DOI: 10.5061/dryad.mkkwh714t
title: Data for the article: Trophic positions of soil microarthropods in forests increase with elevation, but energy channels remain unchanged

description: Mountain forests are at risk as the consequences of climate change will
 likely lead to altered tree species boundaries. Characterizing food webs
 along elevation gradients in primary forests may help to predict the
 potential consequences of such changes, for example with regard to the
 decomposition of dead organic matter. Here, for the first time, we studied
 trophic variations in two species‐rich microarthropod taxa, Collembola and
 Oribatida, along an elevation gradient of primary forest at Changbai
 Mountain, China. Samples were taken at seven elevations of 150‐m
 elevational difference between 800 and 1700 m. At each elevation,
 Collembola and Oribatida were extracted from litter samples of eight
 subplots. We applied three state‐of‐the‐art methods to elucidate trophic
 positions and basal resource use at community level: Bulk stable isotope
 analysis of nitrogen (Δ15Nbulk) and carbon (Δ13Cbulk), compound‐specific
 stable isotope analysis of amino acids (CSIA‐AA), and dietary routing of
 neutral lipid fatty acids (NLFAs). Trophic positions calculated using
 Δ15Nbulk and CSIA‐AA (TPCSIA) in both taxa increased similarly with
 elevation by about half and one third of a trophic position, respectively.
 Stable isotope mixing models and linear discriminant analysis
 bootstrapping using δ13C of essential amino acids indicated fungi as the
 most important resource at all elevations for both taxa. Also, proportions
 of marker NLFAs changed little across elevations in both taxa; overall
 high proportions of linoleic acid indicated high fungal contributions, but
 in Collembola the contribution of bacterial markers was generally higher
 than in Oribatida. Δ13Cbulk did not respond linearly to the elevation
 gradient; however, changes in elevation differed between Collembola and
 Oribatida. A strong linear relationship between δ15N of phenylalanine and
 δ15N of litter indicated litter as the basis of energy channels in both
 taxa. Overall, food web functioning likely changes with changing forest
 types along elevation gradients, with microarthropods switching from
 feeding closer to the base of the food web at lower elevations to feeding
 at higher trophic levels at higher elevations, potentially compromising
 their role in litter decomposition and nutrient cycling.
description: # Data for the article: Trophic positions of soil microarthropods in
 forests increase with elevation, but energy channels remain unchanged
 Dataset Contributors:
 Creators: Johannes Lux, Zhijing Xie, Xin Sun, Donghui Wu, Melanie M.
 Pollierer, Stefan Scheu Date of issue: 2023-04-18 Corresponding author:
 Name: Johannes Lux E-mail: johannesmichel.lux@uni-goettingen.de Address:
 Untere Karspüle 2, Tierökologie, 37073 Göttingen, Lower Saxony, Germany
 Funding: This work was supported by the National Natural Science
 Foundation of China (NSFC; No. 31861133006-42071059) and the German
 Science Foundation (DFG; SCHE/376/42-1) in the framework of the
 Sino-German agreement between the DFG and the NSFC. Dataset Metadata: Date
 of data collection: 09-2019 Sampling Location: The northern slope of
 Changbai Mountain (42°8’25.4004”N, 128°7’36.2352”E), Jilin Province, China
 Labratory work was conducted in the J.-F. Blumenbach Institute of Zoology
 and Anthropology, University of Göttingen, Göttingen, Germany For details
 of sample handling and measurement please see the respective publication.
 ## Data overview Filelist: "amino_acid_13C_consumer.CSV"
 "bulk_SI_C_N.CSV" "rel_abundance_NLFA.CSV"
 "TP_Glu_Phe.CSV" Filename:
 "amino_acid_13C_consumer.CSV" Variables: elevation: sampled
 elevation subplot: replicate (per elevation) taxon: measured Taxon (C =
 Collembola, O = Oribatida) Amino Acid: names of measured amino acids d13C
 [‰]: delta 13C values of the respective measurement Details: Contains the
 final delta 13C values of Amino Acids: Alanine, Asparagine, Glutamic Acid,
 Glycine, Histidine, Isoleucine, Leucine, Lysine, Methionine, Nor-Leucine
 (internal standard), Phenylalanine, Proline, Serine, Threonine and
 Tyrosine. delta 13C was calculated as (13C/12C of the sample - 13C/12C of
 of standard)/(13C/12C of standard). "Vienna Pee Dee belemnite"
 was used as standard. Unit is ‰. NA indicates that delta 13C of the
 respective amino acid could not be measured because the amino acid was
 absent in the sample. For details of measurement please see the respective
 publication. ### Description of the Data and file structure: This dataset
 represent the backbone of fingerprinting approaches in the respective
 publication. This dataset is of interest for following up studies at
 Changbai Mountain China. Especially, if interested in the elevational
 gradient. Data is given per elevation, subplot and taxon (Collembola and
 Oribatida). Filename: "bulk_SI_C_N.CSV" Variables: elevation:
 sampled elevation subplot: replicate (per elevation) taxon: measured Taxon
 (C = Collembola, O = Oribatida) d15N_consumer: delta 15N measurements of
 Collembola and Oribatida d13C_consumer: delta 13C measurements of
 Collembola and Oribatida d15N_litter: delta 15N measurements of litter
 material d13C_litter: delta 13C measurements of litter material
 D15N_baselined: litter calibrated delta 15N of consumer D13C_baselined:
 litter calibrated delta 13C of consumer Details: Contains delta 13C and
 delta 15N values of Collembola and Oribatida bulk measurements, delta 13C
 and delta 15N measurements of intact litter material as well as the
 normalised values expressed as capital Delta 13C and Delta 15N. delta
 values were calculated as (R sample - R standard)/(R standard). With R
 being the 15N/14N or 13C/12C ratio in the sample and standard.
 "Vienna Pee Dee belemnite" was used as standard for 13C and
 atmospheric Nitrogen for 15N measurements. The calculated delta values
 were calibrated using the delta values of litter from the respective
 elevation and subplot as baseline and are expressed as capital Delta. Unit
 is ‰. For details of measurement please see the respective publication.
 ### Description of the Data and file structure: This dataset represent the
 backbone of trophic analyses based on bulk stable isotopes in the
 respective publication. This dataset is of interest for following up
 studies at Changbai Mountain China. Especially, if interested in the
 elevational gradient. Data is given per elevation, subplot and taxon
 (Collembola and Oribatida). Filename: "rel_abundance_NLFA.CSV"
 Variables: elevation: sampled elevation subplot: replicate (per elevation)
 taxon: measured Taxon (C = Collembola, O = Oribatida) NLFA: name of the
 measured neutral lipid fatty acid rel_abundance: relative abundances of
 NLFA within sample ### Details: Contains relative abundances of NLFA with
 relative abundances &gt;1% in at least one of the measurements for
 Collembola. For further details of measurement please see the respective
 publication. ### Description of the Data and file structure This dataset
 represent the backbone of trophic analyses based on neutal lipid fatty
 acids in the respective publication. This dataset is of interest for
 following up studies at Changbai Mountain China. Especially, if interested
 in the elevational gradient. Data is given per elevation, subplot and
 taxon (Collembola and Oribatida). Filename: "TP_Glu_Phe.CSV"
 Variables: elevation: sampled elevation subplot: replicate (per elevation)
 taxon: measured Taxon (C = Collembola, O = Oribatida) TP: Trophic position
 of consumer ### Details: Contains trophic positions of Collembola and
 Oribatida calculated from delta 15N values of glutamic acid and
 phenylalanine. For details of calculation please see the respective
 publication. ### Description of the Data and file structure: This dataset
 represents the Trophic position calculated from amino acids given in the
 respective publication. This dataset is of interest for following up
 studies at Changbai Mountain China. Especially, if interested in the
 elevational gradient. Data is given per elevation, subplot and taxon
 (Collembola and Oribatida).