Featured Research

from universities, journals, and other organizations

Are Fires More Important Than Rain For The Savannah Ecosystem?

Date:
September 26, 2008
Source:
Helmholtz Association of German Research Centres
Summary:
Natural grass fires are evidently more important for the ecology of savannahs than has previously been assumed. This is the finding of a study carried out in Etosha National Park in the north of Namibia. It is the first study to have investigated the complex interplay of the factors fire, competition, moisture and seed availability in relation to a grass species.

The Etosha National Park in the north of Namibia is the second largest nature reserve in Africa, measuring 20,000 square km.
Credit: Julia Zimmermann/UFZ

Natural grass fires are evidently more important for the ecology of savannahs than has previously been assumed. This is the finding of a study carried out in Etosha National Park in the north of Namibia.

It is the first study to have investigated the complex interplay of the factors fire, competition, moisture and seed availability in relation to a grass species. Periodic fires in semi-arid regions can lead to older tufts of grass disappearing, thereby making room for younger grasses. Writing in the Journal of Ecology, the researchers from the Helmholtz Centre for Environmental Research (UFZ), the University of Frankfurt am Main and the University of Cologne say that fire therefore plays an important role in regeneration.

The findings are particularly significant for the management of semi-arid nature reserves, in which, in the absence of natural plant eaters, fires are the only practical means of renewing the grass canopy.

For the study, the researchers selected an area measuring 500 by 500 metres in Etosha National Park because it has one dominant grass species and because it was possible to rule out interference such as grazing and other human influences. Etosha National Park in the north of Namibia is the second largest nature reserve in Africa, measuring 20,000 square kilometres. The temperatures in the semi-arid savannah fluctuate between 6 degrees centigrade in the winter and 35 degrees in the summer. The area under investigation is one of the driest areas in which plants can still grow, with annual rainfall of just 380 mm. That is less than the rainfall in the rain shadow of the Harz mountains.

Stipagrostis uniplumis is the dominant grass species and lives for several years. The researchers observed the growth of these grasses at weekly intervals for one season and measured the most important climate parameters. They also experimented on small areas by sowing additional seeds, carrying out controlled reconstructions of fires, planting competing grass species and using artificial irrigation. They found that the dead grass layer significantly hindered the recruitment of young plants.

Fire can break up the old grass layer, thereby creating opportunities for regrowth. By contrast, artificial irrigation and the addition of seeds did not result in higher recruitment of seedlings.


Story Source:

The above story is based on materials provided by Helmholtz Association of German Research Centres. Note: Materials may be edited for content and length.


Journal Reference:

  1. Zimmermann et al. Recruitment filters in a perennial grassland: the interactive roles of fire, competitors, moisture and seed availability. Journal of Ecology, 2008; 96 (5): 1033 DOI: 10.1111/j.1365-2745.2008.01409.x

Cite This Page:

Helmholtz Association of German Research Centres. "Are Fires More Important Than Rain For The Savannah Ecosystem?." ScienceDaily. ScienceDaily, 26 September 2008. <www.sciencedaily.com/releases/2008/09/080919183823.htm>.
Helmholtz Association of German Research Centres. (2008, September 26). Are Fires More Important Than Rain For The Savannah Ecosystem?. ScienceDaily. Retrieved April 17, 2014 from www.sciencedaily.com/releases/2008/09/080919183823.htm
Helmholtz Association of German Research Centres. "Are Fires More Important Than Rain For The Savannah Ecosystem?." ScienceDaily. www.sciencedaily.com/releases/2008/09/080919183823.htm (accessed April 17, 2014).

Share This



More Plants & Animals News

Thursday, April 17, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Great British Farmland Boom

The Great British Farmland Boom

Reuters - Business Video Online (Apr. 17, 2014) Britain's troubled Co-operative Group is preparing to cash in on nearly 18,000 acres of farmland in one of the biggest UK land sales in decades. As Ivor Bennett reports, the market timing couldn't be better, with farmland prices soaring over 270 percent in the last 10 years. Video provided by Reuters
Powered by NewsLook.com
Change of Diet Helps Crocodile Business

Change of Diet Helps Crocodile Business

Reuters - Business Video Online (Apr. 16, 2014) Crocodile farming has been a challenge in Zimbabwe in recent years do the economic collapse and the financial crisis. But as Ciara Sutton reports one of Europe's biggest suppliers of skins to the luxury market has come up with an unusual survival strategy - vegetarian food. Video provided by Reuters
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. Video provided by Newsy
Powered by NewsLook.com
Thousands Of Vials Of SARS Virus Go Missing

Thousands Of Vials Of SARS Virus Go Missing

Newsy (Apr. 16, 2014) A research institute in Paris somehow misplaced more than 2,000 vials of the deadly SARS virus. 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