Premium
Experimental nitrogen and phosphorus enrichment stimulates multiple trophic levels of algal and detrital‐based food webs: a global meta‐analysis from streams and rivers
Author(s) -
Ardón Marcelo,
Zeglin Lydia H.,
Utz Ryan M.,
Cooper Scott D.,
Dodds Walter K.,
Bixby Rebecca J.,
Burdett Ayesha S.,
Follstad Shah Jennifer,
Griffiths Natalie A.,
Harms Tamara K.,
Johnson Sherri L.,
Jones Jeremy B.,
Kominoski John S.,
McDowell William H.,
Rosemond Amy D.,
Trentman Matt T.,
Van Horn David,
Ward Amelia
Publication year - 2021
Publication title -
biological reviews
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.993
H-Index - 165
eISSN - 1469-185X
pISSN - 1464-7931
DOI - 10.1111/brv.12673
Subject(s) - trophic level , ecosystem , nutrient , river ecosystem , biomass (ecology) , environmental science , food web , ecology , autotroph , lake ecosystem , phosphorus , abundance (ecology) , primary producers , trophic state index , biology , eutrophication , environmental chemistry , chemistry , phytoplankton , genetics , organic chemistry , bacteria
Anthropogenic increases in nitrogen (N) and phosphorus (P) concentrations can strongly influence the structure and function of ecosystems. Even though lotic ecosystems receive cumulative inputs of nutrients applied to and deposited on land, no comprehensive assessment has quantified nutrient‐enrichment effects within streams and rivers. We conducted a meta‐analysis of published studies that experimentally increased concentrations of N and/or P in streams and rivers to examine how enrichment alters ecosystem structure (state: primary producer and consumer biomass and abundance) and function (rate: primary production, leaf breakdown rates, metabolism) at multiple trophic levels (primary producer, microbial heterotroph, primary and secondary consumers, and integrated ecosystem). Our synthesis included 184 studies, 885 experiments, and 3497 biotic responses to nutrient enrichment. We documented widespread increases in organismal biomass and abundance (mean response = +48%) and rates of ecosystem processes (+54%) to enrichment across multiple trophic levels, with no large differences in responses among trophic levels or between autotrophic or heterotrophic food‐web pathways. Responses to nutrient enrichment varied with the nutrient added (N, P, or both) depending on rate versus state variable and experiment type, and were greater in flume and whole‐stream experiments than in experiments using nutrient‐diffusing substrata. Generally, nutrient‐enrichment effects also increased with water temperature and light, and decreased under elevated ambient concentrations of inorganic N and/or P. Overall, increased concentrations of N and/or P altered multiple food‐web pathways and trophic levels in lotic ecosystems. Our results indicate that preservation or restoration of biodiversity and ecosystem functions of streams and rivers requires management of nutrient inputs and consideration of multiple trophic pathways.