By Dr. Scott Abella, University of Nevada, Las Vegas
Presented on December 6, 2022
Abstract: The Oak Openings region in northwestern Ohio historically contained a mixture of woodlands and savannas dominated by oaks, mesic prairies, and riparian forest. Most of the fire-maintained oak woodlands and savannas were lost through the 1900s because of agricultural and urban development, lack of fire, and tree encroachment resulting in conversion to forest with overstory oaks and comparatively fire-intolerant trees in the understory, such as red maple. In this presentation, we provide an overview of ecological considerations influencing restoration and management in this region, followed by detailing results of restoration programs through managing abundant deer, reducing tree encroachment, and prescribed fires including delayed tree mortality. We discuss the ecological considerations of historical landscape composition based on early 1800s land surveys and presence of bison; 1900s land use history including agricultural clearing, establishment of conifer plantations, and persistence of old oaks based on dendroecological analyses; and the emerging issue of the fungal pathogen oak wilt. The deer management program corresponded with one of the most rapid increases in deer-sensitive plants yet reported and enabled a moderate deer population to coexist with a rising sensitive plant population. Restoration activities to reestablish open oak woodlands and savannas have succeeded since 1988 but have required frequent, persistent treatment applications to perpetuate a series of transient benefits over the last 20-30 years. The prescribed fire program and associated research has identified sizes of trees of different species able to be managed using fire while revealing that delayed mortality in red maple continued through at least four growing seasons after fire. This enabled prescribed fires to be more effective at reestablishing open oak woodland conditions than were suggested by short-term monitoring. We conclude the presentation by discussing anticipated future challenges to open-habitat conservation, such as a climatic shift to wetter early summers in this region.
