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Local geology determines responses of stream producers and fungal decomposers to nutrient enrichment: A field experiment.

ABSTRACT: We examined how short-term (19 days) nutrient enrichment influences stream fungal and diatom communities, and rates of leaf decomposition and algal biomass accrual. We conducted a field experiment using slow-releasing nutrient pellets to increase nitrate (NO3-N) and phosphate (PO4-P) concentrations in a riffle section of six naturally acidic (naturally low pH due to catchment geology) and six circumneutral streams. Nutrient enrichment increased microbial decomposition rate on average by 14%, but the effect was significant only in naturally acidic streams. Nutrient enrichment also decreased richness and increased compositional variability of fungal communities in naturally acidic streams. Algal biomass increased in both stream types, but algal growth was overall very low. Diatom richness increased in response to nutrient addition by, but only in circumneutral streams. Our results suggest that primary producers and decomposers are differentially affected by nutrient enrichment and that their responses to excess nutrients are context dependent, with a potentially stronger response of detrital processes and fungal communities in naturally acidic streams than in less selective environments.

SUBMITTER: Mykra H

PROVIDER: S-EPMC6297103 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature

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Local geology determines responses of stream producers and fungal decomposers to nutrient enrichment: A field experiment.

Mykrä Heikki H Sarremejane Romain R Laamanen Tiina T Karjalainen Satu Maaria SM Markkola Annamari A Lehtinen Sirkku S Lehosmaa Kaisa K Muotka Timo T

Ambio 20180416 1

We examined how short-term (19 days) nutrient enrichment influences stream fungal and diatom communities, and rates of leaf decomposition and algal biomass accrual. We conducted a field experiment using slow-releasing nutrient pellets to increase nitrate (NO<sub>3</sub>-N) and phosphate (PO<sub>4</sub>-P) concentrations in a riffle section of six naturally acidic (naturally low pH due to catchment geology) and six circumneutral streams. Nutrient enrichment increased microbial decomposition rate ...[more]

PMID: 29663267

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Dataset Information

Local geology determines responses of stream producers and fungal decomposers to nutrient enrichment: A field experiment.

Publications

Local geology determines responses of stream producers and fungal decomposers to nutrient enrichment: A field experiment.

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