Umeå universitets logga

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
Impacts of global change on primary production in northern lakes
Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap.ORCID-id: 0000-0003-0291-2639
2022 (Engelska)Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)Alternativ titel
Globala förändringars påverkan på primärproduktionen i nordliga sjöar (Svenska)
Abstract [en]

Algae are primary producers, a major component of the aquatic foodweb, and changes in primary production affect aquatic ecology in general. Global changes such as warming, recovery of acidification and changes in land-use have caused warming and browning of northern lakes. Warming is a direct effect of increasing air temperatures, whereas browning is mainly caused by increasing amounts of terrestrially derived colored dissolved organic carbon (DOC). Altogether, such global changes impact important environmental drivers for aquatic gross primary production (GPP). Increased temperatures and nutrient supplementation by DOC at low concentrations enhance GPP, but the browning by DOC at high concentrations inhibits GPP by light reduction, resulting in contrasting controls of global changes on primary production in northern lakes. Primary producers grow in two distinct habitats; free-floating algae (phytoplankton) and stationary periphytic (attached) algae that are restricted to use the light that reaches them. Periphyton includes algae growing on submerged surfaces ranging from nutrient-poor rocks to nutrient-rich sediments (here: benthic algae), and both often exceed pelagic GPP but are overlooked and often simply excluded from algal biomass estimates.

In this thesis, I investigate how global change influences key environmental drivers of GPP, and how those changes impact GPP in the benthic and pelagic habitat, and the sum and partitioning of GPP between these habitats (the autrotrophic structuring). I do this by interpreting a dataset with GPP measurements in several lakes over the Swedish Arctic, subarctic and boreal landscape that representa wide range of DOC concentrations. I also assess to what extent temperature and DOC impact periphytic algae growth on plastic strips in an experimental study where DOC and temperature are manipulated in 20 ponds. Besides assessing the direct impacts of changes in nutrients and light climate associated with changes in DOC, I assess indirect impacts of global changes on primary production, e.g., through intensified warming, CO2 supersaturation, changes in pH, and the role of landscape processes and properties.

Results confirm that DOC is dominant in structuring GPP in northern lakes by light inhibition, nutrient supplementation, indirect warming of surface waters, and additionally by CO2 fertilization. In addition, warming can enhance growth rates, but thermal compensation can also lead to reduced algae growth. Moreover, periphytic GPP of algae growing on both soft nutrient-rich sediments and nutrient-poor plastic strips GPP was generally much higher than pelagic GPP, and should thus not be excluded in studies assessing global change impacts on GPP. DOC affects the total GPP, as well as the autotrophic structuring in northern lakes, and likely also higher trophic levels productivity and community composition.

Ort, förlag, år, upplaga, sidor
Umeå: Umeå University , 2022. , s. 30
Nyckelord [en]
Primary production, global change, warming, browning, lake, carbon dioxide, organic carbon, inorganic carbon, boreal, arctic, DOC, DIC, CO2, allochthonous organic carbon, benthic, periphyton
Nationell ämneskategori
Naturgeografi Ekologi
Forskningsämne
miljöförändringar; miljövetenskap; biologi; klimatförändringar
Identifikatorer
URN: urn:nbn:se:umu:diva-194523ISBN: 978-91-7855-813-1 (digital)ISBN: 978-91-7855-812-4 (tryckt)OAI: oai:DiVA.org:umu-194523DiVA, id: diva2:1656949
Disputation
2022-06-03, S205, Samhällsvetarhuset, Umeå, 09:00 (Engelska)
Opponent
Handledare
Forskningsfinansiär
Knut och Alice Wallenbergs Stiftelse, 2016.0083Tillgänglig från: 2022-05-13 Skapad: 2022-05-09 Senast uppdaterad: 2022-05-24Bibliografiskt granskad
Delarbeten
1. An ecological and methodological assessment of benthic gross primary production in northern lakes
Öppna denna publikation i ny flik eller fönster >>An ecological and methodological assessment of benthic gross primary production in northern lakes
Visa övriga...
2022 (Engelska)Ingår i: Ecosphere, ISSN 2150-8925, E-ISSN 2150-8925, Vol. 13, nr 3, artikel-id e3973Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

Benthic gross primary production (GPP) is often the most important part of aquatic food webs in northern lakes, which are gradually warming and receiving increased terrestrial colored dissolved organic carbon loadings due to global change. Yet, measurements of benthic GPP are fairly uncommon, and methods and unit dimensions of benthic GPP are unstandardized and rarely compared. In this study, we measured benthic GPP in 27 headwater lakes from three regions in northern Sweden and analyzed potential constraining drivers of benthic GPPz rates at discrete depths and estimates of benthic GPP averages across the whole lake, as well as across the littoral zone. We also compared in situ measurements of benthic GPP averages across the whole lake with modeled values using the “autotrophic structuring model.” We found that benthic GPPz rates were best explained by, and positively related to, available light (i.e., a function of depth and water color) and temperature. Benthic GPP averages across the whole lake, on the contrary, were best explained by the relative size of the littoral area, which is a measure that combines lake bathymetry and water color. The comparison between in situ measured and modeled estimates of benthic GPP averages across the whole lake revealed that (1) the autotrophic structuring model underestimates GPP at low values and overestimates GPP at high values compared with measured data, and that (2) measured values were related to temperature, which is not included as a variable in the autotrophic structuring model. Considering future predicted changes impacting northern latitude lakes, our results suggest that increased lake water temperatures can to some extent mitigate the negative impacts of reduced light availability from lake browning on benthic GPPz rates. The combined impact of these changes on benthic GPP averages across the whole lake will depend on, and be moderated by, lake bathymetry determining the relative size of the littoral area.

Ort, förlag, år, upplaga, sidor
John Wiley & Sons, 2022
Nyckelord
dissolved organic carbon, freshwater, gross primary production, littoral, soft sediments, upscaling
Nationell ämneskategori
Ekologi
Identifikatorer
urn:nbn:se:umu:diva-193804 (URN)10.1002/ecs2.3973 (DOI)000776290300038 ()2-s2.0-85127526261 (Scopus ID)
Forskningsfinansiär
Knut och Alice Wallenbergs StiftelseEcosystem dynamics in the Baltic Sea in a changing climate perspective - ECOCHANGEForskningsrådet Formas
Tillgänglig från: 2022-05-06 Skapad: 2022-05-06 Senast uppdaterad: 2023-03-24Bibliografiskt granskad
2. Global change indirectly increases pelagic productivity in northern lakes by accelerating surface water warming and by reducing CO2 limitation
Öppna denna publikation i ny flik eller fönster >>Global change indirectly increases pelagic productivity in northern lakes by accelerating surface water warming and by reducing CO2 limitation
Visa övriga...
(Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
Nationell ämneskategori
Ekologi Klimatforskning Miljövetenskap Geokemi
Forskningsämne
miljövetenskap
Identifikatorer
urn:nbn:se:umu:diva-194515 (URN)
Tillgänglig från: 2022-05-09 Skapad: 2022-05-09 Senast uppdaterad: 2022-05-09
3. Landscape determinants of pelagic and benthic primary production in northern lakes
Öppna denna publikation i ny flik eller fönster >>Landscape determinants of pelagic and benthic primary production in northern lakes
Visa övriga...
2022 (Engelska)Ingår i: Global Change Biology, ISSN 1354-1013, E-ISSN 1365-2486, Vol. 28, nr 23, s. 7063-7077Artikel i tidskrift (Övrigt vetenskapligt) Published
Abstract [en]

Global change affects gross primary production (GPP) in benthic and pelagic habitats of northern lakes by influencing catchment characteristics and lake water biogeochemistry. However, how changes in key environmental drivers manifest and impact total (i.e., benthic + pelagic) GPP and the partitioning of total GPP between habitats represented by the benthic share (autotrophic structuring) is unclear. Using a dataset from 26 shallow lakes located across Arctic, subarctic, and boreal northern Sweden, we investigate how catchment properties (air temperature, land cover, hydrology) affect lake physico-chemistry and patterns of total GPP and autotrophic structuring. We find that total GPP was mostly light limited, due to high dissolved organic carbon (DOC) concentrations originating from catchment soils with coniferous vegetation and wetlands, which is further promoted by high catchment runoff. In contrast, autotrophic structuring related mostly to the relative size of the benthic habitat, and was potentially modified by CO2 fertilization in the subarctic, resulting in significantly higher total GPP relative to the other biomes. Across Arctic and subarctic sites, DIC and CO2 were unrelated to DOC, indicating that external inputs of inorganic carbon can influence lake productivity patterns independent of terrestrial DOC supply. By comparison, DOC and CO2 were correlated across boreal lakes, suggesting that DOC mineralization acts as an important CO2 source for these sites. Our results underline that GPP as a resource is regulated by landscape properties, and is sensitive to large-scale global changes (warming, hydrological intensification, recovery of acidification) that promote changes in catchment characteristics and aquatic physico-chemistry. Our findings aid in predicting global change impacts on autotrophic structuring, and thus community structure and resource use of aquatic consumers in general. Given the similarities of global changes across the Northern hemisphere, our findings are likely relevant for northern lakes globally.

Ort, förlag, år, upplaga, sidor
John Wiley & Sons, 2022
Nyckelord
autotrophic structuring, carbon fertilization, climate change, CO2, DOC, GPP, hydrology, land cover
Nationell ämneskategori
Klimatforskning Miljövetenskap Naturgeografi Geokemi
Forskningsämne
miljövetenskap
Identifikatorer
urn:nbn:se:umu:diva-194518 (URN)10.1111/gcb.16409 (DOI)000853803800001 ()36054573 (PubMedID)2-s2.0-85137981456 (Scopus ID)
Anmärkning

Originally included in thesis in manuscript form.

Tillgänglig från: 2022-05-09 Skapad: 2022-05-09 Senast uppdaterad: 2022-12-30Bibliografiskt granskad
4. Contrasting impacts of warming and browning on periphyton
Öppna denna publikation i ny flik eller fönster >>Contrasting impacts of warming and browning on periphyton
(Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
Nationell ämneskategori
Klimatforskning Miljövetenskap Naturgeografi Geokemi
Forskningsämne
miljövetenskap
Identifikatorer
urn:nbn:se:umu:diva-194520 (URN)
Tillgänglig från: 2022-05-09 Skapad: 2022-05-09 Senast uppdaterad: 2022-05-09

Open Access i DiVA

fulltext(1432 kB)163 nedladdningar
Filinformation
Filnamn FULLTEXT01.pdfFilstorlek 1432 kBChecksumma SHA-512
bff8c4a134da4335499d462270a9aa5981418f2e94b6b576ef821d6830c297e2721420eae273a58174d190041f3a1fdbe62048a5e108f4a8d78f8d449b536c4c
Typ fulltextMimetyp application/pdf
spikblad(138 kB)50 nedladdningar
Filinformation
Filnamn FULLTEXT02.pdfFilstorlek 138 kBChecksumma SHA-512
b8e52e3a736f586f126d7e3767c1b6130e706b68860f4276acb23d9ca1817bfdaf3a5d4faef8306b9d6af4f64c9c192d2be4f0745e90b3cf1725dc4e0248f376
Typ spikbladMimetyp application/pdf

Person

Puts, Isolde Callisto

Sök vidare i DiVA

Av författaren/redaktören
Puts, Isolde Callisto
Av organisationen
Institutionen för ekologi, miljö och geovetenskap
NaturgeografiEkologi

Sök vidare utanför DiVA

GoogleGoogle Scholar
Totalt: 213 nedladdningar
Antalet nedladdningar är summan av nedladdningar för alla fulltexter. Det kan inkludera t.ex tidigare versioner som nu inte längre är tillgängliga.

isbn
urn-nbn

Altmetricpoäng

isbn
urn-nbn
Totalt: 1136 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