The material presented here is based on presentations and discussions held at the 1990 Sigtuna workshop. We have organized the material into five sections, the first containing papers of general relevance to all the developed research plans, followed by three sections divided by geographical regions (high-latitude, mid-latitude, and tropical ecosystem regions), and the final section dealing with rice paddy agriculture, which because of its potential role as a significant source of CH4 and N2O was singled out for a specific set of studies. Each section, except the first dealing with general issues, concludes with a working group report developed at the workshop. These reports identify specific research needs to address biosphere atmosphere exchange research for each region.

Suserup Skov in Denmark is a well-preserved beech-dominated forest reserve with continuity in tree cover at least back to 4200 BC, indicating it to be a direct descendent of the primeval forests. Despite of documented historical impact from humans, Suserup Skov is now increasingly characterized by natural disturbance dynamics and is one of the best reference areas for naturalness in the nemoral part of northern Europe. This has attracted several research projects focussing on forest dynamics, ecology and biodiversity which are summarized in this issue of Ecological Bulletins. This volume focuses on three main areas: 1) stand structures and dynamics 2) water and nutrient cycling processes, and 3) vegetation patterns and processes. With a compilation of scientific reviews, detailed case-studies and experimental works, the volume provides a unique and in-depth overview of structures and processes in a single forest reserve. The aim is to establish a basic reference of science and practice within forestry and nature conservation.

How can we understand and rise to the environmental challenges of global change? One clear answer is to understand the science of global change, not solely in terms of the processes that control changes in climate and the composition of the atmosphere, but in how ecosystems and human society interact with these changes. In the last two decades of the twentieth century, a number of such research efforts--supported by computer and satellite technology--have been launched. Yet many opportunities for integration remain unexploited, and many fundamental questions remain about the earth's capacity to support a growing human population. This volume encourages a renewed commitment to understanding global change and sets a direction for research in the decade ahead. Through case studies the book explores what can be learned from the lessons of the past 20 years and what are the outstanding scientific questions. Highlights include: Research imperatives and strategies for investigators in the areas of atmospheric chemistry, climate, ecosystem studies, and human dimensions of global change. The context of climate change, including lessons to be gleaned from paleoclimatology. Human responses to--and forcing of--projected global change. This book offers a comprehensive overview of global change research to date and provides a framework for answering urgent questions.

Carbon and Nitrogen in the Terrestrial Environment is a comprehensive, interdisciplinary description of C and N fluxes between the atmosphere and the terrestrial biosphere; issues related to C and N management in different ecosystems and their implications for the environment and global climate change; and the approaches to mitigate emission of greenhouse gases. Drawing upon the most up-to-date books, journals, bulletins, reports, symposia proceedings and internet sources documenting interrelationships between different aspects of C and N cycling in the terrestrial environment, Carbon and Nitrogen in the Terrestrial Environment fills the gap left by most of the currently available books on C and N cycling. They either deal with a single element of an ecosystem, or are related to one or a few selected aspects like soil organic matter (SOM) and agricultural or forest management, emission of greenhouse gases, global climate change or modeling of SOM dynamics.