Street Tree Inventory Report Old Town-Chinatown Neighborhood November 2015 Street Tree Inventory Report: Old Town-Chinatown Neighborhood November 2015
Total Page：16
File Type：pdf, Size：1020Kb
Street Tree Inventory Report Old Town-Chinatown Neighborhood November 2015 Street Tree Inventory Report: Old Town-Chinatown Neighborhood November 2015 Written by: Kat Davidson, Nikhilesh Desai, Angie DiSalvo, Jeremy Grotbo, and Jeff Ramsey Portland Parks & Recreation Urban Forestry 503-823-4484 [email protected] http://portlandoregon.gov/parks/treeinventory Old Town-Chinatown Tree Inventory Organizer: Gloria Lee Staff Neighborhood Coordinator: Nikhilesh Desai Data Collection Volunteers: Dennis Alexander, Casey Cunningham, Timothy Desper, Gary Handy, Stephen Larson, Gloria Lee, Betty Jean Lee, Trevor Manning, Alicia Peteck, Jeff Renfro, Stephanie Renfro, Evelyn Roeloffs, Mary Kay Ruskusky, Kym Setzer, Peggy Thompson, Gary Thompson, Merlin Varaday, Annie Willis, and Helen Ying Data Entry Volunteers: Ben Brady, Carl Burdick, Max Carlstrom, Megan Cohen-Doyle, and Eileen Meinel Arborist-on-Call Volunteer: Ron Davies GIS Technical Support: Josh Darling, Portland Parks & Recreation Financial Support: Portland Parks & Recreation Cover Photos (from top left to bottom right): 1) The linear leaves and tiny acorns of a Quercus myrsinifolia. 2) Profusely blooming cherry trees frame the Steel Bridge. 3) An unusual viburnum tree (Viburnum awabuki) near Lan Su Chinese Garden. 4) A guardian statue at the Chinatown Gate. 5) Palms (Trachycarpus spp.) in Old Town-Chinatown. 6) The foliage of a dawn redwood (Metasequoia glyptostroboides). 7) A woman sits in the shade of this Heritage Tree, a Yoshino cherry (Prunus x yedoensis). 8) Fruit ripening on a saucer magnolia tree (Magnolia x soulangeana). ver. 10/15/2015 Portland Parks & Recreation 1120 SW Fifth Avenue, Suite 1302 Portland, Oregon 97204 (503) 823-PLAY Commissioner Amanda Fritz www.PortlandParks.org Director Mike Abbaté Table of Contents Key Findings .......................................... 1 About Portland’s Street Tree Inventory . 3 Old Town-Chinatown Street Tree Inventory ................ 5 Neighborhood Characteristics ......................... 5 Urban Forest Composition............................ 6 Species diversity and tree type composition . 6 Functional tree type .............................. 8 Size class distribution ............................. 9 Mature tree form distribution ..................... 10 Importance value................................ 10 Tree Condition .................................... 11 Planting Site Composition and Stocking Level ........... 12 Planting sites................................... 13 Stocking level .................................. 13 Right tree in the right place ....................... 14 Replacement Value ................................. 15 Environmental and Aesthetic Benefits .................. 16 The Future Forest of Old Town-Chinatown ............. 17 Recommendations ..................................... 21 Next Steps: Tree Plans and Tree Teams .................... 23 References ........................................... 25 Appendices........................................... 27 A: Methods ....................................... 27 B: Street trees of Old Town-Chinatown by tree type....... 29 C: Street trees of Old Town-Chinatown by size (map) ..... 30 D: Vulnerability to key pests (map)..................... 31 E: Young street trees (trees ≤ 3” DBH) (map)............. 32 F: Large street trees (trees > 24” DBH) (map) ............ 33 G: Poor and dead street trees (map) .................... 34 H: Planting site types (map) .......................... 35 I: Planting site sizes (map)............................ 36 J: Available street tree planting sites (map) ............... 37 K: Priority street tree planting sites (map) ............... 38 Portland Parks & Recreation i Volunteers, guided by Portland Parks & Recreation Urban Forestry staff, collected data on all 1,002 street trees within Old Town-Chinatown neighborhood to compile the neighborhood’s first complete street tree inventory. The data are being used to inform the creation of a Neighborhood Tree Plan to guide volunteers in caring for their community’s trees. ii Street Tree Inventory Report – Old Town-Chinatown Neighborhood 2015 Key Findings This report provides the results of a street tree inventory conducted in the Old Town-Chinatown neighborhood in 2015, along with Portland Parks & Recreation (PP&R) Urban Forestry staff recommendations for the Old Town-Chinatown tree team. Over the course of one work day, 20 volunteers contributed more than 80 hours collecting data on each of the neighborhood’s 1,002 street trees. URBAN FOREST STRUCTURE • The street tree population lacks diversity at all levels in Old Town-Chinatown. Over half of all street trees are maples, and the Acer (maple) genus is five times greater than the recommended diversity guideline. Lack of species diversity makes the neighborhood’s street tree population vulnerable to pests, pathogens, and effects of a changing climate. • The dominance of broadleaf deciduous trees (94%) points to a need to plant more evergreen trees for year-round benefits and to help create a more resilient, sustainable urban forest. • Only 4% of trees in Old Town - Chinatown are young (<3” DBH), leaving few trees to offset mortality as the population ages. Frequent planting of young trees helps to ensure a stable street tree population with a healthier age distribution in the future. • Two-thirds of trees are on their way to maturity and are sized between 6” and 18” DBH. These trees have survived the establishment period and should be monitored and maintained to ensure they reach maturity and to reduce future maintenance costs. • Only 9% of Old Town-Chinatown’s street trees are large form varieties. Large form trees are necessary to increase canopy cover and the benefits they provide for Old Town-Chinatown’s residents. Replacing dead and poor condition, undersized trees in large planting sites with large form trees will ensure that maximum benefits are provided as the canopy develops. TREE CONDITION • Most trees (92%) are in fair or good condition. Of the 8% of trees that rated poor, half are maples. Only 1% of trees are dead. PLANTING SITES AND STOCKING LEVEL • Eighty-six percent of planting sites have trees in Old Town-Chinatown and 167 sites are available for planting. Choosing the appropriate tree for the site will ensure maximum benefits as the canopy develops. • Increasing current canopy levels will require planting trees outside of the existing right-of-way spaces. Available right-of-way sites may not be enough to equitably distribute canopy in Old Town- Chinatown. Creative expansion of planting sites or increased planting in parks, private property and parking lots may be the only ways to increase canopy much above the current level of 10%. URBAN FOREST VALUE AND BENEFITS • Old Town-Chinatown’s street trees produce an estimated $128,913 annually in environmental and aesthetic benefits. The replacement value of this resource is $3,288,158. Planting efforts focused on appropriately sized trees distributed across the neighborhood will ensure that future benefits are equitably distributed among all residents. Portland Parks & Recreation 1 Clockwise from left: 1) Lan Su, a Ming Dynasty-style garden, occupies an entire city block in the Chinatown District, offering a peaceful escape from the bustle of the city. 2)The median on West Burnside offers a large planting space in Old Town-Chinatown. Photographed here is a newer planting of the silverbell or snowdrop tree (Halesia carolina), amidst well established maples. 3) With a DBH of 36”, this cherry tree (Prunus spp.) is the largest diameter street tree in the neighborhood. 4) Mature Norway maples line the transit mall in Old Town-Chinatown. 2 Street Tree Inventory Report – Old Town-Chinatown Neighborhood 2015 About Portland’s Street Tree Inventory THE IMPORTANCE OF STREET TREES Street trees are an important public asset in urban environments, serving as a buffer between our transportation corridors and our homes while enhancing the livability of our city. As integral components of a community’s green infrastructure, street trees provide multiple economic, environmental, and social benefits such as cleaner air and water, cooler summer temperatures, safer streets, and increased property values. Unlike traditional, “grey” infrastructure, which begins to deteriorate the moment it is installed, the benefits that street trees provide increase over the lifetime of the tree, making their planting and maintenance one of the best investments a city and its residents can make. While street trees are only one component of Portland’s urban forest, they are particularly important because they are the trees that residents Urban forests are complex, living interact with most. Having adequate information resources that interact both about the street tree population allows a community to make informed decisions about species selection, positively and negatively with the planting, and maintenance priorities. Information on surrounding environment. They the location, condition, and diversity of the street tree produce multiple benefits and have population enables our communities to steward this resource and ensure its continued benefits into the associated management costs. In order future. Undertaking a street tree inventory is not only to fully realize the benefits, a sound an investment in the current and future well-being of the trees, but in the community itself. understanding of the urban forest THE INVENTORY PROCESS resource is needed. This understanding Portland’s Tree Inventory Project