Analysis of relative abundances on environmental gradients
- Published
- Accepted
- Subject Areas
- Ecology, Marine Biology, Mathematical Biology
- Keywords
- compositional data analysis, fouling communities, environmental gradients, linear algebra
- Copyright
- © 2018 Chong et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2018. Analysis of relative abundances on environmental gradients. PeerJ Preprints 6:e26908v1 https://doi.org/10.7287/peerj.preprints.26908v1
Abstract
Ecologists often analyze relative abundances, which are compositions (sets of non-negative numbers with a fixed sum). However, they have made surprisingly little use of recent advances in the field of compositional data analysis. Compositions form a vector space in which addition and scalar multiplication are replaced by operations known as perturbation and powering. This algebraic structure makes it easy to understand how relative abundances change along environmental gradients. We illustrate this with an analysis of changes in hard-substrate marine communities along a depth gradient. We show how the algebra of compositions can be used to understand patterns in dissimilarity. We use the calculus of simplex-valued functions to estimate rates of change, and to summarize the structure of the community over a vertical slice. We discuss the benefits of the compositional approach in the interpretation and visualization of relative abundance data.
Author Comment
This is a submission to PeerJ for review.