These proceedings deal with the relationship between species composition of freshwater phytoplankton and the trophic gradient. Particular regard is paid to the composite question, what lives where and why? Overview papers report the state of the art and suggest that the trophic spectrum appears to be a probabilistic outcome of several dimensions of variability that impinge upon phytoplankton species selection. Studies on community structure span all latitudes from those of Antarctica to equatorial Brazil, and also include reports on light and nutrient gradients, pH and fish-stock effects on species composition. Seasonal and longterm phytoplankton dynamics in lakes of varying trophic status are also considered. Finally, studies on the taxonomy and autoecology of some groups (e.g. Volvocales, Chrysophytes and Euglenophytes) living at the extremes of the trophic spectrum contribute to our knowledge of this usually neglected phytoplankton.
This is the first time that a book covers such a topic, and it will prove an excellent source of information to anyone working on phytoplankton ecology and ecological indicators. Limnologists in general, algologists and the technical staff at water authorities will all benefit by reading this book.

Auteur
Jørgen Kristiansen, Associate Professor (Emeritus) at the Section of Phycology, Department of Biology, University of Copenhagen has studied chrysophyte algae in many parts of the world. He has given lectures and courses on chrysophytes on several universities, congresses and symposia, and is author or co-author of about 200 publications, including several books.

Résumé
Proceedings of the 10th Workshop of the International Association of Phytoplankton Taxonomy and Ecology (IAP), held in Granada, Spain, 21-29 June 1996

Contenu
Species Selection in Relation to Tropic Gradients.- Differential attributes of phytoplankton across the trophic gradient: a conceptual landscape with gaps.- What factors influence the species composition of phytoplankton in lakes of different trophic status?.- Processes in the Assembly of Communities.- Summer phytoplankton assemblages across trophic gradients in hard-water reservoirs.- Phytoplankton of two Araucanian lakes of differing trophic status (Argentina).- Phytoplankton species composition is more sensitive than OECD criteria to the trophic status of three Brazilian tropical lakes.- Phytoplankton communities in relation to trophic status in lakes from Hope Bay (Antarctic Peninsula).- The most typical phytoplankton taxa in four types of boreal lakes.- Phytoplankton composition and biomass structure in relation to trophic gradient in some temperate and subarctic lakes of north-western Russia and the Prebaltic.- Ecophysiological characteristics of two planktonic desmid species originating from trophically different lakes.- Freshwater picocyanobacteria along a trophic gradient and light quality range.- Responses of the phytoplankton to a deliberate attempt to raise the trophic status of an acidic, oligotrophic mountain lake.- Comparative study of phytoplankton in an oligotrophic soft water lake under different pH-phosphate ranges.- Fish stock as a variable modifying trophic pattern of phytoplankton.- Seasonal and Long-Term Dynamics.- Seasonality of phytoplankton as an indicator of trophic status of the large perialpine 'Lago di Garda'.- Phytoplankton dynamics in two reservoirs with different trophic state (Lake Rosamarina and Lake Arancio, Sicily, Italy).- Phytoplankton succession in the oligotrophic Lake Stechlin (Germany) in 1994 and 1995.- Grazing by largeriver zooplankton: a key to summer potamoplankton decline? The case of the Meuse and Moselle rivers in 1994 and 1995.- The phytoplankton succession in the lower part of hypertrophic Nakdong River (Mulgum), South Korea.- Success of chrysophytes, cryptophytes and dinoflagellates over blue-greens (cyanobacteria) during an extreme winter (1995/96) in eutrophic shallow lakes.- Structural changes during eutrophication of Lake Balaton, Hungary, as revealed by the Zipf-Mandelbrot model.- Trends and relations among basic phytoplankton characteristics in the course of the long-term oligotrophication of Lake Maggiore (Italy).- Development of the phytoplankton of the shallow Srebarna Lake (north-eastern Bulgaria) across a trophic gradient.- Taxonomy and Ecology of Photosynthetic Flagellates.- Life-cycle studies and culture experiments for identification of doubtful volvocacean organisms observations on Pandorina and Eudorina.- Morphological changes of Euglenophyta in response to organic enrichment.- Specific composition and ecology of chrysophyte flagellates in Lake Sanabria (NW Spain).- Taxonomic remarks on planktonic phytoflagellates in a hypertrophic tropical lagoon (Brazil).- Chrysophytes and Chlamydomonads: pioneer colonists in extremely acidic mining lakes (pH