CLIMATIC GOVERNANCE OF THE LATITUDINAL CLINE IN SEASONALITY OF FRESH-WATER PHYTOPLANKTON PRODUCTION

Data on the intra-annual variation in phytoplankton production for 114 southern and northern hemisphere lakes (42-degrees-S to 75-degrees-N) were combined to examine broad-scale latitudinal trends. Much of the seasonal variation in production can be statistically explained through the climatic factors of mean annual range of atmospheric temperature and annual variance in incident solar radiation, of which the amplitude of both increases with distance from the equator. Quantification of this latitudinal-climatic trend is an important step in understanding the hierarchial regulation of variability in lake trophic dynamics.