RAMAS® Community

A free web app for characterizing temporal change in ecological communities.


This web application implements the methods for measuring temporal change in communities described in Spencer (2015)(1). The paper introduces a measure of change in relative abundances (the “shape” of a community) that complements measures of mean proportional change in abundance (the “size” of a community) such as the Living Planet Index (2).

The application also implements a wide range of other measures of change in relative abundance, reviewed in Spencer (2015)(1), and offers interactive visualization of results. Uncertainty in abundance data can be handled through interval arithmetic, approximate confidence intervals based on simple sampling models, or through user-supplied Monte Carlo estimates.

An R package implementation is also available on GitHub



  1. Spencer, M. (2015). Size change, shape change, and the growth space of a community. Journal of Theoretical Biology 369:23-41. http://dx.doi.org/10.1016/j.jtbi.2015.01.002

  2. Loh, J., Green, R. E., Ricketts, T., Lamoreux, J., Jenkins, M., Kapos, V., Randers, J., 2005. The Living Planet Index: using species population time series to track trends in biodiversity. Philosophical Transactions of the Royal Society B 360, 289–295.