Street Tree Inventory Report Alameda Neighborhood September 2016 Street Tree Inventory Report: Alameda Neighborhood September 2016
Total Page：16
File Type：pdf, Size：1020Kb
Street Tree Inventory Report Alameda Neighborhood September 2016 Street Tree Inventory Report: Alameda Neighborhood September 2016 Written by: Kat Davidson, Angie DiSalvo, Julie Fukuda, Lily Glaeser, Jeremy Grotbo, and Jeff Ramsey Portland Parks & Recreation Urban Forestry 503-823-4484 [email protected] http://portlandoregon.gov/parks/treeinventory Alameda Tree Inventory Organizers: Tom Grier, Kurt Nordback, and Reed Ritchey Staff Neighborhood Coordinator: Lily Glaeser Data Collection Volunteers: Dennis Alexander, Bill Better, Ben Brady, Linda Brannan, Rick Burkard, Lauren Burns, Don Crossley, Casey Cunningham, JoAnna Dicarlo, Gregg Dicarlo, Brian Donnelly, Russell Eng, Dallen Esselstrom, Jon Feldhausen, Andrew Filipczak, David Gates, Tom Grier, Rob Hanifin, Karen Henell, Wendy Hoffman, Sabi Horvat, Frank Hostler, Diana Hsieh, Jake Jacobs, Kiel Jenkins, Bill Kownocki, Ariel Lewin, Linda Magnuson, Carlee Michelson, Louis Miles, Mark Miller, Melinda Moeur, Kristin Mohlman, Frances Moore, Charles Moore, Tim Moore, Jenny Moore, Roxy Nayar, John Nikkel, Kurt Nordback, Kevin Pozzi, Nathan Riggsby, Reed Ritchey, Judy Roumpf, Kyna Rubin, Paul Salvatore, Kathleen Scheinberg, Carl Schwab, Rita Schwenninger, Amy Simpson, Barry Skolout, Ann Smith, Arielle Solomon, Lizzie Sords, John Stephenson, Nancy Stephenson, Maurice Stewart, Loris Van Pelt, and Peter Vickery Data Entry Volunteers: Max Blasdel, Michael Brehm, Dylan Eglin, Kiel Jenkins, Spencer Keller, Bethany Lamb, Nathan Riggsby, Kristin Seller, Takayuki Shigematsu, Rebecca Tait, Shauna Volk, and Eric Watson Arborist-on-Call Volunteers: Van Bogner, Casey Clapp, Sean McMillen, Fred Nilsen, Damon Schrosk, and Doug Trotter GIS Technical Support: Josh Darling, Portland Parks & Recreation Financial Support: Portland Parks & Recreation Cover Photos (from top left to bottom right): 1) Attractive flowers on a chitalpa (x Chitalpa tashkentensis), an intergenetic hybrid. 2) The winged fruit of a Carolina silverbell (Halesia caroliniana). 3) A mature pecan tree (Carya illinoinensis), a rare find in Portland. 4) Colorful foliage and unusual sprays of flowers on a sourwood Oxydendron( arboreum). 5) The densely fuzzy leaves of a loquat (Eriobotrya japonica). 6) A closeup on the small flowers of a pagoda tree Sophora( japonica). 7) The raised lenticels and papery white bark of a Himalayan birch (Betula utilis var. jacquemontii). 8) Puffy clusters of fruit on a hophornbeam (Ostrya virginiana). ver. 10/13/2016 Portland Parks & Recreation 1120 SW Fifth Avenue, Suite 1302 Portland, Oregon 97204 (503) 823-PLAY Commissioner Amanda Fritz www.PortlandParks.org Director Mike Abbaté Contents Key Findings .......................................... 1 About Portland’s Street Tree Inventory . 3 Alameda Street Tree Inventory . 5 Neighborhood Characteristics ......................... 5 Urban Forest Composition............................ 5 Species diversity and tree type composition . 5 Functional tree type .............................. 7 Size class distribution ............................. 8 Mature tree form distribution ..................... 10 Importance value................................ 10 Tree Condition .................................... 11 Planting Site Composition and Stocking Level ........... 12 Planting sites................................... 13 Stocking level .................................. 14 Right tree in the right place ....................... 14 Replacement Value ................................. 15 Environmental and Aesthetic Benefits .................. 16 The Future Forest of Alameda ........................ 17 Recommendations ..................................... 21 Next Steps: Tree Plans and Tree Teams .................... 23 References ........................................... 25 Appendices........................................... 27 A: Methods ....................................... 27 B: Street trees of Alameda by tree type.................. 29 C: Street trees of Alameda by size (map) ................ 32 D: Vulnerability to key pests (map)..................... 33 E: Young street trees (trees ≤ 3” DBH) (map)............. 34 F: Large street trees (trees > 24” DBH) (map) ............ 35 G: Poor and dead street trees (map) .................... 36 H: Planting site types (map) .......................... 37 I: Planting site sizes (map)............................ 38 J: Available street tree planting sites (map) ............... 39 K: Priority street tree planting sites (map) ............... 40 Portland Parks & Recreation i Volunteers, guided by Portland Parks & Recreation Urban Forestry staff, collected data on all 3,501 street trees within Alameda 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 – Alameda Neighborhood 2016 Key Findings This report provides the results of a street tree inventory conducted in the Alameda neighborhood in 2016, along with Portland Parks & Recreation (PP&R) Urban Forestry staff recommendations for the Alameda tree team. Over the course of four work days, 65 volunteers contributed more than 320 hours collecting data on each of the neighborhood’s 3,501 street trees. URBAN FOREST STRUCTURE • Alameda’s street tree population is dominated by maple, cherry, dogwood, and plum and does not meet recommended species diversity guidelines. While 94 tree types were found in this inventory, two families, Rosaceae and Sapindaceae, account for more than 50% of the total street tree resource. Furthermore, both the Acer (maple) and Prunus (plum, cherry) genera are over represented as well, leaving Alameda’s street tree population vulnerable to pests, pathogens, and the effects of a changing climate. • The dominance of broadleaf deciduous trees (96%) in Alameda points to a need to plant more evergreen trees for year-round benefits and to create a more resilient, sustainable urban forest. • Only 16.3% of trees in Alameda 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. • Only 13.7% of Alameda’s street trees are large form varieties. Large form trees are necessary to increase canopy cover and the benefits they provide for Alameda’s residents. Planting the estimated 343 large available spaces identified in this inventory and replacing poor condition, undersized trees in large planting sites will maximize tree canopy in Alameda's rights-of-way. TREE CONDITION • The majority (92%) of trees inventoried in Alameda are in fair or good condition, however, more than half of the trees that are rated poor are in the Rosaceae. PLANTING SITES AND STOCKING LEVEL • Although 83% of street tree planting sites have trees in Alameda, there are 734 sites that are empty and ready for planting. • Less than one-quarter of Alameda’s large planting sites contain trees large enough for the site. Small form trees planted in large planting sites are a missed opportunity because larger trees contribute many times more benefits than do smaller ones. URBAN FOREST VALUE AND BENEFITS • Alameda’s street trees produce an estimated $704,751 annually in environmental and aesthetic benefits. The replacement value of this resource is $12.8 million. 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 top left: 1) Of the five Portland Heritage Trees in Alameda, only one is in the public right-of-way— this 60’ tall London planetree (Platanus x acerifolia), Heritage Tree #303. 2) These bambooleaf oaks (Quercus myrsinifolia), a broadleaf evergreen species that is a rare find in Portland, produce acorns for wildlife. 3) At 64.5” DBH, this silver maple (Acer saccharinum) is the largest diameter street tree in Alameda. 4) These young elms (Ulmus spp.) were planted a large strip with no overhead wires, which is an ideal location for large form trees like these. With continued care they will provide many benefits, such as shade and improved air quality, for many years. 2 Street Tree Inventory Report – Alameda Neighborhood 2016 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