Phytoplankton association patterns in the deep southern subalpine lakes (Part 2)

The three following papers constitute the second, and final, part of a series of papers dedicated to the phytoplankton of the deep subalpine Italian lakes (DSL). The first part, comprising an introduction and three papers on lakes Garda, Como and Maggiore respectively, was published in the volume 61 (1) of this journal (J. Limnol., 61). The research, carried out for three years (two years in L.Como) in the period 1997-2000, was a concerted effort by investigators of five Insitutes in Italy and Switzerland. It was generated by the awareness that, despite the large number of papers existing on the phytoplankton of the single DSL, those of a comprehensive nature are very few, and by the perceived interest of a comparative investigation on the phytoplankton of the large lakes in the Insubrian district in the light of the recent progress on the ecology of the freshwater algae. So, in the final paper following those on lakes Iseo and Lugano an effort is made to compare and characterize the different species assemblages in the background of geographical and morphological characteristics, and of recent changes in trophic gradients. Despite often important differences in these respects, and observed various community responses, a common pool of species seems to be identifiable in the district.