PhD forsvar af Erik Mousing – University of Copenhagen

25. november 2013

PhD forsvar af Erik Mousing

Macroecological patterns in the distribution of marine phytoplankton – patterns and processes with regard to size, biomass and diversity

Tid: 12. december 2013 kl. 13.00

Sted: Biologisk Institut. Universitetsparken 15, Bygning 1, Auditorium A, 2100 Ø

Institut: Biologisk Institut

Vejledere: Professor Katherine Richardson and Professor Marianne Ellegaard

Bedømmelses komité: Dr. Nina Lundholm, Københavns Universitet (Chair), Professor John Raven, University of Dundee, Scotland and Professor Tron Frede Thingstad, Bergens Universitet, Norge

Abstract:
Changes in phytoplankton community composition can have cascading effects on food web dynamics, primary production, biochemical cycling and have a direct impact on the global carbon cycle through the biological pump. Understanding the processes controlling phytoplankton community dynamics at the global scale and how these interact with climate are, therefore, imperative for prediction future ocean function.

The primary focus of this thesis has been to describe macroecological patterns in phytoplankton total biomass and community size structure and relate these patterns to in situ abiotic conditions (primarily temperature, salinity, mixed layer dynamics and ambient nutrient concentrations) in order to elucidate the primary bottom-up processes that control phytoplankton communities. Several data sets are investigated at both the spatial and temporal scales; macroecological patterns are investigated on the global scale through a data set collected on the circumnavigating Galathea 3 expedition. Specific hypotheses on phytoplankton size, silica recycling and bloom dynamics are investigated using more confined datasets collected in the North Atlantic, in the Disko Bay, Greenland and in the Black Sea.

Together the results show that macroecological investigations of phytoplankton distributions has tremendous potential in terms of developing an understanding of fundamental processes relating to phytoplankton community dynamics and carbon uptake by photosynthesis in the ocean.