By many measures, Earths ecosystems are stressed. Actually, it may be more accurate to say that Earths remaining ecosystems are stressed. The fact is that most of the planets biomes support only a fraction of the biological communities they once did, primarily because humans have converted large areas of land to alternate uses. More than two-thirds of the global temperate forests, half of the grasslands, even a third of desert ecosystems have been conscripted for human uses like agriculture, construction, harvest and extraction. Cultivation alone covers a quarter of the habitable terrestrial surface. Aquatic ecosystems have not fared any better. An estimated half of the worlds wetlands are gone, particularly those of coastal regions or on arable land. About a fifth of the coral reefs and a third of the m- grove swamps of a century ago have been lost in just the last few decades. The volume of water impounded by dams quadrupled over the same period it now far exceeds the volume of water in unimpeded rivers (Millennium Ecosystem Assessment 2005; Mitsch and Gosselink 2007). So any assessment of ecosystem status is necessarily an analysis of fragments and remnants, and many of these are degraded by one or more anthropogenic stressors.

Preface.- Four Ecosystems, Four Questions; Oak Openings, Ohio; Kissimmee River, Florida; Tallgrass Prairie, Kansas; Six Rivers National Forest, California; Four Questions.- Part 1: Ecosystems in Theory.- The Ecosystem Idea and Ideal; Preservation, Conservation, and Ecology; Gleason and Individualism; Leopoldian Preservation and Conservation; Hutchinson, Holism, and Individualism; The New Ecology; Preservation of the Ideal; Toward an Ecosystem Approach to Management.- A Thing is Right; The Adaptive Cycle; Diversity, Stability, Health and Integrity.- Disturbance, Stress, and Resilience; Disturbance; Resilience; Complications of Stress.- Invasion; Colonization and Succession; Factors of Colonization; Nonnative Invaders; Passengers and Drivers; Ecosystem Function and Service; Ecosystem Service and Invasion; Eradication; A Conservation Dilemma.- Part 2: Ecosystems in Practice.- Very Small Ecosystems; Microbial Ecosystems; Biofilms as Model Ecosystems; Biofilms as Patches; Micro- and Macro-Ecosystems.- Forested Ecosystems; The Forest Sanctuary; The Monongahela Experiment; Wilderness Management; Healthy Forests; Unmanaged Forest Succession.- Grassland Ecosystems.- Grasslands, Short and Tall; Prairie Restoration and Umbrella Species; Land Trust Grasslands.- Freshwater Ecosystems; Wetlands; Lakes; Rivers.- Saltwater Ecosystems; Intertidal Ecosystems; Subtidal Ecosystems; Deeper Water.- Protecting the Shifting Quilt; Holism, Strong and Weak; The Four Horsemen Revisited; Along the Continuum; Protecting the Shifting Quilt.- Index.