Climate change may impact forest insects in a variety of ways that will likely put stress on the forest. Warmer temperatures, altered precipitation patterns, more frequent extreme weather events and longer growing seasons are a few consequences of climate change that may shape the effects of insects in future forests. A changing climate may impact insects as:

• Warmer temperatures accelerate larval development and increase insect populations.
• Extended growing seasons allow for more generations of insects each year.
• Altered leaf chemistry modifies insect host plant preferences.
• Extreme weather events damage and stress forests, resulting in attacks by native and non-native insects.
• Warmer temperatures allow insects to expand their range and occupy new areas.

Many examples of insects responding to climate change have already been documented. Two examples are:

1) Mountain pine beetle expanding its geographic range in the western U.S. and infesting a new host tree species during the most recent outbreak; and

2) Eastern larch beetle having an additional generation each year that has resulted in an unprecedented 20-year outbreak in Minnesota.

Wisconsin’s Statewide Forest Action Plan highlights some of the impacts insects may have on future forests, as well as potential solutions. The plan notes that forest pests may be more damaging in stressed forests, pest ranges may expand and the impacts of invasive species may increase. The plan has several suggestions to mitigate these impacts. The overarching goal is to manage forests so that they are more resilient and adaptable to climate change. However, forest management may be more difficult. Because of more frequent and severe weather events, management outcomes may be less predictable, opportunities to complete forest management may be limited and current management strategies may need to be adapted or changed.

Despite these challenges, the forest industry can enhance resilience and sustain ecological function by increasing species and genetic diversity, maintaining and expanding forest lands and keeping forests connected. It is critical that all forest landowners (private, tribal, state, county, federal) work together to achieve these goals. Working together to achieve healthy, resilient forests is critical to mitigating the impacts of climate change on Wisconsin’s forests and forest economy.