Download or read book Dynamic Approaches to Modeling Wetland Community Responses to Changing Water Availability written by Courtney Davis and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Of the myriad of issues facing amphibian populations worldwide, the direct and indirect effects of climate change are among the most difficult to isolate and predict. The effects of climate change on distributions of individual species do not occur in isolation but instead are the outcome of interactions between climate, co-occurring species, and the physical environment in which interactions occur. However, current models do not consider community dynamics or complex interactions between climate and the physical environment, making it difficult to predict how community assemblages will be affected. For wetland communities, in particular, shifts in regional climate are likely to have profound and ongoing effects on site suitability and as a result, species composition. We examined how patterns of amphibian occurrence responded to extreme climate events at St. Marks National Wildlife Refuge from 2009 -- 2014, where fluctuations in precipitation have resulted in periods of extreme drought as well as expansive flooding. High rainfall associated with Tropical Storm Debby in 2012 allowed for the colonization of predatory fishes to many previously isolated wetlands. Using long-term monitoring data, we parameterized a set of dynamic multispecies occupancy models that incorporate habitat dynamics and species interactions to investigate the occurrence dynamics of three representative amphibian species in response to changing water availability (Chapter 1). Additionally, we investigate how an adaptation to variable environmental conditions -- facultative paedomorphism, as exhibited in one of these three species -- further structures responses to these disturbance events (Chapter 2). Drought and predatory fishes had differing effects on amphibian occurrence dynamics for each of the three species we examined. The occupancy of ornate chorus frogs (Pseudacris ornata), a species that preferentially selects ephemeral wetlands to breed, increased from 30% to 50% of surveyed wetlands during periods of drought in 2010 -- 2011. Mole salamander (Ambystoma talpoideum) occupancy, however, decreased from 40% to 25% due to the reduction of wetland hydroperiod at this time. For both of these species, fishes negatively impacted occurrence; wetlands occupied by fish were rarely, if ever, colonized by either the ornate chorus frog or the mole salamander. Despite the ability to modify its phenotype in favorable environmental conditions, the mole salamander occupied less than 20% of wetlands by 2014, suggesting that conditions remained unfavorable for this species, in particular. Pig frog (Rana grylio) occupancy, however, was not influenced by changes in climate during the study or changes in fish presence on the refuge. Projecting community composition under various climate scenarios (i.e., future increases in drought and/or flood frequency), we further demonstrate that responses to changing water availability are linked to species traits, characteristics of individual wetlands, and the interaction between climate and the physical environment.

Download or read book Wetland Ecosystems written by William J. Mitsch and published by John Wiley & Sons. This book was released on 2009-04-13 with total page 309 pages. Available in PDF, EPUB and Kindle. Book excerpt: New focused text introduces readers to wetland ecosystems and systems approaches to studying wetlands With its comprehensive coverage of wetland science, management, and restoration, Mitsch and Gosselink's Wetlands has been the premier reference on wetlands for more than two decades. Now, the coverage of specific wetland ecosystem types from earlier editions of this acclaimed work has been updated, revised, and supplemented with additional content in order to create this new text focusing exclusively on wetland ecosystems. This book now complements Wetlands, Fourth Edition. Following an introduction to ecosystems in general and wetland ecosystems in particular, Wetland Ecosystems examines the major types of wetlands found throughout the world: coastal wetlands, freshwater marshes and forested swamps, and peatlands. The final chapter reviews three fundamental systems approaches to studying wetlands: mesocosms, full-scale experimental ecosystems, and mathematical modeling. This new text features: Updated descriptions of the hydrology, biogeochemistry, and biology of the main types of wetlands found in the world New content introducing general ecosystems, wetland ecosystems, whole ecosystem and mesocosm experiments with wetlands, and systems ecology and modeling A detailed description of the ecosystem services provided by wetlands A broad international scope, including many examples of wetlands located outside North America Two new coauthors offering new perspectives and additional insights into the latest ecosystem and modeling techniques An abundance of illustrations helps readers understand how different biological communities and the abiotic environment in wetland ecosystems interact and function. Tables and text boxes provide at-a-glance summaries of key information. Lastly, each chapter concludes with a list of recommended readings. This text has been designed as an introduction for students and professionals in wetland ecology and management, general ecology, environmental science, and natural resource management.

Download or read book Wetland Modelling written by W.J. Mitsch and published by Elsevier. This book was released on 2012-12-02 with total page 238 pages. Available in PDF, EPUB and Kindle. Book excerpt: The study of wetlands is a relatively new field and the modelling of these systems is still in its formative stages. Nevertheless, the editors felt compelled to assemble this volume as a first statement of the state of the art of modelling approaches for the quantitative study of wetlands. A global approach has been adopted in this book, not only by including a wide geographic distribution of wetlands, but also by including papers on both freshwater and saltwater wetlands. Wetlands are defined as systems intermediate between aquatic and terrestrial ecosystems, and include ecosystems under a wide range of hydrologic and ecologic conditions. The wetland types discussed in this book reflect that heterogeneity, ranging from intermittently flooded wet meadows to permanently flooded shallow reservoirs and lakes. Also included are modelling examples from coastal salt marshes, shallow estuaries, mesotrophic bogs, reedswamps, forested swamps, and regional wetlands. In summary, the book presents ecological modelling as a tool for management of these sensitive ecosystems, and for studying their structure and function. Each chapter has extensive references related to the modelling approach and wetland type discussed. It will be useful for wetland scientists and managers, and could also serve as a supplemental text on courses in wetland ecology.

Download or read book The Application of Remote Sensing and GIS for Improving Modeling the Response of Wetland Vegetation Communities to Water Level Fluctuations at Long Point Ontario written by Jingwen Huang and published by . This book was released on 2016 with total page 89 pages. Available in PDF, EPUB and Kindle. Book excerpt: Coastal wetlands are complex and dynamic environments which are of high environmental, social, and economic importance. With the acceleration of climate change and global warming, it is necessary to monitor and protect dynamic coastal wetlands. Wetland ecosystem simulation modeling is one approach to help produce better wetland protection and management strategies. The application of remote sensing and Geographic Information System (GIS) in wetland ecosystem simulation models can help with better spatial modeling of wetland ecosystems. In addition, coastal topographic models can achieve digital representations of terrain surfaces and aquatic environments. This study applies remote sensing and GIS technologies for improving wetland vegetation simulation modeling. First, the study integrates multiple topographic data sources (i.e. Light Detection and Ranging data (LiDAR) and bathymetry data) to generate a coastal topographic model. Shoreline data are involved in the generation process. Second, a pre-existing wetland simulation model is updated to a new version to model the response of wetland vegetation communities to water level fluctuations at Long Point, Ontario. Third, different coastal topographic models have been employed to explore how a coastal topographic model affects the wetland simulation results. Model sensitivity analysis is conducted to explore the variation of model simulation results to different vegetation transition baselines parameter. Findings from this study suggest that a high accuracy coastal topographic model could yield a higher accuracy simulation result in a wetland ecosystem simulation model. Second, the application of remote sensing and the integration of multiple topographic data (e.g. LiDAR data and bathymetry data) could provide high accuracy and high density elevation information in coastal area, especially in land-water transitional areas. Finally, a narrower vegetation transition baseline increases the possibility for a wetland community shift to a wetter wetland community.

Download or read book Reconstructing the Past and Modeling the Future of Wetland Dynamics Under Climate Change written by Meghan Halabisky and published by . This book was released on 2017 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract Reconstructing the past and modeling the future of wetland dynamics under climate change Meghan Halabisky Chair of Supervisory Committee: Dr. L. Monika Moskal School of Environmental and Forest Sciences Wetland ecosystems are widely considered to be highly sensitive to climate change. However, scientific capacity to model climate impacts to wetlands has been hampered by the lack of accurate maps showing the spatial distribution of wetlands and data on their historical hydrological dynamics. Though these data may exist for particular wetlands, there are no broad scale datasets of wetland location and long-term hydrological dynamics. Remote sensing has been an important vehicle for mapping change to wetlands, but generally at spatial or temporal scales that do not capture the variability necessary for linking climate to wetland hydrodynamics. This data limitation and lack of methods have restricted research on how changes in climate will impact wetland hydrology to explorations of limited scope. The goal of this PhD was to characterize and model historic and future climate impacts to dynamics of wetland hydrology (i.e. inundation quantity, frequency, timing and duration) across the Columbia Plateau ecoregion. To achieve this goal, I developed new remote sensing methods to map and reconstruct wetland dynamics for thousands of individual wetlands at finer temporal and spatial resolutions than previously available (Chapter 1 and 2). In Chapter 1, I combined high-resolution aerial photographic imagery and a time series of Landsat satellite imagery to reconstruct wetland inundation patterns for individual wetlands from 1984 – 2011 in Douglas County, WA, USA. A key component of this method was the ability to measure fine scale changes (

Download or read book Modelling the Impact of Climate Change on Water Resources written by C. Fai Fung and published by John Wiley & Sons. This book was released on 2011-07-05 with total page 215 pages. Available in PDF, EPUB and Kindle. Book excerpt: The quantitative assessment of the impact of climate change on water availability and water resources management requires knowledge of climate, hydro(geo)logical and water resources models, and particularly the relationships between each of them. This book brings together world experts on each of these aspects, distilling each complex topic into concise and easy to understand chapters, in which both the uses and limitations of modelling are explored. The book concludes with a set of case studies using real-life examples to illustrate the steps required and the problems that can be faced in assessing the potential impacts of climate change on water resource systems. For students, scientists, engineers and decision-makers alike, this book provides an invaluable and critical look at the information that is provided by climate models, and the ways it is used in modelling water systems. A key focus is the exploration of how uncertainties may accrue at each stage of an impacts assessment, and the reliability of the resulting information. The book is a practical guide to understanding the opportunities and pitfalls in the quantitative assessment of climate change impacts and adaptation in the water resource sector.

Download or read book Addressing Climate Change in Long term Water Resources Planning and Management written by Levi D. Brekke and published by DIANE Publishing. This book was released on 2011 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: Describes the water management community¿s needs for climate change info. and tools to support long-term planning. Technical specialists and program managers have worked with their planners, water operators, and environmental compliance managers to identify the information and tools most relevant to their programs. They also have engaged and consulted with other Federal, State, and local agencies and stakeholder groups that have a role in water and water-related resource management to identify complementary priorities and individual perspectives. This report will help focus research and technology efforts to address info. and tools gaps relevant to the water management user community. Charts and tables. This is a print on demand report.

Download or read book Impact of Water Level Changes on Woody Riparian and Wetland Communities written by U.S. Fish and Wildlife Service and published by . This book was released on 1977 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wetland and Water Resource Modeling and Assessment written by Wei Ji and published by CRC Press. This book was released on 2007-12-13 with total page 328 pages. Available in PDF, EPUB and Kindle. Book excerpt: As a wetland of international importance located in China, the Poyang Lake Basin's incredible topographical and biological diversity has provided a congregating point for scientists from around the world to engage in cross-disciplinary research. In particular, the International Conference on Poyang Lake Complex Environment System was instrumental i

Download or read book Wetlands written by William J. Mitsch and published by John Wiley & Sons. This book was released on 2011-08-24 with total page 675 pages. Available in PDF, EPUB and Kindle. Book excerpt: Praise for the previous editions of Wetlands: "Wetlands, the field of study, would not be what it is without Wetlands, the book." ——Bill Streever, Wetlands, 2001 "The Third Edition of this highly successful book manages to set new standards in presentation and content to confirm its place as the first point of reference for those working or studying wetlands." ——Chris Bradley, University of Birmingham, UK, Regulated Rivers: Research and Management "This book is the wetlands bible...the most wide-ranging [book] on the subject." ——Carl Folke, Royal Swedish Academy of Sciences, Land Use Policy "The single best combination text and reference book on wetland ecology." ——Joseph S. Larson, University of Massachusetts, Journal of Environmental Quality "First on my list of references to recommend to someone new to wetland policy management or science." ——Jay A. Leitch, North Dakota State University, Water Resources Bulletin For more than two decades, William Mitsch and James Gosselink's Wetlands has been the premier reference on wetlands for ecologists, land use planners, and water resource managers worldwide—a comprehensive compendium of the state of knowledge in wetland science, management, and restoration. Now Mitsch and Gosselink bring their classic book up to date with substantial new information and a streamlined text supplemented with a support web site. This new Fourth Edition maintains the authoritative quality of its predecessors while offering such revisions as: Refocused coverage on the three main parts of the book: 1. An introduction to the extent, definitions, and general features of wetlands of the world; 2. Wetland science; and 3. Wetland management. New chapter on climate change and wetlands that introduces the student to the roles that wetlands have in climate change and impact that climate change has on wetlands. Increased international coverage, including wetlands of Mexico and Central America, the Congolian Swamp and Sine Saloum Delta of Africa, the Western Siberian Lowlands, the Mesopotamian Marshland restoration in Iraq, and the wetland parks of Asia such as Xixi National Wetland Park in eastern China and Gandau Nature Park in Taipei, Taiwan. This expanded coverage is illustrated with over 50 wetland photographs from around the world. Several hundred new refer?ences for further reading, up-to-date data, and the latest research findings. Over 35 new info boxes and sidebars provide essential background information to concepts being presented and case studies of wetland restoration and treatment in practice.

Download or read book Vulnerability of Coastal Wetlands in the Southeastern United States written by Glenn R. Guntenspergen and published by . This book was released on 1998 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Selected Water Resources Abstracts written by and published by . This book was released on 1990 with total page 1180 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Ecosystem Response Modelling in the Murray Darling Basin written by Neil Saintilan and published by CSIRO PUBLISHING. This book was released on 2010 with total page 449 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ecosystem Response Modelling in the Murray-Darling Basin provides an overview of the status of science in support of water management in Australia's largest and most economically important river catchment, and brings together the leading ecologists working in the rivers and wetlands of the Basin. It introduces the issues in ecosystem response modelling and how this area of science can support environmental watering decisions. The declining ecological condition of the internationally significant wetlands of the Murray-Darling Basin has been a prominent issue in Australia for many years. Several high profile government programs have sought to restore the flow conditions required to sustain healthy wetlands, and this book documents the scientific effort that is underpinning this task. In the Southern Murray-Darling Basin, the River Murray, the Murrumbidgee River and their associated wetlands and floodplains have been the focus of the Murray-Darling Basin Authority's 'The Living Murray' program, and the NSW Rivers Environmental Restoration Program. The book documents research aimed at informing environmental water use in a number of iconic wetlands including those along the Murray - the Barmah-Millewa Forest; the Chowilla Floodplain and Lindsay-Wallpolla Islands; the Coorong and Murray mouth; and the Murrumbidgee - the Lowbidgee Floodplain. Within the Northern Murray-Darling Basin, research conducted in support of the Wetland Recovery Plan and the NSW Rivers Environmental Restoration Program has improved our knowledge of the Gwydir Wetlands and the Macquarie Marshes, and the water regimes required to sustain their ecology.

Download or read book Wetlands and Water Resources Ecological Solutions for the Environment written by Guangzhi Sun and published by Frontiers Media SA. This book was released on 2023-04-12 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wetlands are usually located in complex landscapes. Multiple ecosystem services delivered by wetlands to human well-being should be considered in broader contexts of wetland functions, water quality, water resource management and wetland conservation. Natural wetlands are 'kidneys' and 'sponges' of the earth that remove water pollutants and provide hydrological regulation functions vital to the environment. Where the functions of the wetlands are weakened, actions of rehabilitations are needed to revitalize those functions. While worldwide many natural wetlands have disappeared due to climate change and/or human activities, constructed wetlands, which may be seen as 'artificial kidneys/sponges' of the earth, have been increasingly built to replicate the functions of the natural wetlands. This Research Topic aims to collect and present the latest research developments in natural and constructed wetlands in relation to either water resource functions or water quality. Articles published in this Research Topic will showcase new understandings of water balances and flow patterns, vegetation characteristics, and pollutant transformations in wetland systems; innovative designs and efficiencies of wastewater treatment wetlands; and technologies that revitalize the ecosystem functions of natural wetlands. These articles are expected to bring benefits to research communities, water and wastewater industries, and government agencies that deal with wetland water management and conservation. High-quality Original Research and Review articles in this field are all welcome for submission to this Research Topic. Research interests include but are not limited to the following areas: 1. Water balances and flow patterns in natural wetland systems. 2. The hydrological regulation functions and importance of natural wetlands in their environmental context. 3. Vegetation characteristics of natural wetlands and their functional importance in wetland water pollution control. 4. Techniques for the rehabilitation of degraded wetlands. 5. The role of constructed wetlands in wastewater treatment. 6. Innovative designs and efficiencies of wastewater treatment wetlands. 7. The modeling of hydrological and/or pollutant dynamics in wetland systems. 8. The ecohydrology of wetlands. 9. The role of wetlands in the global carbon cycle. 10. Impacts of climate change and human activities on wetland hydrology and water resources. Recognizing that hydrological and biogeochemical processes are basically coupled in wetlands and their landscapes, manuscripts that report their interactions are particularly welcome.

Download or read book The Study of Seasonal Composition and Dynamics of Wetland Ecosystems and Wintering Bird Habitat at Poyang Lake PR China Using Object based Image Analysis and Field Observations written by Iryna Dronova and published by . This book was released on 2012 with total page 278 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wetlands are among the most productive ecosystems in the world which support critical ecological services and high biological diversity yet are vulnerable to climate change and human activities. Despite their tremendous economic and ecological value, substantial uncertainty still exists about wetland ecosystem function, habitats and response to natural and anthropogenic stressors worldwide. This uncertainty is further aggravated by constrained field access and surface heterogeneity which limit the accuracy of wetland analyses from remote sensing images. In this thesis, I investigated the capabilities of satellite remote sensing with medium spatial resolution and object-based image analysis (OBIA) methods to elucidate seasonal composition and dynamics of wetland ecosystems and indicators of habitat for wintering waterbirds in a large conservation hotspot of Poyang Lake, PR China. I first examined changes in major wetland cover types during the low water period when Poyang Lake provides habitat to large numbers of migratory birds from the East Asian pathway. I used OBIA to map and analyze the transitions among water, vegetation, mudflat and sand classes from four 32-m Beijing-1 microsatellite images between late fall 2007 and early spring 2008. This analysis revealed that, while transitions among wetland classes were strongly associated with precipitation and flood-driven hydrological variation, the overall dynamics were a more complex interplay of vegetation phenology, disturbance and post-flood exposure. Remote sensing signals of environmental processes were more effectively captured by changes in fuzzy memberships to each class per location than by changes in spatial extents of the best-matching classes alone. The highest uncertainty in the image analysis corresponded to transitional wetland states at the end of the major flood recession in November and to heterogeneous mudflat areas at the land-water interface during the whole study period. Results suggest seasonally exposed mudflat features as important targets for future research due to heterogeneity and uncertainty of their composition, variable spatial distribution and sensitivity to hydrological dynamics. I further explored the potential of OBIA to overcome the limitations of the traditional pixel-based image classification methods in characterizing Poyang Lake plant functional types (PFTs) from the medium-resolution Landsat satellite data. I assessed the sensitivity in PFT classification accuracy to image object scale, machine-learning classification method and hierarchical level of vegetation classes determined from ecological functional traits of the locally dominant plant species. Both the overall and class-specific accuracy values were higher at coarser object scales compared to near-pixel levels, regardless of the machine-learning algorithm, with the overall accuracy exceeding 85-90%. However, more narrowly defined PFT classes differed in their highest-accuracy object scale values due to their unique patch structure, ecology of the dominant species and disturbance agents. To improve classification agreement between different levels of vegetation type hierarchy and reduce the uncertainty, future analyses should integrate spectral and geometric properties of vegetation patches with species' functional ecological traits. In periodically flooded wetlands such as Poyang Lake, rapid short-term surface dynamics and frequent inundation may constrain detection of directional long-term effects of climate change, succession or alien species invasions. To address this challenge, I proposed to classify Poyang Lake wetlands into "dynamic cover types" (DCTs) representing short-term ecological regimes shaped by phenology, disturbance and inundation, instead of static classes. I defined and mapped Poyang Lake DCTs for one flood cycle (late summer 2007-late spring 2008) from combined time series of medium-resolution multi-spectral and radar imagery. I further assessed sensitivity of DCTs to hydrological and climatic variation by comparing results with a hypothetical change scenario of a warmer wetter spring simulated by substituting spring 2008 input images with 2007 ones. This analysis identified the major steps in seasonal wetland change driven by flooding and vegetation phenology and spatial differences in change schedules across the heterogeneous study area. Comparison of DCTs from the actual flood season with the hypothetical scenario revealed both directional class shifts away from expanding permanent water and more complex location-specific redistributions of vegetation types and mudflats. These outcomes imply that changes in flooding may have non-uniform effects on different ecosystems and habitats and call for a thorough investigation of the future change scenarios for this landscape. The possibility to disentangle short-term ecological "regimes" from longer-term landscape changes via DCT framework suggests a promising research strategy for landscape ecosystem modeling, conservation and ecosystem management. Following the assessments of Poyang Lake dynamics in the low water season, I further examined which landscape characteristics of the permanent sub-lakes and their 500-m neighborhoods extracted from 30-m Landsat satellite imagery could explain non-uniform spatial distribution of waterbird diversity and abundance in the ground bird survey of December 2006. I hypothesized that the indicators of habitat size, spectral greenness, spectral and geometric patch heterogeneity would be positively associated with bird diversity and abundance, while the proportions of cover types approximating human disturbance would be negatively related to response variables. In the best-fit regression models selected using the Akaike Information Criterion, on average higher bird diversity and abundance were associated with larger sub-lake size, higher spectral greenness of emergent grassland and lower spectral greenness of mudflat as well as lower proportion of flooded/aquatic vegetation. At the same time, predictive performance of the best-fit models was penalized by large amounts of unexplained variation and inconsistencies among bird survey and remote sensing data from another year. Significant spatial autocorrelation in linear regression models raised concerns about missing predictor variables and the utility of sub-lakes as spatial units for diversity analysis, but it also suggested new hypotheses on spatial ecological interactions in bird community variables and habitat characteristics among sub-lakes. Research challenges identified in this study suggest that future monitoring programs should take more rigorous steps to standardize the protocols of bird surveys and improve spatial and temporal frequency of both bird and habitat observations. Rapid short-term surface variation and problematic field access will likely continue to limit remote sensing-based analyses of Poyang Lake wetlands and their habitats by traditional, static-class approaches. Using "dynamic" classes representing characteristic wetland transitions and disturbance regimes may provide more ecologically informative targets for management, conservation and modeling of ecosystem change. Object-based image analysis is a potentially powerful and promising approach to enhance classification accuracy of remote sensing data and ecologically informative interpretations of complex, heterogeneous wetland surfaces such as the study area. However, this methodology should be developed further to allow for more automated optimization of landscape object properties to capture vegetation patch structure and quantitatively assess propagation of the uncertainty among different spatial scales of the analysis. Finally, future studies should explore new ways of overcoming the limitations of problematic field access and frequent cloudiness obstructing the view of remote sensors by more rigorous utilization of in situ wireless sensors to record environmental conditions and surface composition and by introducing airborne lake-wide imaging programs for periods of prolonged cloudiness.

Download or read book Northern Prairie Wetlands written by Arnoud van der Valk and published by Wiley-Blackwell. This book was released on 1989 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt: The northern prairie region includes the prairie pothole region and the Nebraska sandhills. The first chapter deals with the social and economic conditions in the prairie pothole region and their impacts on the perception that farmers, business executive, and politicians in the region have of its wetland. The next three chapters deal with hydrology and water chemistry. They describe the physical and chemical environment of northern prairie wetlands. The flora and fauna are covered in seven chapters. An overview of the ecology of the wetlands of the Nebraska sandhills is provided in the last chapter.

Download or read book Global Environmental Change written by National Research Council and published by National Academies Press. This book was released on 1999-09-14 with total page 621 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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 effortsâ€"supported by computer and satellite technologyâ€"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 toâ€"and forcing ofâ€"projected global change. This book offers a comprehensive overview of global change research to date and provides a framework for answering urgent questions.