DOI: 10.5061/dryad.8w9ghx3r1
title: Data for: Multidimensional stoichiometric mismatch explains differences in detritivore biomass across three forest types

description: The ecological stoichiometry theory provides a framework to understand
 organism fitness and population dynamics based on the stoichiometric
 mismatch between organisms and their resources. Recent studies have
 revealed that different soil animals occupy distinct multidimensional
 stoichiometric niches (MSNs), which likely determine their specific
 stoichiometric mismatches and population responses facing resource
 changes. The goals of the present study are to examine how long-term
 forest plantations affect the multidimensional elemental contents of
 litter and detritivores and the population size of detritivores that
 occupy distinct MSNs. We evaluated the contents of ten elements of two
 detritivore taxa (lumbricid earthworms and julid millipedes) and their
 litter resources, quantified their MSNs and the multidimensional
 stoichiometric mismatches, and examined how such mismatch patterns
 influence the density and total biomass of detritivores across three
 forest types spanning from natural forests (oak forest) to plantations
 (pine and larch forests). Sixty-year pine plantations changed the
 multidimensional elemental contents of litter but did not influence the
 elemental contents of the two detritivore taxa. Earthworms and millipedes
 exhibited distinct patterns of MSNs and stoichiometric mismatches, but
 they both experienced severer stoichiometric mismatches in pine
 plantations than in oak forests and larch plantations. Such stoichiometric
 mismatches led to lower density and biomass of both earthworms and
 millipedes in pine plantations. In other words, under conditions of low
 litter quality and severe stoichiometric mismatches in pine plantations,
 detritivores maintained their body elemental contents but decreased their
 population biomass. Our study illustrates the success of using the
 multidimensional stoichiometric framework to understand the impact of
 forest plantations on animal population dynamics, which may serve as a
 useful tool in addressing ecosystem responses to global environmental
 changes.
description: On the Dongling mountain of Beijing city, China, we established
 five sampling plots (50 m × 50 m) in different valleys for each of three
 forest types: oak, larch, and pine, dominated by Quercus liaotungensis
 Koidz., Larix principis rupprechtii Mayr., and Pinus tabulaeformis Carr.,
 respectively. To measure the total dry biomass and density of earthworms
 and millipedes, in each plot we collected three subsamples (30 cm in
 diameter) comprising litter (L layer), organic matter (F and H layer), and
 top 10 cm soil (Ah layer).  These three subsamples were pooled into one
 aggregate sample for each plot (n = 15 in total) and taken to the
 laboratory to extract earthworms and millipedes by sieving and
 hand-picking. Then, the samples were heated for 24 h in a Tullgren
 apparatus equipped with a 40 W bulb to collect smaller earthworms and
 millipedes. Animals were freeze-dried for 72 h and
 individual body mass (dry weight) were measured using an electronic
 microbalance (MYA 5.4Y, RADWAG Wagi Elektroniczne, Poland) to the nearest
 microgram (±0.1µg). Adult individuals of earthworms and millipedes (body
 mass higher than 5 mg and 2 mg, respectively) were selected for elemental
 analysis. Specimens larger than 10 mg were ground individually to a
 homogenous powder using a bead mill homogenizer (Bead Ruptor 12, Omni
 International, USA). Approximately 2 mg powder of each
 ground sample was used to quantify C and N contents using a vario EL cube
 CHNOS Elemental Analyzer (Elementar Analysensysteme GmbH, Germany).
 Another ~2 mg powder of the ground sample was digested with nitric acid (2
 ml and 70% by weight) for quantifying the contents of Ca, Cu, K, Mg, Mn,
 Na, P, and Zn using an iCAP 6301 ICP-OES Spectrometer (Thermo Fisher,
 USA). For specimens smaller than 10 mg, we used their whole body to
 quantify C/N or the other eight elements, except for six large individuals
 of earthworms and eight large individuals of millipedes, which we cut into
 two halves prior to quantifying C/N and the other elements. From each
 plot, we further took another five leaf litter subsamples (0.5 m × 0.5 m,
 in total n = 75) for litter biomass and elemental content analysis. We
 also measured the ten elemental contents of the five litter samples from
 each plot.  For each litter sample, after freeze-dried for 72 h, we ground
 approximately 5 g leaf litters (including microbes living on them) and
 then used ~ 8 mg and ~ 50 mg powders to measure C and N and the other
 eight elements, respectively.