DOI: 10.5061/dryad.pvmcvdp0d
title: Contrasting effects of deadwood and gaps on the trophic structure of forest soil microarthropods

description: Understanding the mechanisms driving forest biodiversity is challenging,
 especially in soil. Trophic niche is the most important perspective to
 understand how biodiversity changes with disturbances. Deadwood input and
 gap formation are major disturbances resulting from tree mortality. Both
 alter the ecological niches of forest organisms, yet their individual and
 interactive effects on soil animals remain unclear. Trophic diversity,
 i.e., the area of trophic niches occupied by organisms, links to the
 resource processing within food webs and, consequently, to ecosystem
 functions. Changes in the trophic diversity of Collembola communities may
 result from both changes in species composition and from trophic shifts of
 individual species. To investigate how the trophic structure of soil fauna
 responds to forest disturbances, we examined trophic niches of Collembola
 across three regions in Germany, as influenced by deadwood addition and
 gap formation using stable isotope analysis (13C, 15N). Changes in the
 trophic structure of Collembola associated with deadwood addition and gap
 formation were distinct and independent. The deadwood addition resulted in
 higher trophic level (Δ15N) and greater trophic diversity of Collembola
 communities. These shifts were likely driven by increased habitat
 heterogeneity, resulting in higher trophic differentiation (rather than
 higher species richness) of Collembola communities. The results highlight
 the importance of habitat structure in driving soil animal functional
 diversity. By contrast, gap formation promoted the growth of understory
 plants, leading to increased use of plant-derived resources (lower Δ13C)
 by Collembola. Further, gap formation reduced the trophic diversity of
 euedaphic (soil-dwelling) Collembola, pointing to trophic homogenisation,
 likely driven by increased use of root-derived resources from understory
 plants, and this was also accompanied by higher biomass of euedaphic
 Collembola in forest gaps. Overall, our findings highlight that deadwood
 addition and gap formation affect the trophic structure of detritivore
 communities in an independent way, with deadwood enhancing habitat
 heterogeneity and trophic differentiation, while gap formation results in
 trophic homogenisation and increased resource supply to euedaphic
 Collembola. Thereby, deadwood addition and gap formation complement each
 other in affecting the trophic structure of detritivore soil animals and
 thereby their functioning.
description: # Contrasting effects of deadwood and gaps on the trophic structure of
 forest soil microarthropods Dataset DOI:
 [10.5061/dryad.pvmcvdp0d](https://doi.org/10.5061/dryad.pvmcvdp0d) ##
 General information Authors:Yan Zhang, André Junggebauer, Melanie M.
 Pollierer, Stefan Scheu, Zheng Zhou **Contact information:** Date created
 by: Yan Zhang Affiliations: Johann Friedrich Blumenbach Institute of
 Zoology and Anthropology, University of Goettingen Date created at:
 2025/01/07 Dates of data collection: April-October 2024 Email:
 [yzhangd@uni-goettingen.de](mailto:yzhangd@uni-goettingen.de) location:
 Germany **Methodology used** Trophic niches are indicated by 13C and 15N,
 and trophic diversity is indicated by the area of 13C and 15N, using bulk
 stable isotopes. # Description of the data and file structure ### Files
 and variables 1.data_for_r_script_isotope_Collembola.csv: stable isotope
 data of Collembola in each site, each treatment. The data has been cleaned
 by filtering the N amount &lt; 0.18, since a smaller N amount of organisms
 caused unstable 15N values due to technical limitations.
 2.data_for_r_script_species_traits.csv: The information of Collembola in
 taxonomic and traits （life forms and reproduction）
 3.data_for_r_script_community_Collembola.csv: complements information of
 the Collembola community collected during identification.
 4.data_for_r_script_environmental_factors.csv: the moisture and microbial
 biomass C were used for piecewise structural equation models. #### File:
 1.data_for_r_script_isotope_Collembola.csv **Description:**  #####
 Variables * test_ID: a number in the isotope measurement * Sample: sample
 ID * Region: Region name (AEW/HEW/SEW) * Layer: sample layer (litter/0-5
 soil) * Plot: Plot ID (with a total of 29 plots) * Forest.type: Name of
 forest type in each plot * Treatment: Experiment treatment (Control, gap,
 deadwood, gap+deadwood) * Species: Species name * Abundance: number of
 individuals * weight: weight of Collembola species (mg) * N.amount:
 nitrogen amount (ug) * C.amount: carbon amount (ug) * ratioC.N: C/N ratio
 * ratioC.N.Cblank.corrected: standard sample correction * litter_15N:
 litter 15N * litter_13C: litter 13C * D15N: calibrated 15N of Collembola
 (by litter) * D13C: calibrated 13C  of Collembola (by litter) #### File:
 2.data_for_r_script_species_traits.csv **Description:** Collembola traits,
 i.e., life forms and reproduction mode for each species ##### Variables *
 verbatimScientificName: ScientificName * Reproduction: trait
 (sexual/parthenogenetic) * life_forms: trait
 (epedaphic/hemiedaphic/euedaphic) * scientificName: scientific name *
 order: order name * family: family name * genus: genus * species: species
 name * canonicalName: canonicalName #### File:
 4.data_for_r_script_environmental_factors.csv
 **Description:** environmental factors  ##### Variables * PlotID: plotID *
 Region: three regions in total * Treatment: experimental treatment *
 Layer: soil(0-5cm)/litter * Cmic: microbial biomass C (mg kg ^-1^ soil) *
 water_content: soil moisture (%) #### File:
 3.data_for_r_script_community_Collembola.csv **Description:** community
 abundance and richness of Collembola in FOX ##### Variables * Sample:
 Sample ID * Region: Region(AEW/HEW/SEW) * Layer: litter/soil (0-5cm) *
 Plot: PlotID (with a total of 29 plots) * Forest type: The type of Forest
 * Treatment: The treatments of the experiment (Control, Gap, Deadwood, and
 Gap+Deadwood) * Species: full species name * Abundance: Abundance (number
 of individuals) * species: species name ## Code/software File: r_script.R
 Description: The R script for the analysis of the current study Software:
 R version 4.4.0 ## Access information This dataset was not derived from
 other sources.