umu.sePublikationer
Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Inverse relationship of benthic algae and pelagic phosphorus in unproductive lakes: roles of N2 fixers and light
Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.
Visa övriga samt affilieringar
(Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
Nationell ämneskategori
Ekologi
Identifikatorer
URN: urn:nbn:se:umu:diva-111298OAI: oai:DiVA.org:umu-111298DiVA, id: diva2:869003
Tillgänglig från: 2015-11-12 Skapad: 2015-11-12 Senast uppdaterad: 2018-06-07
Ingår i avhandling
1. Biomass patterns in boreal-subarctic lake food webs along gradients of light and nutrients
Öppna denna publikation i ny flik eller fönster >>Biomass patterns in boreal-subarctic lake food webs along gradients of light and nutrients
2015 (Engelska)Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

There is large natural variation in light and nutrient conditions across lakes. In the boreal-subarctic region most lakes are small, shallow and nutrient poor. In such lakes there is often sufficient light to support primary production at the lake bottom. An expectation for the future is that colored dissolved organic matter (cDOM) of terrestrial origin will increase in these lakes. cDOM depresses the underwater light climate but is often associated with elevated pelagic nutrient concentrations.

A dynamical model of a coupled benthic-pelagic food web was explored for how lake ecosystems might respond to altered light and nutrient regimes. The model predicts that mobile carnivores (fish) control grazers and release primary producers from grazing pressure. Primary producers are therefore limited by their resources and cross-habitat interactions are dominated by spatially asymmetric competition for light and nutrients. At high light and low nutrient supply benthic algae out-compete pelagic algae for nutrients diffusing from the sediment, whereas pelagic algae shade out benthic algae at lower light and/or higher nutrient supply. Biomass patterns of benthic and pelagic consumers follow the patterns of primary production. In contrast, habitat coupling through carnivore movement has only a weak impact on biomass patterns in the model food web.

Model predictions were compared with data from boreal-subarctic lakes covering a broad range of cDOM concentrations. In agreement with model expectations the following relationships with increasing light attenuation were observed: benthic primary and secondary production decreased, pelagic primary production showed a unimodal trend, and pelagic nutrient concentrations as well as the proportion of fish feeding in the pelagic habitat increased. As a consequence, both primary and fish production were negatively related to pelagic nutrient concentrations across lakes.

In a comparative study of boreal-subarctic lakes covering a broad range of cDOM concentrations, a similar negative relationship was found between pelagic total nutrient concentrations and the biomass of epilithic algae. This was surprising, because epilithon cannot access nutrients from the sediment. Patterns in epilithon biomass were largely driven by nitrogen fixing cyanobacteria, which in turn were positively related to light supply. The data suggest that nitrogen fixing autotrophs may have a competitive advantage over other epilithic primary producers in low-cDOM, low-nutrient, high-light environments, and that patterns in epilithic biomass, nutrient sequestration and elemental stoichiometry depend upon which functional group is dominant in the epilithic biofilm.

Ort, förlag, år, upplaga, sidor
Umeå: Umeå universitet, 2015. s. 14
Nyckelord
boreal-subartic lake, cDOM, epilithon, benthic-pelagic coupling, carnivores
Nationell ämneskategori
Ekologi
Identifikatorer
urn:nbn:se:umu:diva-111299 (URN)978-91-7601-343-4 (ISBN)
Presentation
2015-10-15, Hörsal N320, Naturvetarhuset, Umeå universitet, Umeå, 10:00 (Engelska)
Opponent
Handledare
Tillgänglig från: 2015-11-13 Skapad: 2015-11-12 Senast uppdaterad: 2018-06-07Bibliografiskt granskad

Open Access i DiVA

Fulltext saknas i DiVA

Personposter BETA

Thomsson, GustafDiehl, SebastianKarlsson, JanLiess, Antonia

Sök vidare i DiVA

Av författaren/redaktören
Thomsson, GustafDiehl, SebastianKarlsson, JanLiess, Antonia
Av organisationen
Institutionen för ekologi, miljö och geovetenskap
Ekologi

Sök vidare utanför DiVA

GoogleGoogle Scholar

urn-nbn

Altmetricpoäng

urn-nbn
Totalt: 165 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf