The focus of eutrophication research has tended to be upon short-term
and experimental studies. However, given the range of factors that can
influence eutrophication dynamics, and that these matter over a range
of time scales, some discrete, some continuous, eutrophication dynamics
may only be fully investigated when long-term, time-series data are
available. The present study aims to evaluate the interacting effects
of abiotic processes and biotic dynamics in explaining variations of
phytoplankton biomass in a eutrophic shallow lake, Barton Broad
(Norfolk, UK) using a long-term data set. Multivariate statistical
analysis shows that the inter-relationships between phytoplankton
variability, nutrient and grazing factors were highly sensitive to
seasonal periodicity. In spring phytoplankton biomass was related to
phosphorus, nitrogen and silicon. In summer phytoplankton biomass was
associated with phosphorus, nitrogen and zooplankton. In autumn
phytoplankton was related to phosphorus, nitrogen, silicon and
zooplankton. In winter, no significant relationship could be
established between phytoplankton and environmental variables. This
paper improves our understanding of the governing role of nitrogen,
phosphorus, silicon and zooplankton upon phytoplankton variability, and
hence, improves management methods for eutrophic lakes. (C) 2002
Elsevier Science B.V. All rights reserved.