Ecosystem Modelling

(Mariana Hill, Markus Pahlow)

We work with a wide range of ecosystem models on various scales, including local, regional, and global (Earth-system) models. We consider biochemical to whole-ecosystem processes across a wide range of trophic levels. Key interests are the development and improvement of classical NPZD-type and trait-based models, as well as the development of new theoretical concepts, such as evolutionary principles (optimality-based behaviour). This includes the representation of interactions among marine biogeochemistry, ecology and the physical circulation. We work on model development in the following areas:

  • local and 0D modelling: simulations of time-series sites and lab experiments, where observations are considered to investigate model performance and to improve/refine model formulations, often by applying procedures of parameter estimation.
  • regional end-to-end modelling: CROCO-BioEBUS, a regional lower trophic level model of the eastern equatorial Pacific coupled to a complex higher trophic level model that resolves the key species of that region including the full live cycle of fish (and fish schools)
  • global modelling: expanding the ecosystem representation of typical lower trophic level models (NPZD) in a computationally feasible way, by focussing on specific ecosystem aspects, such as vertical migration, mesopelagic fish, …
  • optimality-based modelling: variable stoichiometry and photo-acclimation in primary production; feeding thresholds and variable assimilation efficiency in zooplankton
  • trait-based modelling: adaptation of behaviour in plankton ecosystems, e.g., diel and seasonal vertical migration in zooplankton


  • Markus Pahlow: Optimality- and trait-based descriptions of acclimation, behaviour and adaptation in OPPLA (optimality-based plankton model) and UVic-OPEM (variable stoichiometry in phytoplankton, optimal foraging in zooplankton in UVic)
  • Mariana Hill: Fish models including individual-based approaches such as OSMOSE; coupling higher trophic levels to regional biogeochemical models
  • Chia-Te Chien: Sensitivity analyses and ensemble simulations for UVic-OPEM
  • Markus Schartau: Plankton size spectra - e.g. microARC ; microbial loop dynamics; formation and fate of marine microgels; organic matter accumulation within sea surface microlayer - e.g. Biogeochemical processes and Air-sea exchange in the Sea-Surface microlayer
  • Iris Kriest: Global model assessment and sensitivity studies with respect to various parameterisations
  • Tianfei Xue: Plankton dynamics analysis using regional (CROCO-BioEBUS) and global (CMIP) models
  • Julia Getzlaff: Mesopelagic ecosystem, vertical migration (CO2Meso), global modelling (UVic 2.9) (affiliated)