Search results for "Phytoplankton structure"
showing 2 items of 2 documents
Phytoplankton distribution along trophic gradients within and among reservoirs in Catalonia (Spain)
2008
SUMMARY 1. Longitudinal gradients in the epilimnetic waters of stratified reservoirs provide a useful database to study changing environmental conditions. The spatial distribution, assemblage structure and specific adaptations of phytoplankton assemblages can be analysed along these gradients over short time scales. 2. Four reservoirs with a similar typology, located along an altitudinal gradient in the same eco-region, were sampled along their longitudinal axes. In total, 19 sampling stations provided a trophic spectrum, ranging from oligo-mesotrophy to hypertrophy, which was quantified by calculating the trophic state index of each sampling station in the four reservoirs. 3. Several patte…
Phytoplankton assemblages in reservoirs: Is it chemical or physical constraints which regulate their structure?
1998
Data on phytoplankton assemblages and the correspondent environmental variables, collected in a limnological investigation carried out on 21 Sicilian reservoirs between 1987 and 1988, were ordered to clarify which physical (light availability, mixing depth), chemical (nutrient availability) and biological (grazing pressure) parameters modulate the structure of the assemblages. In particular, data sets were analyzed using CANOCO 3.1. The results of the analysis have shown that physical factors are more important in selecting species for those environments subject to pronounced water-level fluctuations. The reasons of such strong influence may be understood in the secondary modifications that…