RadialPheno: A tool for near‐surface phenology analysis through radial layouts

Abstract

Premise Increasingly, researchers studying plant phenology are exploring novel technologies to remotely observe plant changes over time. The increasing use of phenocams to monitor leaf phenology, based on the analysis of indices extracted from sequences of daily digital vegetation images, has demanded the development of appropriate tools for data visualization and analysis. Here, we describe RadialPheno, a tool that uses radial layouts to represent time series from digital repeat photographs, and applies them to the analysis of leafing patterns and leaf exchange strategies of different vegetations. Methods and Results We developed a web tool, RadialPheno, provided with the R and Shiny environments, which uses radial visual structures to represent cyclical multidimensional temporal data associated with digital image time series. We demonstrate the application of our methods and tool for a savanna vegetation phenology in the Brazilian Cerrado. We visually represented the greenness index extracted from sequential imagery using the RadialPheno tool. Conclusions RadialPheno was successfully applied for the visualization and interpretation of individual, species, and community long‐term leafing phenology data associated with near‐surface phenological observations of Cerrado vegetation. RadialPheno was also effective for intercomparisons of ground‐based direct visual observations and camera‐derived phenology observations.

Vizplan: A Visual Analytics Platform for the Assessment of Multidimensional Indicators Over Time

“…For more details regarding successful approaches for time-oriented data visualization, the readers may refer to (Aigner et al, 2008, Aigner et al, 2011. Mariano et al (Mariano et al, 2018, Mariano et al, 2019, for example, integrated visual rhythms with radial structures to support the analysis of phenological data encoded in stack of relational tables (Mariano et al, 2018) or images (Mariano et al, 2019). The main goal was to support the analysis of temporal changes of phenological variables.…”