A non-equilibrium species distribution model reveals unprecedented depth of time lag responses to past environmental change trajectories

Previous studies have demonstrated legacy effects of current species
distributions to past environmental conditions, but the temporal extent of
such time lag dynamics remains unknown. Here, we have developed a
non-equilibrium SDM approach quantifying the temporal extent that must be
taken into account to capture 95 % of the effect that a given time series
of past environmental conditions has on the current distribution of a
species. We applied this approach to the distribution of 92 European
forest birds in response to past trajectories of change in forest cover
and climate. We found that non-equilibrium SDMs outperformed traditional
SDMs for 95% of the species. Non-equilibrium SDMs suggest unprecedented
long-lasting effects of past global changes (average time lag extent
ranged from 9 years to 231 years). This framework can help to relax the
equilibrium hypothesis of traditional SDMs and to improve future
predictions of biodiversity redistribution in response to global changes.