Volume B covers the ecological significance of the interactions among clay minerals, organic matter and soil biota. Soil is a dynamic system in which soil minerals constantly interact with organic matter and microorganisms. Close association among abiotic and biotic entities governs several chemical and biogeochemical processes and affects bioavailability, speciation, toxicity, transformations and transport of xenobiotics and organics in soil environments. This book elaborates critical research and an integrated view on basic aspects of mineral weathering reactions; formation and surface reactivity of soil minerals with respect to nutrients and environmental pollutants; dynamics and transformation of metals, metalloids, and natural and anthropogenic organics; effects of soil colloids on microorganisms and immobilization and activity of enzymes, and metabolic processes, growth and ecology of microbes.