home can increase property values by an estimated 11%. Building awareness and knowledge in residential areas is an important component in growing and protecting overall tree canopy [15].

Purchased my home in 2012 BECAUSE of the trees.... especially the one in my front yard!

~ Melissa

Action items include: a. Educate homeowners on the resources available to advise them about tree care and how to spot risks to tree health as well as what professional certifications to look for when hiring an arborist consultant, via door hangers, newsletters, and digital media. b. Educate homeowners on how to properly select, locate, and install trees. c. Assemble tool kit for what residents can do to address infrastructure issues while protecting trees. d. Utilize an internet-based platform to address tree-related questions from residents. e. Hold small neighborhood tree tending sessions advertised by local area signage and groups. f.

Utilize Arbor Day to educate residents on importance of trees.

g. Develop neighborhood-based initiatives and solutions to urban forestry issues.

46


2. Provide subsidized trees for homeowners to plant on their property. In order for tree cover to be sustained and increased in the watershed, residential land will play a key role, as 44% of the existing watershed tree canopy and 45% of the possible areas to grow tree canopy reside on residential land [8]. Additionally, there are many residential areas in the watershed where street trees, defined as a tree between the curb and sidewalk, simply will not work when utilizing current specifications for minimum tree pit size. In these particular neighborhoods, other means of incorporating trees must be explored. For goals aimed at enhancing street aesthetics and growing canopy over impervious surfaces, a community could engage in a front yard tree planting initiative. If more general distribution is desired, models such as TreePhilly’s yard tree giveaway could be developed and implemented. Since 2012, they have given away over 2,000 trees annually to homeowners in Philadelphia [49].

Action items include: a. Target outreach to homeowners in areas with no tree pits or insufficient sidewalk space, to encourage front yard plantings. b. Design and implement a subsidized private landscape tree program with “right tree, right place� information and planting instructions. c. Help municipalities establish a program to provide residents access to free mulch/ wood chips for street and landscape trees. d. Provide volunteer support for residents who want to plant trees, but have physical limitations.

3. Encourage the use of alternative sidewalk materials and design to address sidewalk lift and preserve healthy street trees. Street trees and their placement within the right-of-way have often created conflicts with other important infrastructure features. Power outages, invaded pipes, and heaved sidewalks have long frustrated property owners and municipalities. In the Pittsburgh area, improvements in siting and selecting street trees will hopefully limit these conflicts in the future, but much work is still required currently to address these issues without losing valuable mature street trees prematurely. Three out of the top four tree issues identified in resident surveys were related to infrastructure conflicts. Over the years, NMRWA has noted the conflict between trees and pedestrian walkways in watershed neighborhoods. To raise awareness and provide solutions, demonstration projects were utilized to highlight alternative materials and designs. In 2012, a porous rubber aggregate was used to replace a damaged sidewalk up against a street tree in a non-root damaging method. Later in 2013, asphalt and a curved design were utilized together to create a safe sidewalk adjacent to a very large street tree. Demonstrating and providing tools to address sidewalk lift while retaining adjacent trees is essential to cultivating support and participation in tree planting initiatives.

47


Action items include: a. Assess issue of sidewalk lift around the watershed. b. Prioritize areas with significant sidewalk lift and high pedestrian use for demonstration projects. c. Help municipalities develop incentives for using alternative permeable materials for sidewalk reconstruction. d. Encourage sidewalk layout that creates space for street trees. e. Encourage sidewalk construction techniques that have been shown to minimize tree root conflicts [50]. f. Select the proper species for sites close to sidewalks that will avoid damaging conflicts. g. Plant larger growing trees in front yard spaces.

Commercial Recommendations Commercial level recommendations address highly developed areas of the watershed such as business districts, major transportation routes, and industrial sites.

1.Increase participation of businesses in street tree care. Areas of retail and commerce are often highly developed and lack trees to soften the landscape. The urban heat island effect is more prevalent and impacts shoppers in such areas due to the high amount of cement, asphalt, and other heat-absorbing surfaces. Incorporating trees to shade impervious surfaces can help reduce radiant heat, but building support for trees in business districts can be difficult. Trees are often derided for blocking store signs, creating debris, and requiring unwanted maintenance costs which could potentially impact a business owner’s bottom line. While there are several factors that contribute to the desirability of a particular business area, well-planned landscapes with trees are important to visitor perceptions, and research shows that patrons are willing to pay as much as 9-12% more for goods and services in such areas [51]. 48


From the Edgewood Towne Centre to older business districts like the ones found in Wilkinsburg and Swissvale, the watershed similarly has low tree canopy cover in these areas. Street trees have been incorporated in some business districts, such as Penn Avenue in Wilkinsburg, but health varies from tree to tree, requiring annual attention to maintenance and replacement to promote aesthetic quality and comfort. Communicating benefits and incentivizing participation among business owners are important components to long-term tree health.

Action items include: a. Educate business and property owners about how trees impact businesses, utilizing statistics, mythbusting, and branding. b. Create renderings or visuals of what a business could look like with a properly sited tree, and how trees can be incorporated when re-designing a business front faรงade. c. Develop partnerships to offer a tree care package (labor, supplies, etc.) that a local business can purchase for trees near their location. d. Encourage tree pit beautification to compliment trees and engage businesses in tree pit stewardship and watering during the summer months. e. Educate businesses on sidewalk de-icing products and practices that are friendly to trees and plants. f. Partner with community and economic development groups to address maintenance needs.

2. Identify projects to incorporate trees into watershed parcels with high amounts of impervious surface. To address excessive runoff, urban heat island effect, and air quality issues related to areas of high impervious surface, tree planting projects that are targeted in these areas for long-term canopy establishment are essential to quality of life both locally and regionally. Identifying possible projects usually is not the difficult piece of a program, but understanding long-term use goals and securing funding to design and build for effective tree growth is. The Edgewood Towne Centre is the most conspicuous example of a failure to design for successful tree growth. When constructed, trees were abundantly incorporated into the large parking area, but available soil volume and water available to the trees was very low resulting in a population of small, highly stressed, and poor-looking trees that are a fraction of their envisioned size. Successful design models exist for trees in high impervious areas [52]. Advocating for enhanced tree installation designs and support of their implementation is needed to realize progress.

49


Action items include: a. Assess long-term use goals for high impervious parcels. b. Help municipalities update and enforce zoning codes to require landscape trees in parking lots. c. Encourage and help design specifications that increase the volume of un-compacted soil for trees in highly developed areas. d. Identify opportunities to establish trees or other natural landscapes adjacent to major transportation routes. e. Incorporate trees into road projects (street or island trees) for cost effectiveness.

3. Engage utility providers on how they can help promote a healthy urban forest. Electrical, gas, and water line repairs and improvements often are not performed in a manner that is complementary to the preservation of adjacent trees. Urban foresters have adjusted their protocols when planning street trees to mitigate conflicts by planting small maturing trees under electrical lines and locating trees a safe distance away from underground pipes. Compromises and support for preventing unnecessary damage to trees from the utility providers is unevenly applied. For instance, vegetation management teams for electrical line clearance are inconsistent in the quality of their pruning practices, and underground gas utility work often severs large roots of trees unnecessarily when replacing lines, causing eventual mortality. While positive relationships exist with utility providers in the watershed, more communication and partnering is important to support the health and longevity of street trees.

Action items include: a. Advocate and provide guidance for tree protection during major infrastructure work. b. Educate on how root damage impacts tree health and safety. c. Provide training on how to work around street trees to limit damage. d. Find and engage with spaces owned by utility companies to grow tree canopy.

Recommendations Summary: Implementation of an effective urban forestry program is challenging at any scale. NMRWA aims to be a model for tree management in urban watersheds. As cities plan for environmental resiliency against climate change and address local quality of life issues, linking solutions with ecological improvements will yield more robust public health benefits. The summarized recommendations show the frequency of engagement and partners involved in each initiative as they vary in scale and likely require a collection of partners. Finally, all action items should be conducted in a manner that clearly establishes the outreach, implementation, and maintenance components necessary for success.

50


M ON ITORING PROGRE S S Recognizing the watershed forest as a natural resource for public good, NMRWA will utilize an adaptive management approach. This involves exploring alternative ways to meet management objectives, predicting the outcomes of alternatives based on our current state of knowledge, implementing one or more of these alternatives, monitoring to learn about the impacts of management actions, and then using the results to update our knowledge and adjust management actions. Thus, the master plan will be monitored, evaluated against benchmarks, and revised when necessary. Monitor As recommendations and their respective action items are prioritized and implemented, metrics of expected outcomes will be developed for monitoring progress, and ultimately, the effectiveness of the approach. An annual summary of quantifiable metrics will be prepared to assess and communicate results.

There is a massive oak tree in my neighbor’s back yard that has a hawk’s nest in it. We had a good view of the hawk family’s progress through spring and summer, from mating to seeing the young ones learn to fly.

~ Earl

51


Evaluate Watershed forest benchmarks reported in 2018 will be evaluated against an updated resource analysis every 5 years. Coupled with monitoring data, adjustments to management actions will be well informed and adapted to meet current conditions. While recommendations will not likely change, the outlined action items might in this model.

Revise The Watershed Forest Master Plan will guide NMRWA’s tree-related programming for many years to come, and will be the basis for selecting which projects to pursue. Resource analysis updates and implementation adjustments will ensure that the plan remains relevant, but time or circumstance will determine whether or when a complete master plan revision is required. The plan should be revised and updated every 10-15 years or in situations that drastically alter the state of the urban forest. For example, the introduction of a highly damaging pest, or a natural disaster could alter conditions dramatically enough that goals and recommendations are deemed irrelevant in their current form.

Plan Conclusion Regardless of the inherently slow nature of tree development and the vision required to appreciate progress, the urban forest viewed collectively is quite a dynamic and challenging resource to manage. Although it may take decades to fully understand and adjust to the broad patterns and trends influencing a tree population, every year existing trees are lost and new ones are establishing, which discernibly changes the composition of the forest. This plan is not only a guide to NMRWA’s Urban Forestry program, but also a comprehensive document to help inspire all stakeholders to appreciate and positively influence this essential watershed resource. While the watershed forest’s characteristics, environmental benefits, and tree canopy will change in ways foreseen and unforeseen, whether and how projects and initiatives compliment not only the daily lives of residents, but also the watershed ecosystem will be the most tangible measures of success over time.

52


APPENDIX Literature Cited 1. Olmsted, F.L. 1911. Pittsburgh Main Thoroughfares and The Down Town District: Improvements Necessary to Meet the City’s Present and Future Needs. Pittsburgh Civic Commission. 2. Davidson-Welling, John Paul & Molly. 1998. Brownfield Development: The Implications for Urban Infrastructure Case Study Site, Nine Mile Run. Carnegie Mellon University. 3. Collins, T.; Dzombak, D.; Rawlins, J.; Tamminga, K.; Thompson, S. 1998. Nine Mile Run Watershed Rivers Conservation Plan. Commonwealth of Pennsylvania Department of Conservation and Natural Resources. 4. City Policy Associates. 2008. Protecting and Developing the Urban Tree Canopy: a 135-City Survey. United Sates Conference of Mayors, Washington, DC. 5. Nine Mile Run Watershed Association. 2017. State of the Nine Mile Run Stream 2016 Report Card. 6. Nowak, D.J.; Stein, S.M.; Randler, P.B.; Greenfeld, E.J.; Comas, S.J.; Carr, M.A.; Alig, R.J. 2010. Sustaining America’s Urban Trees and Forests. USDA Forest Service, Northern Research Station. 7. Tree Pittsburgh. 2018. Allegheny County Tree Canopy Change 2010 to 2015. 8. Grove, J.M.; O’Neil-Dunne, J.; Kowalski, J. 2012. Urban Tree Canopy Assessment: Nine Mile Run Watershed. USDA Forest Service, Northern Research Station. 9. Elmendorf, W.F.; Cotrone, V.J.; Mullen, J.T. 2003. Trends in Urban Forestry Practices, Programs, and Sustainability: Contrasting a Pennsylvania, U.S., Study. Journal of Arboriculture 29(4). 10. Allegheny County Sanitary Authority. 2013. ALCOSAN Wet Weather Plan. 11. Davey Resource Group. 2013. Stormwater to Street Trees: Engineering Urban Forests for Stormwater Management. U.S. Environmental Protection Agency, Office of Wetlands, Oceans, and Watersheds, Nonpoint Source Control Branch. 12. Nowak D.J.; Stevens, J.C.; Sisinni, S.M.; Luley, C.J. 2002. Effects of Urban Tree Management and Species Selection on Atmospheric Carbon Dioxide. Journal of Arboriculture 28(3). 13. Karl, T.R.; Melillo, J.M.; Peterson, T.C. 2009. Global Climate Change Impacts in the United States. Cambridge University Press. 14. Akbari, H.; Taha, H. 1992. The Impact of Trees and White Surface on Residential Heating and Cooling Energy Use in Four Canadian Cities. Energy 17(2).

53


15. Dimke, K.C.; Sydnor, T.D.; Gardner, D.S. 2013. The Effect of Landscape Trees on Residential Property Values of Six Communities in Cincinnati, Ohio. Arboriculture & Urban Forestry 39(2). 16. Crompton, J.L. 2001. The Impact of Parks on Property Values: A Review of the Empirical Evidence. Journal of Leisure Research 33(1). 17. Hansmann, R.; Hug, S.; Seeland, K. 2007. Restoration and Stress Relief through Physical Activities in Forests and Parks. Urban Forestry & Urban Greening 6(4). 18. Donovan, G.H. 2017. Including Public-Health Benefits of Trees in Urban Forestry Decision Making. Urban Forestry & Urban Greening 22, 120-123. 19. Kim, J.; Kaplan, R. 2004. Physical and Psychological Factors in Sense of Community: New Urbanist Kentlands and Nearby Orchard Village. Environment & Behavior 36(3). 20. Kuo, F.E. 2003. The Role of Arboriculture in a Healthy Social Ecology. Journal of Arboriculture 29(3). 21. Nowak, D.J. 2013. Modeled PM 2.5 Removal by Trees in Ten US Cities and Associated Health Effects. Environmental Pollution 178. 395-402. 22. Coniff, R. 2014. Urban Nature: How to Foster Biodiversity in World’s Cities. Yale School of Forestry and Environmental Studies. 23. Clatterbuck, W.K.; Harper, C. 2012. Urban Trees for Wildlife. The University of Tennessee, Agricultural Extension Service. 24. Davey Resource Group. 2012. Pittsburgh Urban Forest Master Plan: A Road Map for the Effective Management of Our Urban Forest. Tree Pittsburgh. 25. Barringer, L. 2016. Pest Alert: Spotted Lanternfly. Pennsylvania Department of Agriculture. 26. Elmendorf, B. 2000. Seven Common Diseases of Landscape Trees. The Penn State University, College of Agricultural Sciences, Agricultural Research and Cooperative Extension. 27. Rejmanek, M.; Pitcairn, M.J. 2002. When is Eradication of Exotic Pest Plants a Realistic Goal? Turning the Tide: The Eradication of Invasive Species. Proceedings of the International Conference on Eradication of Island Invasives. 249-252. 28. Riley, C.B.; Herms, D. A.; Gardiner, M.M. 2017. Exotic Trees Contribute to Urban Forest Diversity and Ecosystem Services in Inner-City Cleveland, OH. Urban Forestry & Urban Greening. 29. Natural Resource Conservation Service. 2007. Pest Management - Invasive Plant Control: Japanese Knotweed. Conservation Practice Job Sheet MN-797. 30. Lenox, A.T. 2001. Invasive Weeds: Bush Honeysuckle. The Penn State University, College of Agricultural Sciences, Forest Resources Cooperative Extension. 31. United State Department of Agriculture. 2014. Field Guide for Managing Tree-of-Heaven in the Southwest. US Forest Service Southwestern Region. 32. Invasive Plants in Pennsylvania: Norway Maple. Pennsylvania Department of Conservation and Natural Resources. 33. Pittsburgh Parks Conservancy. Invasive Plants of Pittsburgh. 34. Union of Concerned Scientists. 2008. Climate Change Impacts and Solutions for Pennsylvania: How Today’s Actions Shape the State’s Future.

54


35. Kenney, W.A.; van Wassenaer, P.J.E.; Satel, A.L. 2011. Criteria and Indicators for Strategic Urban Forest Planning and Management. Arboriculture & Urban Forestry 37(3). 36. Roman, L.A.; Scatena, F.N. 2011. Street Tree Survival Rates: Meta-Analysis of Previous Studies and Application to a Field Survey in Philadelphia, PA, USA. Urban Forestry & Urban Greening 10, 269-274. 37. Watson, G.W.; Hewitt, A.M.; Custic, M.; Lo, M. 2014. The Management of Tree Root Systems in Urban and Suburban Settings II: A Review of Strategies to Mitigate Human Impacts. Arboriculture & Urban Forestry 40(5). 38. Arnold, M.A.; McDonald, G.V.; Bryan, D.L.; Denny, G.C.; Watson, W.T.; Lombardini, L. 2007. Below-Grade Planting Adversely Affects Survival and Growth of Tree Species from Five Different Families. Arboriculture & Urban Forestry 33(1). 39. Lohr, V.I.; Pearson-Mims, C.H.; Tarnai, J.; Dillman, D.A. 2004. How Urban Residents Rate and Rank the Benefits and Problems Associated with Trees in Cities. Journal of Arboriculture 30(1). 40. Raciti, S.; Galvin, M.F.; Grove, J.M.; O’Neil-Dunne, J.P.M.; Todd, A.; Clagett, S. 2015. Urban Tree Canopy Goal Setting: A Guide for Chesapeake Bay Communities. USDA Forest Service. 41. Jennings, V.; Baptiste, A.K.; Osborne Jelks, N.; Skeete, R. 2017. Urban Green Space and the Pursuit of Health Equity in Parts of the United States. International Journal of Environmental Research and Public Health 14, 1432. 42. Landry, S.M.; Chakraborty, J. 2009. Street Trees and Equity: Evaluating the Spatial Distribution of an urban amenity. Environment & Planning, 41, 2651-2670. 43. Scharenbroch, B.C.; Morgenroth, J.; Maule, B. 2016. Tree Species Suitability to Bioswales and Impact on the Urban Water Budget. Journal of Environmental Quality 45(1). 44. Raupp, M.J.; Buckelew Cumming, A.; Raupp, E.C. 2006. Street Tree Diversity in Eastern North American and its Potential for Tree Loss to Exotic Borers. Arboriculture & Urban Forestry 32(6). 45. Nowak, D.J.; Noble, M.H.; Sisinni, S.M.; Dwyer, J.F. 2001. People and Trees: Assessing the US Urban Forest Resource. Journal of Forestry 99(3). 46. Stevenson, T.R.; Gerhold, H.D.; Elmendorf, W.F. 2008. Attitudes of Municipal Officials toward Street Tree Programs in Pennsylvania, U.S. Arboriculture & Urban Forestry 34(3). 47. Penbrooke, T.L. 2017. Relevant Research for Practice 2017: Focus on Conservation and Resiliency. National Recreation and Park Association. 48. Walker, C. 2004. Beyond Recreation: The Public Value of Urban Parks. The Urban Institute. 49. TreePhilly. 2016. TreePhilly Progress Report 2012-2015. Philadelphia Parks & Recreation, Urban Forestry and Ecosystem Management Division. 50. Smiley, E.T. 2008. Comparison of Methods to Reduce Sidewalk Damage from Tree Roots. Arboriculture & Forestry 34(3). 51. Wolf, K.L. 2009. Strip Malls, City Trees, and Community Values. Arboriculture & Urban Forestry 35(1). 52. Bassuk, N. 2008. CU-Structural Soil: An Update after More than a Decade of Use in the Urban Environment. Cornell University, Urban Horticulture Institute.

55


We thank our key funders

Anonymous Supporter

The Laurel Foundation

CBB Foundation

The Rita M. McGinley Fund of The Pittsburgh Foundation

Questions? Comments? info@ninemilerun.org | 412-371-7889 ext. 116 | ninemilerun.org/our-work/urbanforestry 321 Pennwood Ave., #202 | Pittsburgh, PA 15221

10% post-consumer recycled content