Due to the paucity of long-term fire chronologies in the upper Midwest, we studied basal cross-sections dating back to 1822 and the impacts of recent fire suppression in pine and oak stands on the Menominee Indian Reservation in northeast Wisconsin. A total of 93 fire events with a fire-return interval (FRI) of 5.917.7 y were recorded across all stands before fire suppression activities in 1935. After 1935, we recorded 29 fires. Most stands have only burned 03 times since 1935, and only four of 16 stands yielded enough fire years to calculate FRIs. Superposed Epoch Analysis (SEA) determined significantly lower Palmer Drought Severity Index (PDSI) values 1 y before individual fire years. Fire wounding occurred primarily in the dormant season and average tree diameter at time of wounding ranged from 730 cm. Current forest composition was dominated by white pine (Pinus strobus L.) and red maple (Acer rubrum L.) overstories, whereas seedlings and saplings were predominantly eastern hemlock (Tsuga canadensis (L). Carrire), witch-hazel (Hamamelis virginiana L.) and sugar maple (A. saccharum Marsh.). Tree species recorded on similar soils in 19th Century General Land Office surveys were mainly aspen (Populus), white pine and eastern hemlock. We conclude that the combination of logging and decreased fire occurrence over the past century resulted in a compositional shift from historic aspen, pine and oak forests towards later successional northern hardwoods.
All Science Journal Classification (ASJC) codes
- Ecology, Evolution, Behavior and Systematics