Factors controlling the seasonal development and distribution of the phytoplankton community in the lowland course of a large river in Northern Italy (River Adige)

Salmaso, N; Braioni, M

HERO ID

3608335

Reference Type

Journal Article

Year

2008

Language

English

HERO ID 3608335
In Press No
Year 2008
Title Factors controlling the seasonal development and distribution of the phytoplankton community in the lowland course of a large river in Northern Italy (River Adige)
Authors Salmaso, N; Braioni, M
Journal Aquatic Ecology
Volume 42
Issue 4
Page Numbers 533-545
Abstract The principal environmental factors influencing the seasonal dynamics of phytoplankton were examined from September 1997 to July 1998 in three stations along a 26-km stretch of the lowland course of River Adige (northeast Italy). Nutrient concentrations did not appear to be limiting for the phytoplankton growth. Annual minimum concentrations of reactive and total phosphorus, and dissolved inorganic nitrogen were 22 mu g P l-1, 63 mu g P l-1 and 0.9 mg N l-1, respectively. The most critical forcing factors were physical variables, mainly water discharge and other variables related to hydrology, i.e. suspended solids and turbidity, which acted negatively and synchronously by diluting phytoplankton cells and decreasing light availability. Higher algal biomass was recorded in early spring, in conditions of lower flow velocity and increasing water temperature. In late spring and summer, higher water discharge caused a decrease in phytoplankton biomass. Conversely, low algal biomass in late autumn and winter, during low discharge, was mainly related to low water temperatures and shorter photoperiod. Physical constraints had a significant and measurable effect not only on the development of total biomass, but also on the temporal dynamics of the phytoplankton community. Abiotic and biotic variables showed a comparable temporal development in the three sampling stations. The small number of instances of spatial differences in phytoplankton abundance during the period of lower flow velocity were related to the increasing importance of biological processes and accumulation of phytoplankton biomass.
Doi 10.1007/s10452-007-9135-x
Wosid WOS:000260834900003
Is Certified Translation No
Dupe Override No
Is Public Yes
Language Text English