The studies in the Ogawa Forest Reserve (OPR) were initiated by a group of plant ecologists and gradually expanded into a comprehensive project covering various aspects of biology, soil science, and silviculture. The project was integrated as part of the Forest Ecosystem Team under the BIO-COSMOS Program funded by the Ministry of Agriculture, Forestry and Fisheries. As the coordinators of the Forest Ecosystem Team, we are pleased that reports of the long-term studies carried out in the OFR are being published in this first volume on Japanese ecosystems in the Ecological Studies series. Scientists and researchers have made numerous contributions to the field of forest ecology during more than 10 years of studies in the OFR. Two reasons can be cited for the success of the project: scientists from various disciplines concen trated on a single target forest ecosystem, and the research continued over a rela tively long term. It is now recognized that ecological processes include compli cated mechanisms supported by interactions among organisms and large temporal variations. The researchers in the OFR project were motivated by their interest in the history of ecosystems and the interactions of diverse creatures in the forest.

Biodiversity is decreasing at the fastest rate in the history of the earth. The sustainable use of ecosystems allowing maintenance of biological diversity is an urgent problem that must be solved. The work featured in this book presents the results achieved by the RIHN project, together with reports on other international activities and related efforts, as ecologists, forestry scientists, environmental economists, and sociologists share in discussions of the issues.

Human colonization of New Zealand has dramatically altered the resident biota, introduced numerous alien organisms to these once remote islands, and exported local species to the world. This book reviews invasions, investigates what controls the success of invaders and studies the consequences for ecosystems both on land and offshore. The book tests current theories about the success of invaders and evaluates principles for effective management of biological invasions worldwide.

Coastal East and Southeast Asia are characterized by wet growing seasons, and species-rich forest ecosystems develop throughout the latitudinal and altitudinal gradients. In this region, the Global Change Impacts on Terrestrial Ecosystems in Monsoon Asia (TEMA) project was carried out as a unique contribution to the international project Global Change and Terrestrial Ecosystems. TEMA aimed to integrate forest ecosystem processes, from leaf physiology to meteorological budget and prediction of long-term change of vegetation composition and architecture through demographic processes. Special attention was given to watershed processes, where forest ecosystem metabolism affects the properties and biogeochemical budgets of freshwater ecosystems, and where rivers, wetlands, and lakes are subject to direct and indirect effects of environmental change. This volume presents the scaling-up concept for better understanding of ecosystem functioning.

Large-scale experimentation allows scientists to test the specific responses of ecosystems to changing environmental conditions. Researchers at Oak Ridge National Laboratory together with other Federal and University scientists conducted a large-scale climatic change experiment at the Walker Branch Watershed in Tennessee, a model upland hardwood forest in North America. This volume synthesizes mechanisms of forest ecosystem response to changing hydrologic budgets associated with climatic change drivers. The authors explain the implications of changes at both the plant and stand levels, and they extrapolate the data to ecosystem-level responses, such as changes in nutrient cycling, biodiversity and carbon sequestration. In analyzing data, they also discuss similarities and differences with other temperate deciduous forests. Source data for the experiment has been archived by the authors in the U.S. Department of Energy's Carbon Dioxide Information and Analysis Center (CDIAC) for future analysis and modeling by independent investigators.