Featured Research

from universities, journals, and other organizations

Can cacti 'escape' underground in high temperatures? How a certain species will potentially handle global warming

Date:
November 25, 2010
Source:
American Journal of Botany
Summary:
In the scorching summer heat of the Chihuahuan Desert in southwest Texas, air temperatures can hover around 97F (36C) while at the surface of the soil temperatures can exceed 158F (70C). Encountering these extreme temperatures, plants must utilize creative methods to not only survive but thrive under these difficult and potentially lethal conditions. New research sheds light on how one desert resident, the cactus Ariocarpus fissuratus, copes with the effects of high temperatures.

A "living rock" cactus (Ariocarpus fissuratus) in a large container on the roof of the biology building of Occidental College, Los Angeles, in June 2008 after 8 days of high temperatures. This particular plants was embedded in sandy soil with surface rocks. Scale bar = 10 mm.
Credit: Gretchen B. North, Occidental College, Los Angeles

In the scorching summer heat of the Chihuahuan Desert in southwest Texas, air temperatures can hover around 97F (36C) while at the surface of the soil temperatures can exceed 158F (70C). Encountering these extreme temperatures, plants must utilize creative methods to not only survive but thrive under these difficult and potentially lethal conditions.

This new work by Dr. Gretchen North and colleagues, published in the December issue of American Journal of Botany, sheds light on how one desert resident, the cactus Ariocarpus fissuratus, copes with the effects of high temperatures.

"One crucial point is that small desert plants such as the 'living rock' cactus occupy one of the hottest habitats on earth, the surface of desert soils" stated North.

Ariocarpus fissuratus earned its nickname "living rock" because it blends into the rocky surroundings with its small stature that is level with the soil's surface. The researchers hypothesized that the cactus could "escape" high temperatures by moving more of itself below the soil surface where it is cooler.

Measuring changes in plant depth and root anatomy, North and co-workers determined that the cactus moves deeper into the soil by contracting its roots. But does root contraction play a protective role by modulating temperatures?

To find out, the researchers mimicked summer desert conditions by growing plants on a rooftop in Los Angeles, where air temperature was above 99F for several days. All the cacti were grown in sandy soil, but half had rocks covering the surface of the soil, similar to their native habitats. For plants grown in rocky soils, the internal temperature of the stem was about 7F lower than those grown in sandy soils alone. While this may seem like a small decrease, it had a significant effect on the health of the plants.

Unlike the cacti grown in sandy soil which all died, those grown in rocky soil survived the intense heat. Root contraction aided in lowering the internal stem temperature, but only when combined with the cooling effects of the rocky surface. The opposite was true in sandy soil where cacti planted higher above the surface had slightly lower stem temperatures than those planted close to the surface.

"Even in rocky soil, experimental plants attained nearly lethal temperatures during a summer heat wave in Los Angeles" said North. "Thus, root contraction and rocky microhabitats may not provide enough protection should desert temperatures get much higher due to global warming.


Story Source:

The above story is based on materials provided by American Journal of Botany. Note: Materials may be edited for content and length.


Journal Reference:

  1. Tadao Y. Garrett, Cam-Van Huynh, Gretchen B. North. Root contraction helps protect the "living rock" cactus Ariocarpus fissuratus from lethal high temperatures when growing in rocky soil. American Journal of Botany, 2010; 97 (12): 1951-1960 DOI: 10.3732/ajb.1000286

Cite This Page:

American Journal of Botany. "Can cacti 'escape' underground in high temperatures? How a certain species will potentially handle global warming." ScienceDaily. ScienceDaily, 25 November 2010. <www.sciencedaily.com/releases/2010/11/101124162220.htm>.
American Journal of Botany. (2010, November 25). Can cacti 'escape' underground in high temperatures? How a certain species will potentially handle global warming. ScienceDaily. Retrieved September 17, 2014 from www.sciencedaily.com/releases/2010/11/101124162220.htm
American Journal of Botany. "Can cacti 'escape' underground in high temperatures? How a certain species will potentially handle global warming." ScienceDaily. www.sciencedaily.com/releases/2010/11/101124162220.htm (accessed September 17, 2014).

Share This



More Plants & Animals News

Wednesday, September 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com
Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

AFP (Sep. 16, 2014) Since the arrival of Ebola in Ivory Coast, Ivorians have been abandoning their pets, particularly monkeys, in the fear that they may transmit the virus. Duration: 00:47 Video provided by AFP
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