DOI: 10.5061/dryad.t1g1jwt9g
title: Diatom cell-size composition as a novel tool for quantitative estimates of water table in peatlands

description: Diatom cell-size composition is an indicator of aquatic environmental
 changes, but has been rarely investigated, especially in semi-terrestrial
 peatlands. In this study, both taxonomic composition and cell-size
 composition of diatoms were analyzed in 41 samples from two montane
 peatlands, northeastern China. Redundancy analyses revealed that diatom
 taxonomic composition was significantly related to the depth to the water
 table (DWT) and Ca2+, while cell-size composition was significantly
 associated with DWT and Si. DWT was the most important factor and its sole
 effect explained 26.2% and 17.9% of the total variance in taxonomic
 composition and cell-size composition, respectively. Accordingly,
 diatom-based water-table transfer functions were developed based on
 taxonomic composition and cell-size composition, respectively. The maximum
 likelihood (ML) model based on diatom taxonomic composition had the best
 performance, with the correlation coefficient value (R2) of 0.78 and the
 root mean squared error of prediction (RMSEP) of 6.66 cm. The ML model
 based on cell-size composition had similar performance, with the R2 of
 0.78 and the RMSEP of 6.87cm, suggesting that diatom cell-size composition
 can be a new quantitative means to track past water-table changes.
description: For diatom taxonomic composition, a minimum of 300 diatom valves
 were counted from each sample. Data of diatom taxonomic composition and
 environmental variables are sourced from our previous study. In this
 study, lengths of more than 300 diatom valves were measured in each sample
 using an Olympus BX53 microscope with 100 Plan N equipped with an Olympus
 DP27 digital camera and the cellSens software. The precision of the
 measurement is 0.1 μm. In order to establish diatom cell-size composition,
 all diatom valves are grouped in eighteen size classes at 2-μm intervals
 (i.e., 7-9 μm, 9-11 μm, 11-13 μm, etc). Large-sized diatoms with their
 valve lengths greater than 41 μm are rare and hence classified into one
 group. The species dataset comprises 32 main species (taxa with an
 abundance of at least 1% in at least one sample).
description: # **Diatom cell-size composition as a novel tool for quantitative
 estimates of water table in peatlands**
 [https://doi.org/10.5061/dryad.t1g1jwt9g](https://doi.org/10.5061/dryad.t1g1jwt9g) **Diatom cell-size composition as a novel tool for quantitative estimates of water table in peatlands** Both taxonomic composition and cell-size composition of diatoms were analyzed in 41 surface samples from two montane peatlands, northeastern China. ## Description of the data and file structure For diatom taxonomic composition, a minimum of 300 diatom valves were counted from each sample. Data of diatom taxonomic composition and environmental variables are sourced from our previous study. In this study, lengths of more than 300 diatom valves were measured in each sample using an Olympus BX53 microscope with 100 Plan N equipped with an Olympus DP27 digital camera and the cellSens software. The precision of the measurement is 0.1 μm. In order to establish diatom cell-size composition, all diatom valves are grouped in eighteen size classes at 2-μm intervals (i.e., 7-9 μm, 9-11 μm, 11-13 μm, etc). Large-sized diatoms with their valve lengths greater than 41 μm are rare and hence classified into one group. The species dataset comprises 32 main species (taxa with an abundance of at least 1% in at least one sample). Table S1 Diatom taxonomic composition in Sphagnum samples. The first column represents sample code. The second to thirty-third columns represent diatom species with the maximum abundance &gt;1% in at least one sample. The last column represents depth to the water table (DWT). Table S2 Diatom cell-size composition in Sphagnum samples. The first column represents sample code. The second to nineteen columns represent eighteen cell-size classes. The last column represents depth to the water table (DWT).