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Agroecosystem - those areas where at least 30% of the land is used for cropland or highly managed pastures

Aquaculture - cultivation of the natural produce of saltwater or freshwater-e.g., fin fish and shellfish

Boreal Forests - forests at high-latitudes and at lower latitudes in mountain ranges and high plateaus, found in two broad continental belts in North America and in Europe/Siberia

Brownfields - urban land areas that once supported industry or commerce but were abandoned and are presently unused and may be contaminated with industrial waste

Coastal Ecosystem - tidal areas above the continental shelf (to a depth of 200 meters) and adjacent land area up to 100 km inland

Conversion - modification of the basic physical properties — e.g., hydrology, soil structure, topography, vegetation — of an ecosystem

Coral Bleaching - the process whereby coral turns white as a result of losing the microscopic algae (zooxanthellae) that live in coral's tissues, loss caused by exposure to water temperatures 1-2 Celsius higher than the mean averages at the warmest time of year; global warming is one cause of higher temperatures

Desertification - the process of a non-desert ecosystem taking on the characteristics of a desert (arid, seemingly barren) as a result of land mismanagement or climate change

Ecological Footprint - the cumulative effect of degradative use of on an ecosystem

Ecosystem - a community of species that interact with each other and with the physical setting they live in

Endemic/Endemism - native to a particular region or ecosystem

Eutrophication - the process by which a body of water becomes rich in dissolved nutrients, such as phosphates and nitrates, that stimulate the growth of aquatic plant life, usually resulting in the depletion of dissolved oxygen in the water, causing fish to drown due to lack of oxygen

Forest Ecosystem - land areas dominated by trees where the tree canopy covers at least 10% of the ground area

Fragmentation - the dissecting of an ecosystem by the construction of roads, dams, and other infrastructure or by conversion whereby species habitats are split and avenues are opened for invasion by nonnative species and human settlement

Freshwater Ecosystems - inland surface water (e.g., rivers, lakes, and wetlands) and groundwater (e.g., underground springs and aquifers) systems

Fuelwood - wood grown specifically for or used as fuel

Grasslands Ecosystem - areas dominated by grassy vegetation and maintained by fire, grazing, and drought or freezing temperatures

Harmful Algal Blooms (HABs) - rapid increases in the populations of algae species that produce toxic compounds responsible for food poisoning, some of which are lethal to humans

Hypoxia - a condition caused when body tissues don't get sufficient oxygen to function; in aquatic ecosystems eutrophication may cause marine life to experience hypoxia and resulting disease or death

Infrastructure - the underlying foundation or basic framework of a built environment-e.g., sewage and plumbing systems

Invasive Species - nonnative plant and/or animal species introduced into a region that then overwhelm and crowd out native species, degrade habitats, and contaminate the gene pools of indigenous species

Periurban - surrounding or near a city; taking place at the city's edge

Persistent Organic Pollutants - any one of many synthetic compounds including polychlorinated byphenyls (PCBs), polychorinated dioxins and furans, pesticides such as DDT, chlordane, and heptachlor. They persist in the environment and accumulate through the food chain or in the sediment to a toxic level that is directly harmful to aquatic organisms and humans

Pollution - environmental contamination with man-made waste

Roundwood - all wood not used as fuel including all wood fiber products, from logs to pulp

Runoff - the renewable supply of water that flows through rivers after evaporation and infiltration

Telecommuting - working from home via an electronic linkup with a central office

Teleworking - working at a suburban satellite office via an electronic linkup with a central office

Urban Ecosystem - a biological community where humans represent the dominant or keystone species and the built environment is the dominant element controlling the physical structure of the ecosystem

Woodfuel - fuelwood, charcoal, and other wood-derived fuels

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