This volume originated in a belief, shared by the two editors, that the time was ripe for a world-wide survey - or at least sampling - of seasonality in freshwater phytoplankton. An opportunity was provided by the International Limnological Congress (S. I. L. ), held at Lyon in August 1983, to plan a one-day symposium on the topic. From this enjoyable and successful occasion, augmented by additional written contributions, the present volume has emerged. As convenors and editors, we are grateful to the contributors for their cooperation in this international venture. The seasonality of phytoplankton is widely conditioned by that of climate. Thus one may expect to find the geographical differentiation of climatic patterns reflected in the seasonal patterns of algal occurrence. Diversity in the global perspective is also introduced by considerations of geomorphology, geochemistry, and genotypically determined response. Nevertheless, the historical base of our subject is firmly rooted in the north-temperate zone. From its fresh­ waters, and seas, there have evolved virtually all of the approaches and techniques now being applied to the analysis of phytoplankton seasonal dynamics.

Inhalt

Classic Ground: Central and Western Europe.- The periodicity of phytoplankton in Lake Constance (Bodensee) in comparison to other deep lakes of central Europe.- Succession of phytoplankton in a deep stratifying lake: Mondsee, Austria.- Seasonal variation in size spectra of phytoplankton assemblages in Loch Leven, Scotland.- Experimental manipulations of phytoplankton periodicity in large limnetic enclosures in Blelham Tarn, English Lake District.- High Northern Latitudes.- Seasonality of Melosira-plankton of the great northern lakes.- Seasonality of phytoplankton in northern tundra ponds.- Great Lakes of North America.- The seasonality of phytoplankton in the North American Great Lakes, a comparative synthesis.- Seasonality of phytoplankton in relation to silicon cycling and interstitial water circulation in large, shallow lakes of central Canada.- The Sub-Tropics and Tropics.- Phytoplankton periodicity in a subtropical lake (Lake Kinneret, Israel).- The seasonality of phytoplankton in African lakes.- Phytoplankton and its dynamics in two tropical lakes: a tropical and temperate zone comparison.- Seasonality of phytoplankton in some South Indian lakes.- Phytoplankton succession in Lake Valencia, Venezuela.- Patterns of temporal variation in Lake Titicaca. A high altitude tropical lake. I. Background, physical and chemical processes, and primary production.- The South Temperate Zone.- Phytoplankton periodicity of the Waitaki lakes, New Zealand.