title: Transformation of a tundra river from heterotrophy to autotrophy by addition of phosphorus.
abstract: Continuous enrichment of an arctic river with only 10 parts per billion phosphate-phosphorus caused an immediate growth of attached algae for more than 10 kilometers downstream, showing that phosphorus alone limited photosynthesis. As a result of the increased photosynthesis, there was an increase in bacterial activity in films on rocks on the bottom of the stream. The major source of energy became the photosynthetic carbon fixed in the stream rather than the organic material entering from the surrounding tundra, and the overall metabolism of the stream shifted from heterotrophy to autotrophy. An increase in the size and developmental stage of some of the dominant aquatic insects illustrates the food limitation in this nutrient-poor habitat.
authors.forename: B J
authors.initials: BJ
authors.lastname: Peterson
authors.forename: J E
authors.initials: JE
authors.lastname: Hobbie
authors.forename: A E
authors.initials: AE
authors.lastname: Hershey
authors.forename: M A
authors.initials: MA
authors.lastname: Lock
authors.forename: T E
authors.initials: TE
authors.lastname: Ford
authors.forename: J R
authors.initials: JR
authors.lastname: Vestal
authors.forename: V L
authors.initials: VL
authors.lastname: McKinley
authors.forename: M A
authors.initials: MA
authors.lastname: Hullar
authors.forename: M C
authors.initials: MC
authors.lastname: Miller
authors.forename: R M
authors.initials: RM
authors.lastname: Ventullo
authors.forename: G S
authors.initials: GS
authors.lastname: Volk