DOI: 10.5061/dryad.v41ns1s4b
title: Data from: Interactive effects of soil moisture, air temperature and litter nutrient diversity on soil microbial communities and Folsomia candida population

description: Soil organisms play a key role in carbon and nutrient cycling in forest
 ecosystems. While soil organisms are strongly influenced by litter
 chemistry and are highly sensitive to abiotic conditions, little is known
 about how the interactive effects of these two factors. To address this
 gap in knowledge, we conducted a 10-week microcosm experiment in which we
 simulated the effects of climate change on soil ecology. More
 specifically, we studied relationships among litter nutrient
 concentration, microbial biomass, Collembola demographic parameters, and
 litter decomposition, exploring the potential impacts of increasing air
 temperature and decreasing soil moisture. To develop a gradient of
 nutrient concentrations, we created six tree litter mixtures with
 materials gathered from Quercus pubescens and its companion species. In
 contrast to microbes, we observed that Collembola abundance and litter
 decomposition were interactively affected by soil moisture and air
 temperature: the negative effect of increasing air temperature on
 Collembola abundance was amplified by reduced soil moisture, whereas the
 positive effect of increasing air temperature on litter decomposition
 disappeared under reduced soil moisture conditions. In contrast to fungi,
 the response of bacterial biomass and Collembola abundance to litter
 nutrient concentration was dependent on abiotic conditions. More
 specifically, the relationships between nutrients, especially calcium and
 magnesium, and bacterial biomass and Collembola abundance were less robust
 or disappeared under drier or warmer conditions. In conclusion, our
 findings underscore that ongoing climate change could affect soil
 organisms directly as well as indirectly, by altering their responses to
 litter nutrient concentrations. In addition, we found that nutrient-rich
 habitats might be more affected than nutrient-poor habitats by altered
 climatic conditions.
description: # Interactive effects of soil moisture, air temperature and litter
 nutrient diversity on soil microbial communities and *Folsomia candida*
 population
 [https://doi.org/10.5061/dryad.v41ns1s4b](https://doi.org/10.5061/dryad.v41ns1s4b) ## Experimental setup To explore how litter quality influenced soil organisms, we generated a gradient of nutrient concentrations by creating litter mixtures in which *Q. pubescens* was paired with one of six woody companion species; the control litter paired *Q. pubescens* with itself. To simulate expected conditions under climate change in temperate and Mediterranean ecosystems, we conducted a laboratory experiment to test the effects of increased air temperature and decreased soil moisture. We used standard rearing conditions for *F. candida* as our reference abiotic conditions (air temperature: 20°C and soil moisture: 60% of natural water holding capacity [WHC]). We then established three other sets of treatment conditions: a 5°C increase in air temperature (25°C) combined with standard soil moisture (60% WHC); a 50% decrease in soil moisture (30% WHC) combined with standard temperature (20°C); and a 5°C increase in air temperature combined with a 50% decrease in soil moisture (25°C and 30% WHC). We examined the effects of these four sets of conditions on litter microorganisms, *F. candida*, and litter mass loss. Each set of conditions was replicated 12 times, yielding 336 microcosms in total (7 litter types × 2 temperatures × 2 soil moisture levels × 12 replicates).  The 12 replicates were organised in 4 blocks of repetition, with 3 replicates per block. Each block was spaced 3 days apart. ## Description of the data and file structure The dataset includes the microbial biomasses (Gram-positive bacteria, Gram-negative bacteria, total bacteria, Actinobacteria, AM fungi, fungi), the Collembola individual biomass and abundance, and the *Quercus pubescens* litter mass loss measured in the 336 microcosms at the end of the experiment. Microbial biomasses are expressed as µg per g of litter, *F. candida* biomass as µg, *F. candida* abundance as individual number per microcosm, and litter mass loss as percentage. NA data correspond to missing values.