While the development in concepts and techniques over the last decade(s) have fundamentally changed our appreciation of the qualitative and quantitative role of micro-organisms in the flows of matter and energy through pelagic food webs, it is probably fair to say that our understanding of the mechanisms regulating the magnitude and directions of these flows still remain obscure. We here suggest that main features of this complex system can be understood from a fairly simple conceptual model unifying otherwise apparently contradicting aspects. At the same time, however, the pelagic food web also contains aspects where we see potential conflicts between such a simple conceptual model and present observations. There are also aspects of the microbial part of this system where fundamental knowledge on the biological processes is still lacking.
We thus propose a project where the aim is to:
- explore the explanatory power of the proposed conceptual model for ecosystem experiments and descriptions,
- collect data we feel are crucial for progressing towards a more quantitative formulation of the conceptual model,
- critically look at specificmechanisms which presently seem difficult to incorporate into this simple conceptual framework, and
- study specific processes in the food web we feel are too poorly understood to incorporate in a correct manner.
As a research strategy for this evaluation and modification of our concepts of microbial food web functioning, we propose a combination of:
- experimental approaches,
- field measurements, and
- small scale mathematical modelling.