Environment Abstracts Annual 1991


Book Description




Ecology and Recovery of Eastern Old-Growth Forests


Book Description

The landscapes of North America, including eastern forests, have been shaped by humans for millennia, through fire, agriculture, hunting, and other means. But the arrival of Europeans on America’s eastern shores several centuries ago ushered in the rapid conversion of forests and woodlands to other land uses. By the twentieth century, it appeared that old-growth forests in the eastern United States were gone, replaced by cities, farms, transportation networks, and second-growth forests. Since that time, however, numerous remnants of eastern old growth have been discovered, meticulously mapped, and studied. Many of these ancient stands retain surprisingly robust complexity and vigor, and forest ecologists are eager to develop strategies for their restoration and for nurturing additional stands of old growth that will foster biological diversity, reduce impacts of climate change, and serve as benchmarks for how natural systems operate. Forest ecologists William Keeton and Andrew Barton bring together a volume that breaks new ground in our understanding of ecological systems and their importance for forest resilience in an age of rapid environmental change. This edited volume covers a broad geographic canvas, from eastern Canada and the Upper Great Lakes states to the deep South. It looks at a wide diversity of ecosystems, including spruce-fir, northern deciduous, southern Appalachian deciduous, southern swamp hardwoods, and longleaf pine. Chapters authored by leading old-growth experts examine topics of contemporary forest ecology including forest structure and dynamics, below-ground soil processes, biological diversity, differences between historical and modern forests, carbon and climate change mitigation, management of old growth, and more. This thoughtful treatise broadly communicates important new discoveries to scientists, land managers, and students and breathes fresh life into the hope for sensible, effective management of old-growth stands in eastern forests.




Biogeochemistry of Wetlands


Book Description

The globally important nature of wetland ecosystems has led to their increased protection and restoration as well as their use in engineered systems. Underpinning the beneficial functions of wetlands are a unique suite of physical, chemical, and biological processes that regulate elemental cycling in soils and the water column. This book provides an in-depth coverage of these wetland biogeochemical processes related to the cycling of macroelements including carbon, nitrogen, phosphorus, and sulfur, secondary and trace elements, and toxic organic compounds. In this synthesis, the authors combine more than 100 years of experience studying wetlands and biogeochemistry to look inside the black box of elemental transformations in wetland ecosystems. This new edition is updated throughout to include more topics and provide an integrated view of the coupled nature of biogeochemical cycles in wetland systems. The influence of the elemental cycles is discussed at a range of scales in the context of environmental change including climate, sea level rise, and water quality. Frequent examples of key methods and major case studies are also included to help the reader extend the basic theories for application in their own system. Some of the major topics discussed are: Flooded soil and sediment characteristics Aerobic-anaerobic interfaces Redox chemistry in flooded soil and sediment systems Anaerobic microbial metabolism Plant adaptations to reducing conditions Regulators of organic matter decomposition and accretion Major nutrient sources and sinks Greenhouse gas production and emission Elemental flux processes Remediation of contaminated soils and sediments Coupled C-N-P-S processes Consequences of environmental change in wetlands# The book provides the foundation for a basic understanding of key biogeochemical processes and its applications to solve real world problems. It is detailed, but also assists the reader with box inserts, artfully designed diagrams, and summary tables all supported by numerous current references. This book is an excellent resource for senior undergraduates and graduate students studying ecosystem biogeochemistry with a focus in wetlands and aquatic systems.




Southern Forest Science


Book Description

"Southern forests provide innumerable benefits. Forest scientists, managers, owners, and users have in common the desire to improve the condition of these forests and the ecosystems they support. A first step is to understand the contributions science has made and continues to make to the care and management of forests. This book represents a celebration of past accomplishments, summarizes the current state of knowledge, and creates a vision for the future of southern forestry research and management. Chapters are organized into seven sections: "Looking Back," "Productivity," "Forest Health," "Water and Soils," "Socioeconomic," "Biodiversity," and "Climate Change." Each section is preceded by a brief introductory chapter. Authors were encouraged to focus on the most important aspects of their topics; citations are included to guide readers to further information."




Riparian Areas


Book Description

The Clean Water Act (CWA) requires that wetlands be protected from degradation because of their important ecological functions including maintenance of high water quality and provision of fish and wildlife habitat. However, this protection generally does not encompass riparian areasâ€"the lands bordering rivers and lakesâ€"even though they often provide the same functions as wetlands. Growing recognition of the similarities in wetland and riparian area functioning and the differences in their legal protection led the NRC in 1999 to undertake a study of riparian areas, which has culminated in Riparian Areas: Functioning and Strategies for Management. The report is intended to heighten awareness of riparian areas commensurate with their ecological and societal values. The primary conclusion is that, because riparian areas perform a disproportionate number of biological and physical functions on a unit area basis, restoration of riparian functions along America's waterbodies should be a national goal.




Landscape Ecology in Theory and Practice


Book Description

An ideal text for students taking a course in landscape ecology. The book has been written by very well-known practitioners and pioneers in the new field of ecological analysis. Landscape ecology has emerged during the past two decades as a new and exciting level of ecological study. Environmental problems such as global climate change, land use change, habitat fragmentation and loss of biodiversity have required ecologists to expand their traditional spatial and temporal scales and the widespread availability of remote imagery, geographic information systems, and desk top computing has permitted the development of spatially explicit analyses. In this new text book this new field of landscape ecology is given the first fully integrated treatment suitable for the student. Throughout, the theoretical developments, modeling approaches and results, and empirical data are merged together, so as not to introduce barriers to the synthesis of the various approaches that constitute an effective ecological synthesis. The book also emphasizes selected topic areas in which landscape ecology has made the most contributions to our understanding of ecological processes, as well as identifying areas where its contributions have been limited. Each chapter features questions for discussion as well as recommended reading.




The Once and Future Forest


Book Description

Developed by the pioneering landscape design firm of Andropogon Associates, world-renowned for their innovative approach to integrating environmental protection and restoration with landscape architecture and design, The Once and Future Forest is a guidebook for restoring and managing natural landscapes. Focusing on remnant forest systems, it describes methods of restoring and linking forest fragments to recreate a whole landscape fabric. The book begins by explaining the history and current situation of forest ecosystems in the eastern United States. Following that is an in-depth examination of the restoration process, with thorough descriptions of ecological strategies for landscape management along with specific examples of how those strategies have been implemented in various sites around the country. The final section provides hands-on information about the many specific details that must be considered when initiating and implementing a restoration program. All aspects of the restoration process are considered, including: Water -- opportunities for increasing infiltration, reducing pollutants, promoting habitat values Ground -- methods of protecting existing vegetation, removing fill, rebuilding soils Plants -- strategies and procedures for planting, maintenance, propagation Wildlife -- guidelines for preserving wildlife resources, management techniques to favor selected specie. The Once and Future Forest presents a comprehensive approach to assessing sites, detailed guidelines for determining management goals, and a thorough overview of appropriate management and restoration techniques. It is an important guide for professional planners and landscape architects, government agency personnel at all levels, land managers, scientists involved in restoration work, and citizen activists who wish to do something constructive about our deteriorating forest patches.




Compensating for Wetland Losses Under the Clean Water Act


Book Description

Recognizing the importance of wetland protection, the Bush administration in 1988 endorsed the goal of "no net loss" of wetlands. Specifically, it directed that filling of wetlands should be avoided, and minimized when it cannot be avoided. When filling is permitted, compensatory mitigation must be undertaken; that is, wetlands must be restored, created, enhanced, and, in exceptional cases, preserved, to replace the permitted loss of wetland area and function, such as water quality improvement within the watershed. After more than a dozen years, the national commitment to "no net loss" of wetlands has been evaluated. This new book explores the adequacy of science and technology for replacing wetland function and the effectiveness of the federal program of compensatory mitigation in accomplishing the nation's goal of clean water. It examines the regulatory framework for permitting wetland filling and requiring mitigation, compares the mitigation institutions that are in use, and addresses the problems that agencies face in ensuring sustainability of mitigated wetlands over the long term. Gleaning lessons from the mixed results of mitigation efforts to date, the book offers 10 practical guidelines for establishing and monitoring mitigated wetlands. It also recommends that federal, state, and local agencies undertake specific institutional reforms. This book will be important to anyone seeking a comprehensive understanding of the "no net loss" issue: policy makers, regulators, environmental scientists, educators, and wetland advocates.




Learning Landscape Ecology


Book Description

Filled with numerous exercises this practical guide provides a real hands-on approach to learning the essential concepts and techniques of landscape ecology. The knowledge gained enables students to usefully address landscape- level ecological and management issues. A variety of approaches are presented, including: group discussion, thought problems, written exercises, and modelling. Each exercise is categorised as to whether it is for individual, small group, or whole class study.