Local water chemistry is the main predictor of diatom community composition
in Swedish lakes according to ordination analysis (paper I and II). Species
turnover was mainly driven by gradients in acidity (pH) and nutrient status (P
and N levels), in agreement with studies from Northern and Central Europe
(King et al. 2000, Schönfelder et al. 2002, Albert et al. 2009, Soininen and
Weckström 2009, Jüttner et al. 2010). Factors such as geography and
catchment variables (land use and hydromorphology) are important
determinants of local water chemistry (Stevenson 1997), but were of secondary
importance for benthic diatom species turnover in Swedish lakes.