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развивающий мультик для детей от 1 года про трактор, Urban Ecosystems: Balancing Nature in Cities - Green Living Answers, Effects of urban development on stream ecosystems in nine metropolitan , Urban ecosystem | Human Impact, Biodiversity & Pollution - Britannica, PBS - Bill Moyers Reports: Earth on Edge - Urban Ecosystems, Urban Forests: a valuable tool for building metropolitan green areas , Urban streams across the USA: Lessons learned from studies in 9 , Effects of Urban Development on Stream Ecosystems in Nine Metropolitan .
Urban development is an important agent of environmental change in the United States. The urban footprint on the American landscape has expanded during a century and a half of almost continuous development. Eighty percent of Americans now live in metropolitan areas, and the advantages and challenges of living in these developed areas—convenience, congestion, employment, pollution—are part of the day-to-day realities of most Americans. Nowhere are the environmental changes associated with urban development more evident than in urban streams. Contaminants, habitat destruction, and increasing streamflow flashiness resulting from urban development have been associated with the disruption of biological communities, particularly the loss of sensitive aquatic species. Every stream is connected downstream to larger water bodies, including rivers, reservoirs, and ultimately coastal waters. Inputs of chemical contaminants or sediments at any point along the stream can cause degradation downstream with adverse effects on biological communities and on economically valuable resources, such as fisheries and tourism.In response to general concerns about the degradation of urban streams, the U.S. Geological Survey (USGS) conducted a national-scale, scientific investigation of the effects of urban development on stream ecosystems. Nine metropolitan study areas of the United States were selected—Portland, Oregon; Salt Lake City, Utah; Birmingham, Alabama; Atlanta, Georgia; Raleigh, North Carolina; Boston, Massachusetts; Denver, Colorado; Dallas, Texas; and Milwaukee, Wisconsin. The studies were conducted in Salt Lake City, Birmingham, and Boston in 1999–2000; in Atlanta, Raleigh, and Denver in 2002–2003; and in Portland, Dallas, and Milwaukee in 2003–2004.The comprehensive investigation of all nine studies focused on three broad questions of interest to decision makers:, Urban ecosystems are the blend of nature and human-made structures that define our cities. They encompass everything from the air we breathe, the water that courses through our urban landscapes, to the greenery that dots our cityscapes., Eighty percent of Americans now live in metropolitan areas, and the advantages and challenges of living in these developed areas—convenience, congestion, employment, pollution—are part of the day-to-day realities of most Americans..
Urban ecosystem, any ecological system located within a city or other densely settled area or, in a broader sense, the greater ecological system that makes up an entire metropolitan area. The largest urban ecosystems are currently concentrated in Europe, India, Japan, eastern China, South America,, What goes on in cities affects all the ecosystems that surround them — the nearby forests, farms, and waterways. More than any other ecosystem, cities are permeable in their environmental effects., Urban Forests (UF) are a subset of Nature-Based Solutions that build on tree-based urban ecosystems to address societal challenges, simultaneously providing ecosystem services for human well-being and biodiversity benefits., We summarized the results from studies of the effects of urbanization on stream ecosystems in 9 metropolitan areas across the US (Boston, Massachusetts; Raleigh, North Carolina; Atlanta, Georgia; Birmingham, Alabama; Milwaukee-Green Bay, Wisconsin; Denver, Colorado; Dallas-Fort Worth, Texas; Salt Lake City, Utah; and Portland, Oregon)., In response to general concerns about the degradation of urban streams, the U.S. Geological Survey (USGS) conducted a national-scale, scientific investigation of the effects of urban development on stream ecosystems. Nine metropolitan study areas of the United States were selected—Portland, Oregon; Salt Lake City, Utah; Birmingham, Alabama , The concept recognizes that cities are not devoid of nature but are complex ecosystems at the intersection of the natural and constructed worlds. The Importance of Life in the City. The living organisms within a city provide environmental services that make urban areas more habitable. Vegetation improves air quality by absorbing pollutants and .