Plants and Soil Clay Minerals

Abstract

A brief review of clay mineral assemblages in weathering profiles indicates that the upper-most zones (A horizons for the most part) contain species that are not present or less represented in the layers below, the alterite or C horizon. This is indicated in Chap. 3. If there is a difference in the A horizon mineralogy, it must be either due to a higher intensity of weathering due to rainwater and clay interaction, or to the influence of the chemistry engendered by plants on clay minerals. Since there is rarely an indication of more highly weathered minerals in the A horizon, such as gibbsite, one might suspect that the influence of plants can account for the differences in clay assemblages between A and C (alterite) horizons.