Geographic range velocity and its association with phylogeny and life history traits in North American woody plants.

Paul G Harnik,Paul S Manos,Hafiz Maherali,Joshua H Miller

doi:10.1002/ece3.3880

Abstract

The geographic ranges of taxa change in response to environmental conditions. Yet whether rates of range movement (biotic velocities) are phylogenetically conserved is not well known. Phylogenetic conservatism of biotic velocities could reflect similarities among related lineages in climatic tolerances and dispersal‐associated traits. We assess whether late Quaternary biotic velocities were phylogenetically conserved and whether they correlate with climatic tolerances and dispersal‐associated traits. We used phylogenetic regression and nonparametric correlation to evaluate associations between biotic velocities, dispersal‐associated traits, and climatic tolerances for 28 woody plant genera and subgenera in North America. The velocities with which woody plant taxa shifted their core geographic range limits were positively correlated from time step to time step between 16 and 7 ka. The strength of this correlation weakened after 7 ka as the pace of climate change slowed. Dispersal‐associated traits and climatic tolerances were not associated with biotic velocities. Although the biotic velocities of some genera were consistently fast and others consistently slow, biotic velocities were not phylogenetically conserved. The rapid late Quaternary range shifts of plants lacking traits that facilitate frequent long‐distance dispersal has long been noted (i.e., Reid's Paradox). Our results are consistent with this paradox and show that it remains robust when phylogenetic information is taken into account. The lack of association between biotic velocities, dispersal‐associated traits, and climatic tolerances may reflect several, nonmutually exclusive processes, including rare long‐distance dispersal, biotic interactions, and cryptic refugia. Because late Quaternary biotic velocities were decoupled from dispersal‐associated traits, trait data for genera and subgenera cannot be used to predict longer‐term (millennial‐scale) floristic responses to climate change.

Highlights

The geographic ranges of species can change rapidly
We find that the biotic velocities of individual woody plant genera were consistent through the late Quaternary, as evident by their temporal autocorrelation over the past 16 ka
Rank order differences in genus biotic velocities were correlated between adjacent time intervals, the absolute rates of range movement varied (Figures 2 and 3), and autocorrelation tended to be stronger for northern versus southern velocities. This result is similar to that observed in analyses of North American mammal genera in which late Holocene geographic range sizes were significantly correlated with late Pleistocene range sizes (Hadly et al, 2009)

Summary

| INTRODUCTION

The geographic ranges of species can change rapidly. This is evident in the recent shifts of species upslope along elevational gradients (Chen, Hill, Ohlemüller, Roy, & Thomas, 2011; Colwell, Brehm, Cardelús, Gilman, & Longino, 2008), poleward along latitudinal gradients (Breed, Stichter, & Crone, 2013), and in the geographic spread of invasive species (Sakai et al, 2001; Sax, Stachowicz, & Gaines, 2005) over decadal to centennial time scales. We found that traits which are correlated with the pace of geographic range shifts today (e.g., seed mass in Hamilton et al, 2005) and present-day range limits (e.g., cold tolerance in Lee- Yaw et al, 2016) were not associated with biotic velocities through the late Quaternary. This lack of association may reflect the nonmutually exclusive influences of rare long-d istance dispersal events, biotic interactions, and/or cryptic refugia on late Quaternary biotic velocities

| MATERIALS AND METHODS

Findings

| DISCUSSION