Biodiversity trends show an excess of both near stasis and of very large change

An analysis of trends of biodiversity metrics such as species richness or evenness or total population size, shows that across many systems, the distribution in trends is poorly fit by a normal distribution, is heavy tailed, and well-fit by a Laplace or Subbotin distribution.

The paper is in final revision at Ecology Letters in February 2026.

This repository contains all the code necessary to reproduce the anlaysis. It contains both pointers to the source data (abundance of many species through time at many locations), and also a summarized form of the data (tends in biodiversity metrics at many locations/taxa) that supports all analyses. See the readme.txt file for orientation.