The ecosystem of a river is the river viewed as a system operating in its natural environment, and includes biotic (living) interactions amongst plants, animals and micro-organisms, as well as abiotic (nonliving) physical and chemical interactions.
River ecosystems are prime examples of lotic ecosystems. Lotic refers to flowing water, from the Latin lotus, washed. Lotic waters range from springs only a few centimeters wide to major rivers kilometers in width. Much of this article applies to lotic ecosystems in general, including related lotic systems such as streams and springs. Lotic ecosystems can be contrasted with lentic ecosystems, which involve relatively still terrestrial waters such as lakes and ponds. Together, these two fields form the more general study area of freshwater or aquatic ecology.
The following unifying characteristics make the ecology of running waters unique from that of other aquatic habitats.
Bohemian Switzerland (Czech: České Švýcarsko; German: Böhmische Schweiz), also known as Czech Switzerland, is a picturesque region in the north-western Czech Republic. It lies on the Czech side of the Elbe Sandstone Mountains north of Děčín on both sides of the Elbe River. It extends eastward into the Lusatian Mountains and westward into the Ore Mountains. Its highest elevation is the mountain Děčínský Sněžník at 726m above sea level. It has been a protected area (as ChKO Labske Piskovce) since 1972.
The region along the right side of the Elbe became a national park on January 1, 2000, the České Švýcarsko National Park. The National Park is adjacent to the Saxon Switzerland National Park (Sächsische Schweiz) in Germany.
The concept of Bohemian Switzerland developed in the 18th century as an extension of the Saxon Switzerland, the part of the Elbe Sandstone Mountains in Germany. The name was inspired by the Swiss artists Adrian Zingg and Anton Graff, who were reminded of their homeland by the geography of northern Bohemia.