04/20/23 1

A Tale of Four CitiesA Tale of Four CitiesExotic and Invasive Pest Analysis

and Issue CharacterizationPresented by:

Davey Resource GroupDeborah Sheeler

Project Partners

This project was made possible by:

U.S. Department of Agriculture Forest Service

Illinois Department of Natural Resources

City of Evanston

Village of Skokie

Village of Wilmette

Village of Winnetka

What’s Happening?

Our urban forests are threatened by exotic and invasive insects and diseases.

How can we best manage?

Where to Start?

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?Public Tree Inventories

Management Plans

Urban Tree Canopy Analysis

Tree OrdinancesHyperspectral Imagery

i-Tree Streets Benefits Model

Funding

In 2009, Illinois Department of Natural Resources was awarded a grant from the Northeastern Area State and Private Forestry Council to analyze:

Effectiveness and practicality of using various management tools and strategies to control exotic pest threats to public and private forests.

Project Goals

Assist communities to better understand what management tools are available for assessing the threat of exotic and invasive pests to their community forests

Demonstrate the advantages and limitations of select management tools, and the deliverables and costs associated with these tools

A Tale of Four CitiesA Tale of Four Cities

The urban forests in the Chicago, Illinois area are under intense pressure from exotic invasive insects and diseases. The four communities of Evanston, Skokie, Wilmette, and Winnetka have all implemented various management strategies to battle these exotic pests.

This is their tale…..

Background of Four CitiesBackground of Four Cities

The four communities of Evanston, Skokie, Wilmette, and Winnetka are all designated as a Tree City USA by the National Arbor Day Foundation

The project area is 27 square miles with city populations ranging from 12,000 to 74,000

All communities had existing tree ordinances and management plans

With the exception of Winnetka, all had a current inventory of public street trees

None of the four communities were utilizing hyperspectral imagery, i-Tree Streets Benefit Model, or Urban Tree Canopy Analysis

Exotic Invasive Insects and Diseases Evaluated

Emerald Ash Borer – EAB(Agrilus planipennis)

Dutch Elm Disease – DED (Ophiostoma novo-ulmi)

Oak Wilt (Ceratocystis fagacearum)

Tools and Management Strategies Analyzed

Tree Ordinances - SummaryIn A Tale of Four Cities, the ordinances of Evanston, Skokie, Wilmette, and Winnetka are examples of how this legal tool can be used effectively to manage invasive insects and diseases within municipal boundaries.

Advantages:Provide the legal framework within which local tree management activities are conducted for the general welfare and for specific issuesExpand the municipality’s ability to take legal and appropriate action on privately owned trees

Limitations:Must be formally adopted by the municipalityAre not effective if not enforced properlyCan be too species specific Need to be updated and reviewed periodically

Management Plans – SummaryThe communities of Evanston, Skokie, Wilmette, and Winnetka all rely on management plans or strategies to guide them in reducing the negative impacts of invasive insects and diseases.Advantages:

Establish goals and make management recommendations for tree care activitiesCreate unique approaches, like cost-share programs to incentivize

proactive management on the part of property ownersProvide action plans, budgets, and timelines for implementation of management strategiesProvide protocols and set standards for managing exotic invasive pests

Limitations:Can become outdated if not reviewed and updatedGoals of community may change and new threats may develop

Public Tree Inventories – SummaryEvanston, Skokie, and Wilmette have conducted complete tree inventories. The Village of Winnetka does not have a current tree inventory so a 6% random i-Tree Streets inventory was conducted. Inventories are valuable tools for managing threats to a community.Advantages:

The costs of performing and maintaining inventories have proven to be a worthwhile investment in relation to the benefits

Data collection that includes location, species, condition, size, and recommended maintenance information can be used to accurately report the effect of exotic invasive pests

Data can be used for short- and long-term budgeting and planningA GIS-based inventory will better demonstrate the spatial placement of the community’s

treesLimitations:

It is vitally important to maintain and update the tree inventory on a regular basis or the investment loses value in the long term

i-Tree Streets Benefit Model - Summary In A Tale of Four Cities, i-Tree Streets was a cost-benefit analysis tool used to quantify the environmental services that the entire street tree population provides as well as what the susceptible species of oak, elm, and ash street trees contribute. Advantages:

The highest benefit of i-Tree is using the results to communicate the benefits of trees and the need for increased proactive management

i-Tree results can be utilized to develop effective public relation and educational campaignsi-Tree is a defensible methodology that can show there is a positive benefit-cost ratio for

managing this municipal assetLimitations:

Tree inventory data must be available and it requires technical expertise to execute the analysis and fully use all of the capabilities of the program

i-Tree provides benefits for species that comprise over 1 percent of the total street tree population. Reports for all species that exist may not be available.

Hyperspectral Imagery - SummaryFor A Tale of Four Cities, HSI was used to depict the location and concentrations of green and white ash, American elm, and northern red oak tree canopy that are at risk to invasive insects and diseases.Advantages:

Hyperspectral Imagery as a separate tool is beneficial in visually depicting and mapping the canopy of targeted tree species

Community foresters can utilize HSI maps for effective communication for the need for proactively managing the potential threats from invasive insects and diseases to avoid loss of tree canopy to a community’s urban forest

HSI identifies both private and public trees and gives a complete picture of the community forestLimitations:

The cost may be prohibitiveA HSI project is only a “snapshot” of conditions at the time of the project

Hyperspectral Imagery - Results

Predicted Loss of Canopy Due to Invasive Insects and Diseases

Species Evanston Skokie Wilmette Winnetka

green and white ash 35.1 34.4 28.0 31.4

American elm 15.3 8.6 8.8 8.7

northern red oak 12.9 11.7 8.2 9.3

Total Canopy (acres) 63.3 54.7 45.0 49.4

Hyperspectral imagery (HSI) is a relatively new remote-sensing technology that can be used to map the canopy of both public and private trees at the species level.

Urban Tree Canopy Analysis - SummaryMunicipalities can use Urban Tree Canopy (UTC) data to better plan for potential planting projects and to further assist their public relation campaigns in response to invasive threats.Advantages:

The results of a UTC can be used to establish baseline conditions, benchmark against similar communities, set goals for improvement, and create plans for planting and protecting trees

UTC mapping is GIS-compatible and can be used by the community and stakeholders for many other uses

Limitations:A UTC is not species-specific and does not determine the percentage of canopy threatened

by invasive insects and diseases UTCs are best used in combination with other GIS data and imagery

Urban Tree Canopy Analysis - ResultsTotal Acres of Tree Canopy

Evanston Skokie Wilmette Winnetka

1,842.8 (36.9%)

1,850.1 (28.8%)

1,510.2 (43.6%)

1,306.5 (52.7%)

Urban Tree Canopy (UTC) analysis utilizes remote-sensing and GIS technologies to determine the cover of leaves, stems, and branches of trees.

Conclusions

Comparison of Management Tools

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Ordinances $ X X X X 3 Management Plans $ X X X 2 Tree Inventories $ - $$$$ X X X X 1 i-Tree Streets Benefit Model $ X X X X X 1 Hyperspectral Imaging $$$$ X X X X X X 5 Urban Tree Canopy

Analysis $ - $$$ X X X X X X 3

1 The cost is most often associated with project size and detail. This pricing is based on current, average industry costs; $ = <$5,000; $$ = $5,000-$15,000; $$$ = $15,000-$25,000; $$$$ = >$25,000.

Community OutreachOutreach and education to citizens, elected officials, businesses, and other community stakeholders is a key factor in successfully managing exotic and invasive pests. The ability to map the threat and demonstrate the value of the urban forest is an integral part of an educational program.

Management ToolsThis project did not evaluate all available urban forestry management tools that can be used to manage exotic and invasive pests. Each community should research these tools as well when preparing a response to these threats.

A Tale of Four CitiesEvanston, Skokie, Wilmette, and Winnetka all have chosen similar urban forestry management tools – some simple and some advanced – to help understand and manage the threat of exotic and invasive pests. With the results of this study, these communities can now compare the effectiveness of these tools, share management strategies and better understand the threats to their urban forest, and create a multi-faced response that best serves the needs and conditions of the community and forest.

What’s NextThe goal of this project is to assist other communities to better understand what tools are available for assessing the threat of exotic pests. The next step is to promote and share the results of this project.

For More Information

Illinois Department of Natural Resourceswww.dnr.illinois.gov

U.S. Forest Service, Department of Agriculturewww. fs.fed.us

USFS i-Treewww.itreetools.org

Contact Josh Behounek (josh.behounek@davey.com)www.davey.com