Importance of spatio-temporal connectivity to maintain species experiencing range shifts

Climate change can affect the habitat resources available to species by
changing habitat quantity, suitability and spatial configuration, which
largely determine population persistence in the landscape. In this
context, dispersal is a central process for species to track their niche.
Assessments of the amount of reachable habitat (ARH) using static
snap-shots do not account, however, for the temporal overlap of habitat
patches that may enhance stepping-stone effects. Here, we quantified the
impacts of climate change on the ARH using a spatio-temporal connectivity
model. We first explored the importance of spatio-temporal connectivity
relative to purely spatial connectivity in a changing climate by
generating virtual species distributions and analyzed the relative effects
of changes in habitat quantity, suitability and configuration. Then, we
studied the importance of spatio-temporal connectivity in three vertebrate
species with divergent responses to climate change in North America (grey
wolf, Canadian lynx and white-tailed deer). We found that the
spatio-temporal connectivity could enhance the stepping-stone effect for
species predicted to experience range contractions, and the relative
importance of the spatio-temporal connectivity increased with the
reduction in habitat quantity and suitability. Conversely, for species
that are likely to expand their ranges, spatio-temporal connectivity had
no additional contribution to improve the ARH. We also found that changes
in habitat amount (quantity and suitability) were more influential than
changes in habitat configuration in determining the relative importance of
spatio-temporal connectivity. We conclude that spatio-temporal
connectivity may provide less biased and more realistic estimates of
habitat connectivity than purely spatial connectivity.