This volume contains reviewed papers from BIOGEOMON, The Fourth International Symposium on Ecosystem Behavior, held at the University of Reading in August 2002, and attended by over 260 participants from 25 countries. The papers in this volume focus on themes that have always been strong at BIOGEOMON, such as: Beyond these traditionally emphasized themes, other papers focus on: Audience: This book will be of interest to researchers in biogeochemistry, ecosystem ecology, global change, and anthropogenic pollution, as well as to natural resource managers and policy specialists.