Wisconsin’s population of healthy oak trees is declining due to a variety of factors, including drought, invasive species and extreme weather, Wisconsin Public Radio reported Tuesday.
The DNR cited spongy moth infestations and the large number of storm-damaged branches on thousands of oaks, which makes them susceptible to deadly oak wilt — a fatal fungal disease that blocks a tree’s water-conducting system.
Spongy moths, which were at their invasive peak in Wisconsin from 2022-2024 but still pose a serious threat, are insects that chew through a tree’s leaves, making it more difficult for them to produce food and grow.
Tree declines and other kinds of forest degradation cause economic damage by reducing timber yields, destroying natural buffers against natural disasters and lowering property and tourism values.
