Dataset of a three-year litter decomposition experiment in a karst forest: litter mass loss, chemical element concentrations, and soil fauna community composition

This dataset contains raw data from a three-year litter decomposition experiment conducted in a subtropical karst forest at the Puding Karst Ecosystem Research Station, Guizhou Province, southwestern China (105°45′36″E, 26°21′37″N; 1197 m a.s.l.). The experiment aimed to quantify how initial litter chemistry, particularly calcium (Ca) content and carbon-to-nitrogen (C:N) ratio, modulates the functional contributions of soil fauna of different body sizes to decomposition. Experimental design Five litter treatments were established using the dominant plant species of the local karst forest: monospecific litters of the herb Imperata cylindrica (IC) and the broadleaf trees Platycarya longipes (PL) and Cyclobalanopsis platycarpa (CP), and two mixed-species litters (PL + CP at a 1:1 mass ratio, and IC + PL + CP at a 1:1:1 mass ratio). Litterbags with three mesh sizes (0.01 mm, 2 mm, and 4 mm) were used to selectively exclude soil fauna by body-size class, following the classical categorization of microfauna, mesofauna, and macrofauna. A total of 750 litterbags were deployed across five replicate plots and retrieved at ten sampling dates spanning 0 to 1,097 days (2 January 2020 to 3 January 2023). Data files The dataset comprises three files: litter_decomposition_data.csv (700 rows × 14 columns): Litter mass remaining (g), percent mass remaining, and concentrations of total organic carbon, total nitrogen, total phosphorus, total potassium, and total calcium (all in g kg⁻¹), plus the C:N ratio, for each litterbag sample across all sampling dates. soil_fauna_community.csv (450 rows × 51 columns): Abundance (number of individuals) of 46 soil fauna taxa extracted from each 2 mm and 4 mm mesh litterbag. A total of 37,486 individuals were recorded, with Prostigmata (31.5%), Mesostigmata (31.3%), Oribatida (11.4%), and Entomobryomorpha (10.2%) as the dominant groups. README.doc: Complete metadata documentation including experimental design, step-by-step protocols for litter chemical analyses and soil fauna extraction and identification, a full data dictionary for all variables, and a reference list of all 46 soil fauna taxa with their taxonomic resolution.