326 FOLIA GEOBOTiNICA AND PHYTOTAXOxNOMICA 19, 1984

B o o k r e v i e w

CATAR~I~A JOHANSSON

A T T A C H E D A L G A L V E G E T A T I O N I N R U N N I N G W A T E R S OF J A M T L A N D , S W E D E N .

Acta Phytogeographica Suecica, Nr. 71, Ed. Svenska V~xtgeografiska S/illskapet, Uppsala 1982, 83 pp., 14 tables, 65 figures.

The use of algae as indicators of environmental conditions in running waters is an important part of many contemporary studies in algal ecology. In Sweden, there is an old tradition of eco- logical studies of this type and many Swedish streams have been investigated by prominent algo- logists.

The present volume, prepared by C. JOEA~CSSOX, brings the results of investigations carried out during the summer seasons of 1975-- 76 at 501 stations in a research area in the province of Jgmtland, Central Sweden. Algae were collected by scraping off various substrata. By taxonomical analysis, 314 taxa have been identified, mostly Bacillariophyceae, Cyanophyta and Chlorophyta.

Paralel to the algological analysis, the environmental parameters of the individual stations were followed: the altitude of the stations, width, length, depth, current velocity, size and surface of the rivers, texture and chemistry of t he substrate, temperature, conductivity, pH, hardness and colour of water, moss cover, nutrient conditions, encrustations, insolation and sm'rounding biotopes with their vegetation.

The whole set of data on 501 streams and 314 algal species determined has been treated by several numerical methods such as cluster analysis, component and discriminant analysis, statis- tical tests and analysis of species distribution by the Kolmogorov approach.

Special a t tent ion is also paid to the classification and ordination of algal communities, also using mathematical numerical methods. Communities distinguished in the region are compared with those in other parts of Europe.

The volume, based also on a wide selection of literature and equipped with good and instructive illustrations, is a highly useful contribution to our knowledge of algal ecology in running waters

OLDf~ICH L~rOT.~K~