Evidence for solum recarbonation following forest invasion of a grassland soil
Canadian Journal of Soil Science
Fuller, L. G., Wang, D. and Anderson, D. W. 1999. Evidence for solum recarbonation following forest invasion of a grassland soil. Can. J. Soil Sci. 79: 443–448. Calcareous organic-matter-rich Black Chernozemic soils often persist under poplar forests in Saskatchewan, not acquiring the Ae horizons and related properties more characteristic of Gray Luvisol soils. These are Rego Black Chernozems, locally termed “Wooded Calcareous” because of the occurrence of a dark, calcareous horizon (AC) at depths of 10 to 30 cm. We hypothesize that dark, calcareous horizons are former Bm horizons that have been recarbonated because of intense bio- cycling of Ca by aspen (Populus tremuloides). The comparatively small amounts of carbonate occur mainly in the fine silt and clay fractions, and are dominantly calcite, indicating secondary origin, in comparison to the carbonate minerals of the Ck horizons where both calcite and dolomite occur, the latter more common in coarse fractions. The δ13C values of the carbonate minerals indi- cate that virtually all the carbonate in fine fractions of the upper horizons of the Wooded Calcareous soil is pedogenic. The dom- inance of pedogenic carbonate in the Ahk and AC horizons of the Wooded Calcareous soil is consistent with a secondary enrichment, a probable result of increased biocycling of Ca where aspen grows on sites with large amounts of soluble Ca in the subsoil. High concentrations of soluble Ca2+ and SO 2– in the LFH of the Wooded Calcareous are consistent with increasing biocycling of these ions, from a gypsum-rich subsoil.
Fuller, L.G.; Wang, D.; and Anderson, D.W., "Evidence for solum recarbonation following forest invasion of a grassland soil" (1999). Aspen Bibliography. Paper 1095.