The relationship between functional anatomy of lakes and primary production

The morphology of a lake and exchanges of energy across its boundaries together constitute its functional anatomy. The amount and variability of primary production are related to this functional anatomy. This relationship involves preferential scales, intervals that can be characterized by non-linear functions, time delays and changes of phase. The larger the volume of reference and the sharper the boundaries, the more significant the link between functional anatomy and primary production. Dynamic physical and biological models must include the development of functions and estimation of parameters in certain characteristic intervals but must also forecast where (or when) qualitative or abrupt changes could appear. For research on intralake variability of primary production special attention should be paid to the relative duration of successive stable and unstable phases. In interlake studies, lakes having functional anatomy with features which determine sporadic ice-formation, meromixis, seasonal thermocline, etc. would show les s predictable variability in primary production than lakes with a regular annual pattern. In extreme cases, low frequency fluctuations can lead to completely new biological systems.