MTGF Funding-

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We are requeted funds to accomplish this work through continued general support of the Urban Forestry Outreach & Research Lab as well as the University of Minnesota Elm Selection Program.

Rationale, Benefits to Grounds Managers

Continued development of high-quality instruction, research, and outreach programs to grounds managers, arborists, and school-age youth increases the value and investment in urban and community forests statewide. Additionally, research and workshop programming provided by University of Minnesota faculty and staff throughout Minnesota help to engage our communities and enhance the benefits of urban natural resources.

Objectives

1. University of Minnesota Urban Forestry Outreach & Research Programs (UFOR)

2. University of Minnesota Elm Selection Program (UMESP)

1. UMN Urban Forestry Outreach & Research Programs

2023 Objectives: 1) Continue the support of youth outreach, engagement, and recruitment programs in the metro as well as the exploration of programs that reach K12 kids in greater Minnesota. This includes development of skills and knowledge related to urban forestry and arboriculture, technical tree climbing, and methods of rope ccess used to safely enter and explore tree canopies. 2) Continue maintenance and enhancement of the Urban Forestry Outreach and Research Nursery & Lab on the UMN St. Paul Campus. This two-acre facility and lab space provides numerous opportunities for continuing education on tree related topics, research into gravel bed tree performance, and assessing how both new and long-established tree species are performing in Minnesota. 3) Refine methods for assessing tree vitality and health using SPAD meter technology. Quantification of a tree’s health and vitality is useful in determining if intervention is needed and if that intervention is effective. We will continue to expand on previous efforts to assess tree health using SPAD meters which quantify chlorophyll concentration in leaves non-destructively.

2023 Anticipated Outcomes

● Training events held on UMN Campus by UFOR Nursery & Lab (10-15 events)

● Youth Tree Climbing Events (4-7 events)

● A refined quantitative method for assessing tree health and vitality. Using this method we can better understand how site characteristics and Minnesota’s climate affects species performance - resulting in better recommendations for tree species placement and tree stress diagnostics.

Materials & Methods: Utilizing funds from MTGF and other sources, the UMN Urban Forestry Outreach and Research Lab will continue to serve hundreds of professionals and youth through in-person workshops, virtual content creation, school classroom visits, youth climbing experiences, and in-situ tree performance data acquisition.

2. University of Minnesota Elm Selection Program (UMESP)

Objectives: 1) Continue to identify putatively resistant elms in the Minnesota landscape, clonally propagate, and screen for DED resistance. 2) Study mechanisms of resistance by understanding pathogen movement in resistant trees. 3) Maintain elm research plots for long term resistance screening and for non-native resistant species.

Materials & Methods

As community engagement has increased and we have identified large survivor elms in the Minnesota landscape, we have a growing database of elm for potential scion material for clonal propagation. Collections and propagation will continue using traditional methods and developing enhanced propagation techniques. We also currently have a large collection of elms (over 100 selections) that were propagated from survivor elms in areas of heavy disease pressure from across the state and will continue to propagate them to numbers suitable for trials. Inoculations are conducted by injecting a known concentration of spores of a lab grown culture of the pathogen Ophiostoma novo-ulmi into the test tree via a small drill wound in the main stem. Ratings take place beginning four weeks post inoculation using a 11 point scale where 0=no wilt and 11=complete wilt and continue into the next growing season.

2023 Anticipated Outcomes

The project continues to yield successful results providing new information about Minnesota elms, their resistance to Dutch elm disease, and propagation techniques. In the coming growing season, we will evaluate 1-year inoculations of elm from a second set of commercially available DED resistant elm to study age affects. This consists of three commercially available DED resistant elms (Valley Forge, Jefferson, and Prairie Expedition) of which one set (10) was inoculated in 2020 to determine comparative resistance and to test inoculum dosage. The second set inoculated in the spring of 2022 will test if the two additional years of growth will affect resistance. Results from the inoculation in 2020 show limited wilt in the genotypes tested and similar wilt across all doses trialed.

Evaluations of a large replicated inoculation trial initiated in spring of 2022 will continue in 2023. This consisted of 15 new selections with 7 selections having six or more reps. Ratings from last growing season show 13 selections with a rating of 3 or lower (0=no wilt and 11=complete

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