Title: Past and ongoing shifts in Joshua tree distribution support future modeled range contraction
Author: Cole, Kenneth L.; Ironside, Kirsten; Eischeid, Jon; Garfin, Gregg; Duffy, Phillip B.; Toney, Chris
Source: Ecological Applications. 21(1): 137-149.
Publication Series: Miscellaneous Publication
Description: The future distribution of the Joshua tree (Yucca brevifolia) is projected by combining a geostatistical analysis of 20th-century climates over its current range, future modeled climates, and paleoecological data showing its response to a past similar climate change. As climate rapidly warmed ~11 700 years ago, the range of Joshua tree contracted, leaving only the populations near what had been its northernmost limit. Its ability to spread northward into new suitable habitats after this time may have been inhibited by the somewhat earlier extinction of megafaunal dispersers, especially the Shasta ground sloth. We applied a model of climate suitability for Joshua tree, developed from its 20th-century range and climates, to future climates modeled through a set of six individual general circulation models (GCM) and one suite of 22 models for the late 21st century. All distribution data, observed climate data, and future GCM results were scaled to spatial grids of ~1 km and ~4 km in order to facilitate application within this topographically complex region. All of the models project the future elimination of Joshua tree throughout most of the southern portions of its current range. Although estimates of future monthly precipitation differ between the models, these changes are outweighed by large increases in temperature common to all the models. Only a few populations within the current range are predicted to be sustainable. Several models project significant potential future expansion into new areas beyond the current range, but the species' historical and current rates of dispersal would seem to prevent natural expansion into these new areas. Several areas are predicted to be potential sites for relocation/assisted migration. This project demonstrates how information from paleoecology and modern ecology can be integrated in order to understand ongoing processes and future distributions.
Keywords: climate change, climate effects modeling, extinct seed vectors, Joshua tree, Mohave Desert, plant migration, Yucca brevifolia
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
- You may send email to email@example.com to request a hard copy of this publication. (Please specify exactly which publication you are requesting and your mailing address.)
XML: View XML
Cole, Kenneth L.; Ironside, Kirsten; Eischeid, Jon; Garfin, Gregg; Duffy, Phillip B.; Toney, Chris. 2011. Past and ongoing shifts in Joshua tree distribution support future modeled range contraction. Ecological Applications. 21(1): 137-149.
Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility