Long Term Response Of A Forest Watershed Ecosystem

A long-term study of the effects of clearcutting on forest and stream ecosystems.

Forests cover approximately 26% of the world's land surface area and represent a distinct biotic community. They interact with water and soil in a variety of ways, providing canopy surfaces which trap precipitation and allow evaporation back into the atmosphere, thus regulating how much water reaches the forest floor as through fall, as well as pull water from the soil for transpiration. The discipline "forest hydrology" has been developed throughout the 20th century. During that time human intervention in natural landscapes has increased, and land use and management practices have intensified. The book will be useful for graduate students, professionals, land managers, practitioners, and researchers with a good understanding of the basic principles of hydrology and hydrologic processes.

Of all the outputs of forests, water may be the most important. Streamflow from forests provides two-thirds of the nation's clean water supply. Removing forest cover accelerates the rate that precipitation becomes streamflow; therefore, in some areas, cutting trees causes a temporary increase in the volume of water flowing downstream. This effect has spurred political pressure to cut trees to increase water supply, especially in western states where population is rising. However, cutting trees for water gains is not sustainable: increases in flow rate and volume are typically short-lived, and the practice can ultimately degrade water quality and increase vulnerability to flooding. Forest hydrology, the study of how water flows through forests, can help illuminate the connections between forests and water, but it must advance if it is to deal with today's complexities, including climate change, wildfires, and changing patterns of development and ownership. This book identifies actions that scientists, forest and water managers, and citizens can take to help sustain water resources from forests.

With almost 90% of terrestrial plant material entering the detrital pool, the processing of this significant carbon source is a critical ecosystem function to understand. Riverine ecosystems are estimated to receive, process and transport nearly 1.9 Pg of terrestrial carbon per year globally, highlighting the focus many freshwater ecologists have on the factors that explain decomposition rates of senesced plant material. Since Webster and Benfield offered the first comprehensive review of these factors in 1986, there has been an explosion of research addressing key questions about the ecological interactions at play. Ecologists have developed field and laboratory techniques, as well as created global scale collaborations to disentangle the many drivers involved in the decomposition process. This book encapsulates these 30+ years of research, describing the state of knowledge on the ecology of plant litter decomposition in stream ecosystems in 22 chapters written by internationally renowned experts on the subject.

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.

The Fernow Watershed Acidification Study is a long-term, paired watershed acidification study. This book describes the responses to chronic N and S amendments by deciduous hardwood forests, one of the few studies to focus on hardwood forest ecosystems. Intensive monitoring of soil solution and stream chemistry, along with measurements of soil chemistry, and vegetation growth and chemistry, provide insights into the acidification process in forested watersheds.

The International Energy Agency Bioenergy Agreement was initiated as the Forestry Energy Agreement in 1978. It was expanded in 1986 to form the Bioenergy Agreement. Since that time the Agreement has thrived with some fifteen countries (Austria, Belgium, Canada, Denmark, Finland, Italy, Japan, Netherlands, New Zealand, Norway, Sweden, Switzerland, United Kingdom, United States and the CEC) currently being signatories. The objective of the Agreement is to establish increased programme and project cooperation between the participants in the field of bioenergy. The environmental consequences of intensive forest harvesting have been the subject of intense interest for the Agreement from its initiation. This interest was formulated as a Cooperative Project under the Forestry Energy Agreement in 1984. It developed further under each of the subsequent three-year Tasks of the Bioenergy Agreement (Task III, Activity 3 "Nutritional consequences of intensive forest harvesting on site productivity", Task VI, Activity 6 "Environmental impacts of harvesting" and more recently Task IX, Activity 4 "Environmental impacts of intensive harvesting". The work has been supported by five main countries from within the Bioenergy Agreement: Canada, New Zealand, Sweden, UK, and USA. The continued work has resulted in a significant network of scientists work ing together towards a common objective - that of generating a better under standing of the processes involved in nutrient cycling and the development of management regimes which will maintain or enhance long term site productivity.