Data in this dataset were collected from an experiment studying the long-term consequences of fire and thinning to reverse mesophication in midwestern oak savannas. Beginning in 2010, experimental management has occurred on a fire-suppressed oak savanna at MSU MacCready Reserve in Jackson County, MI. This property has been divided into fifteen management units, and randomly assigned one of three treatments (Burn Only, Thin-Burn, and Unmanaged). This repeated management (with repeated prescribed fire every 2-3 years in Burn Only and Thin-Burn units, and three rounds of thinning in the Thin-Burn units) has created structural differences between these management approaches (See Bassett et al., 2020). The data in this dataset were collected from all 15 of these management units across 7 rounds every 2-4 weeks during the 2025 growing season (May through September). To evaluate how these management regimes influence key measures of mesophication, including microclimate, canopy structure, and leaf litter attributes, we repeatedly measured these attributes from samples taken in the field and measures taken in both the field at laboratory, using the methods outlined in the manuscript. Rows represent the treatment rounds for each plot (nested within unit) sampled from within the management treatment unit (the experimental unit of replication). Columns represent the measures taken, including canopy openness, leaf litter temperature, air temperature, humidity, wind speed, and the moisture content and composition of the litter (oak) calculated in the lab.

0.5 × 0.5 m sampling plots were spaced 10 m apart in a 10 × 30 m grid within each management unit (n=5). Sampling occurred between 10 am and 4 pm from May 15th through September 29th, 2025. Canopy openness was measured using a handheld spherical densiometer, centered above the plot. PAR was measured 1.5 m above the plot using an Apogee Quantum Flux PAR meter model MQ-301. Air temperature, relative humidity, and wind speed were measured using a Kestrel 3000 pocket weather meter held 1.5 m above the center of each plot. Litter temperature was measured using a handheld infrared thermometer at the approximate center of each plot. Leaf litter depth was measured at each corner of the plot and averaged for analysis. Leaf litter was collected and dried in the lab (at 65°C for 48–72 hours) to assess moisture content, then sorted by oak (Quercus) and non-oak species. Soil moisture was measured at the center of each plot using an HH2 Moisture Meter probe inserted to a depth of 5.7 cm. For more details on Sampling methods and approach, see section 2.3 of the associated manuscript.