Strategies to Manage the Loss of Ash and Elm Trees

This project brings together experts from different fields to identify ways to manage the decline of elm and ash trees across the eastern half of the United States. The goal is to provide guidance for land managers on how to deal with the widespread decline and loss of these trees. Strategies under consideration include identifying and potentially breeding elm and ash trees that are resistant to the pests, finding ways to control the pests, and figuring out how to restore and manage forests where ash and elm trees are dying or have died.

This project is testing different strategies and showing the results using forecast computer models and real-life projects. The research will help support our forests, improve environmental conditions, and promote fairness in how we take care of our natural resources.

Progress to Date

• In 2023, the research team asked for input from people who manage lowland forest types to make sure that the recommendations the team is developing are practical and useful.
• Several research projects related to lowland elm and ash decline and management are currently underway.
• The research team is gathering data from elm and ash field sites and tree inventories to understand how different management strategies affect these trees across different ecosystems.
• The team is working on forecasting computer models to predict the outcomes of different management strategies for elm and ash trees. This includes understanding the economic and social benefits of keeping or managing ash and elm trees.

Approach

• Efforts are underway to identify elm and ash trees that are resistant to pests and pathogens. Through various experiments and partnerships, the research team is testing trees to find the most resilient ones for planting and restoration. This includes studying genetic variability and conducting field trials to assess resistance.
• Biological control is being explored as a long-term solution to protect ash trees from emerald ash borer. The researchers are evaluating the effectiveness of parasitoid wasps in controlling emerald ash borer populations and monitoring their impact on ash trees' health.
• Research is ongoing to understand ash trees' resistance to emerald ash borer infestation. By studying the feeding preferences of emerald ash borer adults and the response of ash trees, the researchers are identifying resilient ash genotypes for future planting. Breeding programs are also being developed to enhance pest resistance.
• The research team is considering the impact of climate change on ash and elm trees and incorporating this into recommended management strategies. This includes studying how changing hydrological regimes affect tree performance and assessing the role of ash and elm trees in mitigating extreme weather events like heatwaves and heavy rainfall.
• The research is also looking at the implications of ash and elm tree loss on biodiversity and wildlife habitat. By studying insect populations and their relationships with other wildlife, the researchers aim to understand how managing these trees affects forest ecosystems and wildlife populations.

Outcomes

• This research will improve our understanding of elm and ash decline and promote management strategies to mitigate this decline.
• The team will continue to work with lowland forest managers to co-produce knowledge and solutions to elm and ash decline and make sure that managers are aware of new information and management solutions.
• Integrated pest management strategies are being evaluated to test the efficacy of larger-scale management of emerald ash borer.
• The team is working to produce calibrated decision support tools that will help municipal managers use a range of financial incentives to work with private and public landowners during crucial phases of infestation by emerald ash borer.
• The program is working in the short- and long-term to identify, breed, and test elm and ash trees that have demonstrated resistance in the wild, in order, hopefully, to achieve operational use of new resistant cultivars of both species.
• Habitat modeling and field physiological testing are expected to generate a palette of climate-adapted species that may be used at lowland forest sites disproportionately affected by the loss of elm and ash species.