DOI: 10.5061/dryad.zgmsbccgn
title: No home-field advantage in litter decomposition from the desert to temperate forest

description: 1. Litter decomposition rates are determined by the interplay of climate,
 decomposer organisms and litter quality. It has been suggested that the
 decomposer community may be locally adapted to litter quality, providing a
 home-field advantage (HFA) resulting in accelerated decomposition of local
 compared to non-local litter, after accounting for decomposition
 differences due to litter quality and the functional capacity of
 microorganisms. Although widely tested in forests, this hypothesis remains
 controversial and lacks a general support of its generality across
 climates. 2. We therefore tested the HFA hypothesis for litter
 decomposition in four contrasting ecosystems along an extensive climatic
 gradient in Chile, using a translocation experiment involving litter from
 20 species. In addition to comparing mass loss, we adopted a novel way to
 disentangle decomposer effects from climate effects, based on loss rates
 of elements that are actively released from the litter by decomposers
 during its breakdown vs. elements that are simply leached by
 precipitation. We used the ratios of nitrogen and potassium losses (N/K
 loss) and phosphorus and potassium losses (P/K loss) to unravel the
 relative role of microbial breakdown (N and P loss) vs. physical leaching
 (K loss) along the climate gradient. Thus, at each site, we tested whether
 litter mass loss, N/K loss and P/K loss presented an additional loss due
 to a HFA for local compared to non-local litter. 3. Across a wide range of
 environments and 20 different litter types, our findings unequivocally
 contradicted the HFA hypothesis. We observed no significantly positive HFA
 along the gradient, however litter quality and the general ability of the
 decomposer community influenced litter decomposition much more strongly
 than origin or location of the litter. 4. Our study questions the
 applicability of the HFA for litter decomposition and calls for more
 studies that include a large range of climatic conditions to understand
 the context-dependency of HFA.
description: General description The dataset is related to the publication “No
 home-field advantage in litter decomposition from the desert to temperate
 forest”, by van den Brink et al. 2023 in Functional Ecology. The study
 aimed at testing the home-field advantage hypothesis in litter
 decomposition along a climate gradient in Chile. Thus, the dataset
 comprises litter mass loss data from a translocation experiment with 20
 litter species from four study sites (arid, semi-arid, Mediterranean and
 temperate), where each species was set to decompose in each of the study
 sites. In addition, the study used the ratios nitrogen to potassium loss
 (N/K loss) and phosphorus to potassium loss (P/K loss) to account for
 microbial breakdown (N and P loss) vs. physical leaching (K loss).
 Therefore, the dataset also contains the nutrient ratios for each mass
 loss data. The data of mass loss, N/K and P/K loss were
 used to calculate the litter ability, soil community ability and
 home-field effect according to the model presented by Keiser et al.
 (2014). The information used to run the mentioned model is also included
 in the dataset. The Excel file contains two sheets, the first
 one with the important metadata, and the second one contains the full
 data. General methods
 Five abundant and representative plant species per site were
 selected for the experiment. From those species, freshly senesced leaves
 were handpicked, while still attached to the plants during the dry season
 preceding the experiment (December 2016-January 2017). Litter was
 oven-dried at only 45°C for 48h. Five subsamples per litter species were
 separated from this initial litter and analyzed to determine initial
 element contents (C, N, P, K) per species. The initial element
 concentration was averaged at the species level. 1, 2
 or 2.5 (±0.005) g of litter of each litter species were bagged in a 2-mm
 polyester mesh of 10x10cm. Litter bags from all species were then fully
 reciprocally translocated across the four study sites (20 species * 6
 replicate plots * 4 sites) in early May 2017 (late autumn in the southern
 hemisphere). Bags were placed on top of the mineral soil or the organic
 layer (if present). The experiment was protected against animals with a
 poultry-wire mesh cage. All litterbags were retrieved after 12 months,
 placed in individual paper bags and the remaining litter was weighed after
 drying at 45°C for 48 h or until constant dry weight. For each sample, the
 percentage of litter mass loss was calculated as 100*(M0-Mt)/M0, where M0
 is the initial dry mass of a sample and Mt is the remaining dry mass after
 12 months of decomposition. The remaining litter from each litter bag was
 stored in individual paper bags and used for further elemental
 analyses. The litter was carefully cleaned and mineral
 soil particles were removed before analysis. Each litter sample was
 homogenized with a planet ball mill (Pulverisette 5, Fritsch
 Idar-Oberstein, Germany). The samples were not washed prior to the
 analysis to avoid loss of leachable elements such as K. Total C and N
 concentrations were measured by a CNS elemental analyser (Vario EL III,
 Elementar Analysensysteme GmbH, Langenselbold, Germany), and were used to
 calculate C/N mass ratios. For details regarding detection limits and
 quality controls please refer to the Supplementary Data of the
 publication. To determine the concentrations of
 potassium (K) and phosphorus (P), litter samples were dissolved by an acid
 pressure digestion system (Loftfield PDS-6, Loftfield Analytical
 Solutions, Neu Eichenberg, Germany). All vessels used were soaked in 10%
 HCl overnight and rinsed with Millipore water prior to use. Homogenized
 sample material (target weight: 0.05g) was transferred into Teflon
 pressure beakers before adding 4mL HNO3 conc. (65%, Merck KGaA, p.a. ≥
 98%). After heating for seven hours at 180°C, digestion solutions were
 filtered (MN 619 G¼ Ø185 mm, Macherey-Nagel, Düren, Germany) and diluted
 with Millipore water (Synergy UV ultrapure, Millipore) to a final volume
 of 50 ml. Digestions were analyzed by an inductively coupled plasma
 optical emission spectrometer (ICP-OES Optima 5300 DV, PerkinElmer,
 Wellesley USA) according to EN ISO 11885. Concentrations of P and K (mg
 kg-1) were calculated and corrected for recovery rates of the certified
 reference material BCR®-129 (hay powder, Institute for Reference Materials
 and Measurements). Similarly, the final element mass (mg) of a sample was
 calculated from the respective element concentration and the sample
 weight. The percentage of relative change in element
 content (K loss (%), N loss (%) and P loss (%)) for a sample was
 calculated as 100*(averaged initial element mass - final element mass) /
 averaged initial element mass. Later, the ratios N/K loss and P/K loss
 were calculated. K loss represents pure leaching effects, typically
 occurring at the very beginning of the decomposition process (Laskowski et
 al. 1995). N and P losses representing partially leaching, partially
 microbial breakdown. The ratios N/K loss and P/K loss, therefore, give an
 estimate of microbial breakdown, as they standardize N and P losses for
 leaching effects. Across sites (i.e., across the precipitation gradient),
 an increase in the ratios represents higher microbial breakdown, as the
 ratios are standardized for precipitation influence by the
 precipitation-dependent element (K). For more details
 on the methodology, please refer to the main manuscript and supplementary
 material associated to this dataset.