Temporal and Spatial Soil Variability on Three Forested Landtypes on the Mid‐Cumberland Plateau

Abstract

AbstractTemporal and spatial variability of selected soil chemical properties were determined within and among three forested mid‐Cumberland Plateau landtypes at two locations. Major soils included Typic Fraguidults on uplands, Humic Hapludults on slopes, and Aquic Dystrochrepts in first‐order bottoms. Temporal soil variability was measured at monthly intervals for 25 consecutive months from samples taken from 0.5‐ by 0.5‐m subplots within two 2.5‐ by 2.5‐m plots on each landtype. Spatial variability samples were collected from similar, adjacent plots during a 1‐week period. A total of 300 spatial and 300 temporal observations were taken for each soil property in each of three soil horizons. Extractable Ca, Mg, and K, and pH in H2O and KCl were measured for A, AB, and Bt horizons, and total C was determined for A horizons. Magnitudes of variability were statistically compared using a procedure robust for nonnormally distributed data. Magnitudes of soil variability were significantly related to landtypes at the Bonferroni significance level. Only three of 16 soil variables differed in magnitudes of spatial vs. temporal variability. Variability on sites was of the order slopes > bottoms > uplands. Soil morphological features and parent materials appeared to strongly influence magnitudes of temporal and spatial variability.