Original data of diatom communities in two alpine lakes of eastern China

This study explored ecological responses of Erye and Sanye lakes to climate change and atmospheric deposition based on multi-proxy sedimentary records in the Taibai Mountain (eastern China). Diatom communities of the two study lakes shifted from large-sized benthic taxa to small fragilariod species after the mid-20th century, synchronous with an increase in diatom production and a decrease in mean length of diatom valves. Changes in diatom communities were significantly correlated with nitrogen deposition in both lakes and climate warming in the upstream lake. 

Methods
Diatom samples were treated using 10% HCl and 30% H2O2 according to standard procedures. Taxonomy was mainly based on Krammer and Lange‐Bertalot (1986-1991) using an Olympus BX53 microscope with an oil immersion objective at 1000. A minimum of 300 valves were counted in each sample. Diatom concentrations were calculated by counting a known area on a pipetted strewn slide, made from a 0.5 mL aliquot from a 13 mL ‘well-mixed’ suspension of ~ 0.5 - 1 g dry sediments. Meanwhile, length of each identified valve was measured using cellSens software installed in the Olympus microscope.