Jørgen Kristiansen – författare

This book is based on a workshop on biogeography of freshwater algae held during the Fifth International Phycological Congress in China 1994. A group of outstanding specialists covering widely different approaches to the subject have been brought together, and this collection of their contributions forms a unique volume: there is no other book on the subject. It thus fills an evident gap in the phycological literature, and will be of major interest to researchers and teachers within phycology, limnology, and evolutionary biology. However, it may also be useful in courses for advanced students.

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.

This volume deals with the Synurophyceae, a group of silica scaled chrysophyte algae. Taxonomy within this class is based on the ultrastructure of the silica scales and bristles, and electron microscopy is in most cases necessary for the identification. Even though the 128 taxa occurring in Europe are emphasized and details of their distribution are given, the volume includes all taxa described worldwide. Thus it is possible to identify all 212 taxa with a high degree of certainty (i.e., 180 taxa of Mallomonas, 30 taxa of Synura, plus the single species of Chrysodidymus and Tessellaria). The importance of this book lies in four main fields:It can be used for the identification of synurophycean taxa in all parts of the world.It will be of particular significance in phytoplankton investigations on diversity and ecology of lakes and ponds. Many species can serve as ecological indicators, and the species-specific silica scales and cysts preserved in sediments can be useful paleobiological indicators for reconstructing a wide variety of human influences on aquatic ecosystems, including acidification, eutrophication and climate change. Last but not least, the book gives a solid basis for further taxonomical studies based on gene sequences. This is the first modern world-comprehensive book on the subject. It will be indispensable for phycologists, but should also find its way to general botanical libraries.

This book is based on a workshop on biogeography of freshwater algae held during the Fifth International Phycological Congress in China 1994. A group of outstanding specialists covering widely different approaches to the subject have been brought together, and this collection of their contributions forms a unique volume: there is no other book on the subject. It thus fills an evident gap in the phycological literature, and will be of major interest to researchers and teachers within phycology, limnology, and evolutionary biology. However, it may also be useful in courses for advanced students.