E. Hornstrom et al., PLANKTON AND CHEMICAL PHYSICAL DEVELOPMENT IN 6 SWEDISH WEST-COAST LAKES UNDER ACIDIC AND LIMED CONDITIONS, Canadian journal of fisheries and aquatic sciences, 50(4), 1993, pp. 688-702
Increases in pH from 4.5-5.3 to 7-7.6 after liming (1978-85) in six ac
idified lakes in the west coast area of Sweden caused increased concen
tration of humic compounds and decreased transparency compared with le
vels before liming. Concentrations of total P increased markedly where
as those of NO3-N decreased. The phytoplankton composition changed com
pletely in all lakes shortly after liming, but a species richness simi
lar to that in unacidified lakes was not reached until after 2-5 yr, a
nd in the previously most acidified lakes, several species remained ab
sent. The composition of the phytoplankton indicated increased primary
production. The volumetric dominance within the zooplankton shifted g
enerally from Eudiaptomus-Holopedium to Cyclops-Daphnia. The occurrenc
e of Rotatoria and Cladocera species increased and the composition bec
ame similar to that in unacidified lakes 2-5 yr after liming. The biot
ic development is largely explained by chemical-physical changes such
as increased pH, reduced Al concentration, increased P concentration,
and increased organic content, particularly humus.