The study in paper IV was conducted in
three boreal rivers in southern Finland.
Epilithic, epiphytic and epipelic diatoms
were sampled monthly at four sampling
stations from June to October. Sampled
rivers were impacted mainly by nutrients
from agriculture and by nutrients and
organic compounds from treated sewage.
River Keravanjoki was sampled at two
stations, River Porvoonjoki and River
Mustijoki at one station.
In paper VI, the study sites consisted of
eutrophic or moderately nutrient rich rivers
and some smaller, less eutrophic streams
situated in southern Finland. Most of the
rivers drained cultivated land, and
consequently were rather turbid. Epilithic
diatoms were collected at 52 sampling
stations between 1997 and 2000. Benthic
macroinvertebrates were sampled at 22
stations in years 2000 and 2002