Featured Research

from universities, journals, and other organizations

Uncertain future for Joshua trees in US Southwest projected with climate change

Date:
March 25, 2011
Source:
United States Geological Survey
Summary:
Temperature increases resulting from climate change in the US Southwest will likely eliminate Joshua trees from 90 percent of their current range in 60 to 90 years, according to a new study.

Joshua Trees in Inyo Mountains above Eureka Valley, CA: Scattered mature Joshua trees in this northernmost stand of Joshua trees are surrounded by abundant seedlings and saplings. Recent climates, and General Circulation Model results of future climates, portray this area as being suitable for the survival and expansion of Joshua trees.
Credit: Ken Cole, USGS

Temperature increases resulting from climate change in the Southwest will likely eliminate Joshua trees from 90 percent of their current range in 60 to 90 years, according to a new study led by U.S. Geological Survey ecologist Ken Cole.

The research team used models of future climate, an analysis of the climatic tolerances of the species in its current range, and the fossil record to project the future distribution of Joshua trees. The study concludes that the species could be restricted to the northernmost portion of its current range as early as the end of this century. Additionally, the ability of Joshua trees to migrate via seed dispersal to more suitable climates may be severely limited.

"This is one of the most interesting research projects of my career," said Ken Cole, a USGS ecologist and the study's lead author. "It incorporated not only state-of-the-art climate models and modern ecology, but also documentary information found in fossils that are more than 20,000 years old."

By using fossil sloth dung found in desert caves and packrat middens -- basically, the garbage piles of aptly named packrats -- scientists were able to reconstruct how Joshua trees responded to a sudden climate warming around 12,000 years ago that was similar to warming projections for this century. Prior to its extinction around 13,000 years ago, the Shasta ground sloth favored Joshua trees as food, and its fossilized dung contained abundant remains of Joshua trees, including whole seeds and fruits. These fossil deposits, along with fossil leaves collected and stored by packrats, allowed scientists to determine the tree's formerly broad range before the warming event.

The study concluded that the ability of Joshua trees to spread into suitable habitat following the prehistoric warming event around 12,000 years ago was limited by the extinction of large animals that had previously dispersed its seeds over large geographic areas, particularly the Shasta ground sloth. Today, Joshua tree seeds are dispersed by seed-caching rodents, such as squirrels and packrats, which cannot disperse seeds as far as large mammals. The limited ability of rodents to disperse Joshua tree seeds in combination with other factors would likely slow migration to only about 6 feet per year, not enough to keep pace with the warming climate, Cole and his colleagues concluded.

The Joshua tree, a giant North American yucca, occupies desert grasslands and shrublands of the Mojave Desert of California, Nevada, Arizona, and Utah; Joshua Tree National Park in California is named after this iconic species. The Joshua tree is known for its distinctive shape and height of up to 50 feet.

Results of the study, "Past and ongoing shifts in Joshua tree distribution support future modeled range contraction," appear in a current edition of Ecological Applications. The research team included Kenneth L. Cole, U.S. Geological Survey; Kirsten Ironside, Northern Arizona University; Jon Eischeid, NOAA Earth Systems Research Laboratory; Gregg Garfin, University of Arizona; Phillip B. Duffy, Lawrence Livermore National Laboratory and University of California; and Chris Toney, USDA Forest Service.


Story Source:

The above story is based on materials provided by United States Geological Survey. Note: Materials may be edited for content and length.


Journal Reference:

  1. Kenneth L. Cole, Kirsten Ironside, Jon Eischeid, Gregg Garfin, Phillip B. Duffy, Chris Toney. Past and ongoing shifts in Joshua tree distribution support future modeled range contraction. Ecological Applications, 2011; 21 (1): 137 DOI: 10.1890/09-1800.1

Cite This Page:

United States Geological Survey. "Uncertain future for Joshua trees in US Southwest projected with climate change." ScienceDaily. ScienceDaily, 25 March 2011. <www.sciencedaily.com/releases/2011/03/110324153656.htm>.
United States Geological Survey. (2011, March 25). Uncertain future for Joshua trees in US Southwest projected with climate change. ScienceDaily. Retrieved August 20, 2014 from www.sciencedaily.com/releases/2011/03/110324153656.htm
United States Geological Survey. "Uncertain future for Joshua trees in US Southwest projected with climate change." ScienceDaily. www.sciencedaily.com/releases/2011/03/110324153656.htm (accessed August 20, 2014).

Share This




More Plants & Animals News

Wednesday, August 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Awesome New Camouflage Sheet Was Inspired By Octopus Skin

Awesome New Camouflage Sheet Was Inspired By Octopus Skin

Newsy (Aug. 19, 2014) Scientists have developed a new device that mimics the way octopuses blend in with their surroundings to hide from dangerous predators. Video provided by Newsy
Powered by NewsLook.com
Disquieting Times for Malaysia's 'fish Listeners'

Disquieting Times for Malaysia's 'fish Listeners'

AFP (Aug. 19, 2014) Malaysia's last "fish listeners" -- practitioners of a dying local art of listening underwater to locate their quarry -- try to keep the ancient technique alive in the face of industrial trawling and the depletion of stocks. Duration: 02:29 Video provided by AFP
Powered by NewsLook.com
USDA Cracks Down On Imports From Foreign Puppy Mills

USDA Cracks Down On Imports From Foreign Puppy Mills

Newsy (Aug. 18, 2014) New USDA measures to regulate dog imports aim to crack down on buying dogs from overseas puppy mills. Video provided by Newsy
Powered by NewsLook.com
Bone Marrow Drug Regrows Hair In Some Alopecia Patients

Bone Marrow Drug Regrows Hair In Some Alopecia Patients

Newsy (Aug. 18, 2014) Researchers performed an experiment using an FDA-approved drug known as ruxolitinib. They found it to be successful in the majority of patients. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins