funspace: An R package to build, analyse and plot functional trait spaces

Abstract

Aim: Functional trait space analyses are pivotal to describe and compare organ-isms' functional diversity across the tree of life. Yet, there is no single applicationthat streamlines the many sometimes-troublesome steps needed to build and analysefunctional trait spaces.Innovation: To fill this gap, we propose funspace, an R package to easily handle bi-variate and multivariate functional trait space analyses. The six functions that consti-tute the package can be grouped in three modules: ‘Building and exploring’, ‘Mapping’and ‘Plotting’. The building and exploring module defines the main features of a func-tional trait space (e.g. functional diversity metrics) by leveraging kernel density-basedmethods. The mapping module uses general additive models to map how a targetvariable distributes within a trait space. The plotting module provides many optionsfor creating flexible and publication-ready figures representing the outputs obtainedfrom previous modules. We provide a worked example to demonstrate a completefunspace workflow.Main Conclusions: funspace will provide researchers working with functional traitsacross the tree of life with a new tool to easily explore: (i) the main features of anyfunctional trait space, (ii) the relationship between a functional trait space and anyother biological or non-biological factor that might contribute to shaping species'functional diversity.