This dataset contains data from an investigation into the drivers on the spatial distribution of dissolved organic matter in alpine lakes in the Tibetan Plateau described in the paper: “Du Y., Chen F., Xiao K., Song C., He H., Zhang Q., Zhou Y., Jang K.-S., Zhang Y., Xing P., Liu Z., Zhang Y. and Lu Y. 2021. Water Residence Time and Temperature Drive the Dynamics of Dissolved Organic Matter in Alpine Lakes in the Tibetan Plateau, Global Biogeochemical Cycles 35(11), e2020GB006908”. 

The primary objectives of the study were to: (i) evaluate the spatial variability of the amount, source, and composition of DOM from alpine lakes on the Tibetan Plateau, and (ii) determine the primary environmental controls and mechanisms responsible for the spatial variability.

At first, we collected 35 water samples from 25 lakes distributed in the northwestern (33.1–33.6 °N, 78.9–80.4°E), central (30.5–31.9°N, 88.3–89.4°E) and southeastern (28.6–29.1 °N, 90.4–90.8°E) regions of the plateau. We characterized water chemistry and DOM composition in these lakes by measuring dissolved organic carbon (DOC) and DOM optical properties (i.e., absorbance and fluorescence spectroscopy). DOM compositions of three lakes of different water residence times (WRTs) were further analyzed using ultrahigh-resolution molecular techniques (i.e., electrospray ionization-assisted Fourier transform-ion cyclotron resonance mass spectrometry, ESI FT-ICR MS).

Secondly, we collected the indices of climatic characteristics (i.e., mean annual temperature, mean annual precipitation, and mean annual irradiation period) and lake hydrology (i.e., catchment area, lake area, mean depth and water residence time) of the sampling lakes.

Thirdly, we performed statistical analysis to determine the primary environmental control and predictors of the spatial variability in lacustrine DOM on the Tibetan Plateau. The statistical analyses included non-parametric Kruskal-Wallis with Dunn post hoc test, spearman's bivariate correlations, redundancy analysis, and linear regression models.

Main results of this work are that (1) DOM in Tibetan alpine lakes is mediated more by in-lake production and transformations than by catchment inputs; (2) water residence time (WRT) of lakes and mean annual temperature (MAT) accounted for 30–59% of the spatial variance of the abundance of chromophoric DOM (CDOM) and fluorescent DOM (FDOM); (3) Alpine lakes on the Tibetan Plateau would play a more active and prominent role in regional and global carbon cycles in the face of climate change.

The dataset was collected during an investigation on the drivers of Dissolved Organic Matter in Alpine lakes in the Tibetan Plateau at the Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences and Department of Geological Sciences, The University of Alabama.

The data have been analyzed using a series of statistical tests (including non-parametric Kruskal-Wallis with Dunn post hoc test, spearman's bivariate correlations, redundancy analysis, and linear regression models) to produce a manuscript accepted for publication in Global Biogeochemical Cycles.

The readme file contains an explanation of each of the variables in the dataset, the associated measurement units, and -if it concerns a derived variable (displayed in grey) - the way it was calculated from the primary data (displayed in black). #NA = values not available. Information on how the measurements were done can be found in the associated manuscript referenced above.