Unexpected shift from cyanobacterial to dinoflagellate dominance due to a summer drought

The ruling paradigm is that future climate change scenarios will lead to an increase in the frequency, intensity, and duration of cyanobacterial blooms across the globe. It was therefore unexpected when, during an unusually warm and dry summer in southern Sweden in 2018, cyanobacteria did not dominate the phytoplankton community of the temperate Lake Vombsjön known for toxic cyanobacterial blooms. Instead, a potentially toxic dinoflagellate, Naiadinium polonicum, formed a large bloom and was dominant for the entire season. Dinoflagellates share important functional traits with cyanobacteria, but few studies have considered competition between dinoflagellates and cyanobacteria under future climate change scenarios. In order to understand the underlying factors leading to the N. polonicum bloom in 2018, we designed a study of Lake Vombsjön for an additional two years. When compared with subsequent years, 2018 was defined by an extended period of thermal stratification and hypoxia near the..., , , # Data from: Unexpected shift from cyanobacterial to dinoflagellate dominance due to a summer drought

#### Description of the data and file structure

Data in file ‘EW_Data_All’ is presented in the order it appears in the manuscript, see below for more information. Data for Table 3 falls under the license CC BY and can therefore only be found in the following repository: [https://github.com/SJean99/Plankton-LakeVombsjon-Scania/tree/main](https://github.com/SJean99/Plankton-LakeVombsjon-Scania/tree/main).

Sheets in excel file ‘EW_Data_All:
Table1: Combined surface water temperature from our own sampling and from Sydvatten
Table2: Temperature (surface and bottom), DO (bottom) and RWCS from Sydvatten
Table3: Monthly average outflow and cumulative precipitation from SMHI (available at [https://github.com/SJean99/Plankton-LakeVombsjon-Scania/tree/main](https://github.com/SJean99/Plankton-LakeVombsjon-Scania/tree/main))
Table4: Nutrient data
Table5: Chlorophyll-a (fluorometry) and phytoplan...