Tropical and temperate differences in the trophic structure and aquatic prey use of riparian predators
Data files
Sep 20, 2023 version files 646.97 KB
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README.md
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Riparian_invert_isotopes.csv
Abstract
The influence of aquatic resource-inputs on terrestrial communities is poorly understood, particularly in the tropics. We used stable isotope analysis of carbon and nitrogen to trace aquatic prey use and quantify impact on trophic structure in 240 riparian arthropod communities in tropical and temperate forests. Riparian predators consumed more aquatic prey and were more trophically diverse in the tropics than temperate regions, indicating tropical riparian communities are both more reliant on, and impacted by, aquatic resources than temperate communities. This suggests they are more vulnerable to disruption of aquatic-terrestrial linkages. Although aquatic resource use declined strongly with distance from water, we observed no correlated change in trophic structure, suggesting trophic flexibility to changing resource availability within riparian predator communities in both tropical and temperate regions. Our findings highlight the importance of aquatic resources for riparian communities, especially in the tropics, but suggest distance from water is less important than resource diversity in maintaining terrestrial trophic structure.
README: Tropical and temperate differences in the trophic structure and aquatic prey use of riparian predators
https://doi.org/10.5061/dryad.ht76hdrnb
This dataset contains taxonomic and carbon and nitrogen stable isotope data of aquatic and terrestrial riparian invertebrate communities found in streams and the surrounding terrestrial riparian zone, following a hierarchical, spatially nested design. Sampling of invertebrate communities was conducted within each stream and at five distances away from water along 150m perpendicular transects going from the stream bank into riparian forest. Sampling was replicated at 48 streams in 7 sites in two regions (tropical and temperate), for 240 total riparian communities sampled.
Description of the data and file structure
Dataset is in a .csv file. Each row represents a single sample analysed using a mass-spectrometer (not an individual animal). Dataset is unfiltered for outliers and erroneous readings (denoted in 'Notes' column). <"NA"> denotes N/A values. All additional methodological details are present in the main and supplementary components of the published paper.
Data column descriptions:
- Region - Broad global bioclimatic region (tropical or temperate)
- Site - Site name, nested within region
- Stream - Specific stream ID, nested within site
- Distance m - Distance on transect in metres from water (1, 10, 30, 60, 150) where invertebrates sampled. 'aq' denotes aquatic sample
- Order - Taxonomic order
- Family - Taxonomic family
- Genus - Taxonomic genus
- LTU - Lowest taxonomic unit (morphospecies)
- Source - Broad functional grouping for division into isotopic sources in mixing models
- No.indv. - Number of individuals in the single isotope sample (occasionally, multiple individuals were pooled to comprise a large enough sample for accurate analysis using mass spectrometry)
- Weight/vol - Final mass (mg) of material in sample ran through mass spectrometer
- N sam - Mass of N (ug) in isotoped material
- d15N - the ratio of 15N to 14N relative to a standard (air), expressed in standard δ notation (delta, denoted by 'd') in parts per thousand (‰).
- C sam - Mass of C (ug) in isotoped material
- d13C - the ratio of 13C to 12C relative to a standard (PeeDee Belemnite), expressed in standard δ notation (delta, denoted by 'd') in parts per thousand (‰).
- C:N - ratio of the mass of C to N in isotoped material
- Beam area N - output from the mass spec for checking for technical issues
- Beam area C - output from the mass spec for checking for technical issues
- Notes - Specifies isotopic errors, outliers or corrections (Cananéia samples are corrected for Ethanol preservation using a mass-balance approach. Details can be found in the supplementary material of the manuscript).
Methods
Further methodological details on data collection can be found within the published paper and its supplementary material.