Red Oak Root and Soil Environmental Gradient Study, Midwest U.S., 2022-2023.

Fine root trait and soils data for Quercus rubra L. (northern red oak) sampled along a Midwestern latitudinal gradient. Fourteen sites spanning 5-14 degrees C were sampled. Each sample represents 2 6 cm deep x 5 cm wide soil cores obtained from near the base of a Q. rubra individuals, with 6 sampled plots per site. Plots were located approximately 40 m apart along a linear transect to be at a cluster of Q. rubra individuals. All 14 sites were visited twice in the growing season of 2022: between June 1st and June 21st, and between July 5th and July 21st.
Root traits sampled include average diameter, root tissue density, specific root length, branching intensity, and specific respiration rate. A 1 mm diameter limit cut-off was used. These traits were measured in the field (respiration rates) or from output from RhizoVision Explorer image analysis. Traits are associated with the smaller fine root sample used for respiration measurement in the field (~2 g dry weight). Fine root biomass was also obtained by removing all remaining fine roots in the core, drying, and weighing, and then was multiplied by weight-normalized respiration rates to obtain estimates of fine root ecosystem respiration.
This data package is complete, but will be associated with data from 4 sites revisited in 2023 to obtain repeat fine root trait measurements and fungal community community metrics.