DOI: 10.5061/dryad.n5h64
title: Data from: Decreasing stoichiometric resource quality drives compensatory feeding across trophic levels in tropical litter invertebrate communities

description: Living organisms are constrained by both resource quantity and quality.
 Ecological stoichiometry offers important insights into how the elemental
 composition of resources affects their consumers. If resource quality
 decreases, consumers can respond by shifting their body stoichiometry,
 avoiding low-quality resources, or up-regulating feeding rates to maintain
 the supply of required elements while excreting excess carbon (i.e.,
 compensatory feeding). We analyzed multitrophic consumer body
 stoichiometry, biomass, and feeding rates along a resource-quality
 gradient in the litter of tropical forest and rubber and oil-palm
 plantations. Specifically, we calculated macroinvertebrate feeding rates
 based on consumer metabolic demand and assimilation efficiency. Using
 linear mixed effects models, we assessed resource-quality effects on
 macroinvertebrate detritivore and predator communities. We did not detect
 shifts in consumer body stoichiometry or decreases in consumer biomass in
 response to declining resource quality, as indicated by increasing
 carbon-to-nitrogen ratios. However, across trophic levels, we found a
 strong indication of decreasing resource quality leading to increased
 consumer feeding rates through altered assimilation efficiency and
 community body size structure. Our study reveals the influence of resource
 quality on multitrophic consumer feeding rates and suggests compensatory
 feeding to be more common across consumer trophic levels than was formerly
 known.
description: Animal tissue carbon and
 nitrogen contentCarbon and nitrogen
 content as % of dry mass for 391 macro-invertebrate individuals (four
 feeding types: detritivore, herbivore, omnivore, predator) sampled on the
 core sites of the EFForTS project
 (http://www.uni-goettingen.de/en/310995.html) in the Jambi Province on
 Sumatra, Indonesia in 2012. Sites are coded as landscape-transformation
 system-replicate (two landscapes: Bukit Duabelas and Harapan; four
 transformation systems: Forest, Jungle rubber, Rubber, Oil palm).
 Sample.code is an object identifier.Jochum_animal_CN.csvLeaf-litter tissue carbon and nitrogen contentCarbon and nitrogen content as % of dry mass for 169 leaf-litter specimen sampled on the core sites of the EFForTS project (http://www.uni-goettingen.de/en/310995.html) in the Jambi Province on Sumatra, Indonesia in 2012. Sites are coded as landscape-transformation system-replicate (two landscapes: Bukit Duabelas and Harapan; four transformation systems: Forest, Jungle rubber, Rubber, Oil palm). Leaf.sample.code is an object identifier. Rubber.leaf and oilpalm.leaf identify specimens as being rubber or oil palm leaves (1) or not (0).Jochum_litter_CN.csvMacro-invertebrate community data per site and feeding typeAnimal community data for litter macro-invertebrates of four different feeding types (detritivore, herbivore, omnivore, predator) sampled on the core sites of the EFForTS project (http://www.uni-goettingen.de/en/310995.html) in the Jambi Province on Sumatra, Indonesia in 2012. Sites are coded as landscape-transformation system-replicate (two landscapes: Bukit Duabelas and Harapan; four transformation systems: Forest, Jungle rubber, Rubber, Oil palm). Dens gives the density as number of individuals m-2, div is the number of morphospecies per core site, bmass is the fresh biomass in mg m-2 and metabolic.demand is the sum of the individual metabolic rates of all individuals found per area in W m-2. For further details on the animal sampling and calculation of metabolic rates see Barnes & Jochum et al., NatCommun, 2014 (doi:10.1038/ncomms6351).Jochum_animal_community_data.csvData for main analyses and Figure 3Processed data on leaf litter, detritivore (Det) and predator (Pre) communities sampled on the core sites of the EFForTS project (http://www.uni-goettingen.de/en/310995.html) in the Jambi Province on Sumatra, Indonesia in 2012, used to perform the main analyses and plot Figure 3. Sites are coded as landscape-transformation system-replicate (two landscapes: Bukit Duabelas and Harapan; four transformation systems: Forest, Jungle rubber, Rubber, Oil palm). CN is the unitless ratio of dry-mass carbon to dry-mass nitrogen for leaf litter (single measurements weighted after relative importance of specimens in the local leaf litter) and animal tissue (averaged over measured individuals) per core site. Litter.mass gives the dry litter mass per ground area in g cm-2. Dens gives the density as number of individuals m-2, div is the number of morphospecies per core site, biomass is the fresh biomass in mg m-2 and per-unit-biomass consumer feeding rates were calculated as W mg-1. Note that data are non-logged and non-normalized.Jochum_data_for_stats_and_results_figure.csv