Bacterioplankton responses to increased organic carbon and nutrient loading in a boreal estuary—separate and interactive effects on growth and respiration

Research output: Contribution to journalArticle

Abstract

Increases in the terrestrial export of dissolved organic carbon (C) to rivers may be associated with additional loading of organic nitrogen (N) and phosphorus (P) to the coastal zone. However, little is known about how these resources interact in the regulation of heterotrophic bacterioplankton metabolism in boreal coastal ecosystems. Here, we measured changes in bacterioplankton production (BP) and respiration (BR) in response to full-factorial (C, N, and P) enrichment experiments at two sites within the Öre estuary, northern Sweden. The BR was stimulated by single C additions and further enhanced by combined additions of C and other nutrients. Single addition of N or P had no effect on BR rates. In contrast, BP was primarily limited by P at the site close to the river mouth and did not respond to C or N additions. However, at the site further away from the near the river mouth, BP was slightly stimulated by single additions of C. Possibly, the natural inflow of riverine bioavailable dissolved organic carbon induced local P limitation of BP near the river mouth, which was then exhausted and resulted in C-limited BP further away from the river mouth. We observed positive interactions between all elements on all responses except for BP at the site close to the river mouth, where P showed an independent effect. In light of predicted increases in terrestrial P and C deliveries, we expect future increases in BP and increases of BR of terrestrially delivered C substrates at the Öre estuary and similar areas.

Details

Authors
Organisations
External organisations
  • Lund University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Microbiology
  • Ecology

Keywords

  • Bacterial metabolism, Bacterial production, Bacterial respiration, Nutrient interactions, Nutrient limitation, Terrestrial dissolved organic matter
Original languageEnglish
Pages (from-to)144-155
Number of pages12
JournalMicrobial Ecology
Volume76
Issue number1
Publication statusPublished - 2018 Jul 1
Publication categoryResearch
Peer-reviewedYes

Related projects

View all (1)