Limnetica 39

Theoretical Limnology is a neglected topic nowadays. Here we make an endeavour to launch and promote theoretical developments in Limnology, dealing with the mechanistic relationships among biogeochemistry, production, species richness and food webs in the most common-sized lakes, i.e. small-to-medium ones. Although few studies are currently underway to support such relationships, well-known interactions enable us to place such lakes within a conceptual model bottom-up, which include water retention, total phosphorus and dissolved organic carbon as the driving variables. All response variables are viewed on the basis of area, which enables circumventing the otherwise important issue of depth (and hence stratification). Seven lake types are considered with unique sets of features concerning species richness, food web connectance, nutrient fluxes and lake metabolism.

The extension and tuning of this conceptual model to all stagnant waters (from small to large) can be undertaken when more data on these topics are available, probably taking horizontal transport features into account. We look forward to seeing future developments in theoretical Limnology, also paying special attention to Mediterranean limnological features which differ somewhat from those of cold temperate- and tropical areas.