Effects of increased pCO2 and terrestrial organic matter on phytoplankton and bacterioplankton activity and dynamics: A microcosm experiment on natural microbial assemblages
Independent thesis Advanced level (degree of Master (Two Years)), 40 credits / 60 HE creditsStudent thesis
In the light of predicted climate change scenarios, atmospheric and water CO2 partial pressure (pCO2), as well as precipitations, are expected to increase during the next decades. High-latitude water masses, such as the Baltic Sea, are more susceptible to be affected by the increase of these two environmental factors due to the high solubility of CO2 in cold water and the greater input of terrestrial matter from the rivers. We carried out a microcosm experiment in order to test the single and combined effects of increasing CO2 and terrestrial organic matter (TOM) on natural phytoplankton and bacterioplankton assemblages present in the seawater from a coastal area in the Gulf of Bothnia. Our results suggest no interaction between pCO2 and TOM, but strong effects of TOM on microbial dynamics. On the other hand, pCO2 did generally not show effects on either trophic group, suggesting a less important role compared to organic matter inputs under climate change scenarios. We also observed an uncoupling between phytoplankton and bacterioplankton dynamics among all the treatments.
Place, publisher, year, edition, pages
2015. , 23 p.
Climate change, CO2, TOM, phytoplankton, bacterioplankton
IdentifiersURN: urn:nbn:se:umu:diva-105088OAI: oai:DiVA.org:umu-105088DiVA: diva2:823239
Master's Programme in Ecology
2015-06-05, KB5C2, Linnaeus väg 6 (KBC), Umeå University, SE- 901 87 Umeå, Umeå, 21:36 (English)
Ask, Jenny, PhD
Byström, Pär, Senior lecturer