Applications of freshwater diatoms to geographical research

Abstract

Diatoms (Bacillariophyceae) are a widely distributed group of microscopic, unicellular algae that are characterized by siliceous cell walls (frustules). The size, shape and sculpturing of diatom frustules are taxonomically diagnostic. Moreover, because of their siliceous composition, diatoms are often well preserved in stratigraphic deposits, where they can be used to infer (quantitatively or qualitatively) past environmental conditions. The sensitivity of diatoms to a wide variety of environmental variables provides geographers with a multitude of research opportunities. This review focuses on palaeoecological reconstructions that are based on freshwater diatoms. Geographical applications including studies of climatology, hydrology, geomorphology, bio geography, and water-quality assessment and monitoring are discussed.