barrel: An R Package for Reproducible and Tidy Ordination Plotting in Ecology

Aim Ordination methods are widely used in vegetation science to summarize multivariate patterns in species composition and environmental gradients. Although statistical tools for fitting ordination models are well developed in R, tools for producing tidy, reproducible, and extensible way remain fragmented. We present barrel , an R package that provides a modular grammar for ecological ordination plotting based on the ggplot2 ecosystem. Methods barrel implements a consistent interface for adding ordination elements such as confidence ellipses, group centroids, and environmental vectors to ordination diagrams. The package supports both unconstrained and constrained ordination methods and includes automatic axis labeling, significance‐based filtering, and multiple geometric representations. The package also supports both classical and robust estimation of group ellipses for graphical summaries in the presence of ecological outliers. Results barrel enables the rapid construction of reproducible ordination graphics through two complementary interfaces: autoplot() for automated figure generation and stat_barrel_*() layers for advanced customization within ggplot2 . The package facilitates exploratory analysis, teaching, and the production of publication‐quality ordination figures across a wide range of ecological applications. Conclusions barrel provides a reproducible and extensible framework for ordination plotting in R that unifies common ecological visualization workflows within a tidy and customizable grammar‐of‐graphics approach.