HOW IMPORTANT ARE PIGMENTS FOR PHYTOPLANKTON BIOGEOGRAPHY?
Light is fundamental for photosynthesis and becomes a limiting resource in almost all global oceans. Consequently, the intracellular pigments that govern the efficiency of light absorption are likely to be important functional traits that impact phytoplankton distributions. However, the importance of pigments for species selection compared to other factors, such as nutrient availability or temperature, remains unclear. We use a numerical model to explore how the optical properties of different phytoplankton functional types contribute to setting their global horizontal and vertical distributions. The model resolves a three-stream radiative transfer of photosynthetically available radiation (PAR, 400-700nm), which is dependent on the spectral absorption and scattering properties of water, phytoplankton, detritus and coloured dissolved organic matter (CDOM). Sensitivity experiments reveal that the specific light absorption spectra are very important in determining the competiveness of the different phytoplankton, the ecosystem structure, and the feedback to biogeochemistry. When absorption spectra are the only difference between types we find evidence of both competitive exclusion and coexistence. However, though important, the chromatic adaptation between species has co-evolved (or is energetically determined) along with other traits.
Hickman, A. E., University of Southampton, United Kingdom, email@example.com
Dutkiewicz, S., Massachusetts Institute of Technology, USA, firstname.lastname@example.org
Jahn, O., Massachusetts Institute of Technology, USA, email@example.com
Follows, M. J., Massachusetts Institute of Technology, USA, firstname.lastname@example.org
Time: 16:00 - 18:00
Location: Poster/Exhibit Hall
Presentation is given by student: No