Influence of Temperature Changes on Aquatic Ecosystems: An Interpretation of Empirical Data

Many mathematical relationships have been used to summarize quantitative information about the effects of temperature on rate processes in ectothermic living systems. One of the more common relationships, which has been used for a century, is here termed the “combined exponential model.” An exponential model, as with a first-order chemical reaction, is used to define a coefficient for a rate at a particular temperature; another exponential relationship (of the vanˈt Hoff or the Arrhenius form) is then used to relate the coefficients of the rate process to their respective temperatures. The Arrhenius form has come to be preferred over the vanˈt Hoff form. In ectotherm physiology, the combined exponential model applies when the relevant organism has not evolved means of compensating biologically for the underlying physicochemical dynamics as affected by temperature, Here we assess the applicability of the combined model, of the Arrhenius form, to analogous ecological situations for aquatic ectothermic populations and ecosystems. On an empirical basis, we find that this combined model has some utility in that it permits approximate assessments of some ecosystemic effects of climate warming.