Planting Trees in 2024

Forest management:
The mission of the Friends of the North Pikes Creek Wetlands organization includes the mandate to “Proactively implement informed scientific management activities to ensure the continuation of a healthy mosaic of habitats that support a diversity of wildlife.”

Today, the North Pikes Creek forests are faced with the multiple challenges of a warming climate and an imminent invasive pest infestation. The FNPCW organization is working proactively to address these challenges, and to help our forests remain healthy and continue to provide homes for wildlife.

Warming climate
Wisconsin will become warmer over the next few decades, with average temperatures similar to those historically characteristic of southern Iowa or Missouri. Since 1950, the average annual temperature in Wisconsin has warmed 3 degrees Fahrenheit, and it is projected that the state will warm an additional 4 to 8 degrees by 2050 (Wisconsin Initiative on Climate Change Impacts (WICCI)). Climate models agree that there will be increased drought stress due to increasing temperatures, increased duration between precipitation events, increased extreme weather events, such as heavy rains and flooding, and an increase in invasive insects.

The principal concerns facing our swamp hardwood forests will be the alteration of the soil hydrology in these wet sites, and damage from the emerald ash borer beetle. The climate conditions will no longer be conducive for the reproduction of current tree species – aspen, birch, and most lowland conifers – and the introduced emerald ash borer insect, which has expanded its range locally, will ultimately kill the black ash trees that are currently a dominant species in the swamp hardwood stands.

Helping trees move north
Forests have always migrated for their survival – their seeds are carried by the winds or moved by birds or squirrels. The average forest migrates at a rate of roughly 1,640 feet each year, but to outrun climate change, trees would need to move 10 times as fast. Without assistance, forests will be unable to move into a suitable climate by themselves.

The idea of assisted tree migration is not new. It was introduced in the scientific community 30 years ago. With today’s increased pace of warming, there is a need to quickly assist tree movement northward. Assisted migration is somewhat experimental. Trees grow slowly, so trees planted today should be those that will flourish in the conditions that will be here 50 years from now. The Friends are planting tree species – red oak, swamp white oak, bur oak, black cherry, hackberry, and disease resistant American elm – that are native to both southern Wisconsin, and further south.

Emerald ash borer Insect
The invasive emerald ash borer (EAB) was identified 2 years ago in the City of Bayfield, at a site just 4 miles from the Friends’ property, and the beetles are most likely at Beaver Hollow now. In response to this invasive pest, the Friends quickly launched their forest management plan. Tree species that are native to southern Wisconsin and are expected to thrive as climate conditions change, are being underplanted in the hardwood swamp stands. As EAB-infested ash trees begin to die back, the underplanted species will grow and fill in the voids. As the underplated trees mature they will take over the job of transpiration from the dying ash.

American elm trees once grew with black ash trees in low wet areas and along drainages in northern Wisconsin until Dutch elm disease virtually eliminated the species. It is interesting that we are now planting disease resistant elm trees in places where they once grew, to replace the black ash being destroyed by an invasive insect.