Half-century trends in alpha and beta diversity of phytoplankton summer communities in the Helsinki Archipelago, the Baltic Sea.

We analyzed phytoplankton biodiversity trends in a 52 year (1967-2018) monitoring time-series from the archipelago of Helsinki, Gulf of Finland, the Baltic Sea. The community ordination revealed strong ordering of samples along the time axis (generalized additive model-gam fit:  = 0.9).