BIO-8 Lecture Notes - Lecture 16: Riparian Zone, Littoral Zone, Allochthon
Document Summary
Aquatic biomes are categorized by their flow, depth, and salinity. Stream (or creek): a narrow channel of fast-flowing fresh water. River: a wide channel of slow-flowing fresh water. Downstream, ecosystems are more nutrient-rich, complex, and productive. Streams support fewer species than other aquatic biomes. Small streams are often shaded and nutrient poor, which limits primary productivity. Riparian zone: terrestrial vegetation alongside rivers and streams that is influenced by seasonal flooding and elevated water tables. Allochthonous: inputs of organic matter, such as leaves, that come from outside of an ecosystem (e. g. , from a riparian zone). Autochthonous: inputs of organize matter that are produced by algae and aquatic plants inside an ecosystem. Much of the organic matter in streams in allochthonous, whereas organic matter in rivers is autochthonous. Rivers typically accumulate sediments from land, and high turbidity can block light and reduce primary production. Dams are built to control flooding, provide water for irrigation, or to generate electricity.
