Can we aggregate the 20’000 existing phytoplankton species to few groups with similar ecological niches? This new study characterizes the ecological niches of 133 taxa on the global scale based on extensive observational datasets compiled from several sources. The similarity of niches is tested for plankton functional types (PFTs) and categories in Reynolds C-S-R model.
The existing knowledge about the global distributions patterns of phytoplankton largely originates from remote sensing and ecosystem models. In these approaches phytoplankton diversity is aggregated to few plankton functional types (PFTs), groups of species which share a certain set of traits. In the case of ecosystem models, PFTs are defined to encompass organisms that play a similar role in ocean biogeochemistry, for instance calcification in the case of coccolithophores. Phytoplankton diversity has also been aggregated based on more ecological criteria: In his C-S-R model, Reynolds assigns one of three fundamental strategies to open ocean phytoplankton species, representing adaptations either to enhanced competition under benign conditions, to nutrient stress tolerance or to light stress tolerance.
In this study Philipp, Mark and co-authors test whether the diverse taxa in a PFT or a category of Reynolds’ C-S-R model occupy similar ecological niches. The assessment is based on the MAREDAT initiative, an extensive global dataset of plankton observations composed from several sources. With the species distribution model MaxEnt they characterize the realized niches of 133 taxa, and find a considerable variability within the tested groups.
Link:
http://onlinelibrary.wiley.com/doi/10.1002/lno.10074/abstract