Featured Research

from universities, journals, and other organizations

Predicting Boom And Bust Ecologies

Date:
October 30, 2008
Source:
University of Calgary
Summary:
While scholars may be a long way from predicting the ins and outs of the economy, biologists have uncovered fundamental rules that may govern population cycles in many natural systems.

The natural world behaves a lot like the stock market, with periods of relative stability interspersed with dramatic swings in population size and competition between individuals and species.

While scholars may be a long way from predicting the ins and outs of the economy, University of Calgary biologist Edward McCauley and colleagues have uncovered fundamental rules that may govern population cycles in many natural systems. Their discovery is published October 29 in the scientific journal Nature.

"Ecological theory has always predicted that predator-prey relationships cause large fluctuations in populations but in reality, many ecosystems are very stable," says McCauley, a populations ecologist and Canada Research Chair in the Department of Biological Sciences. "It's been a long-standing conundrum that we are now finally starting to understand."

The basis of their study is the feeding and life cycle of a tiny crustacean called Daphnia and their microscopic algal prey commonly found in lakes and ponds throughout the world. Using aquaria to keep environmental conditions as stable as possible, the researchers observed both very large and very small fluctuations in abundance of these populations over time even under the same global environmental conditions.

McCauley was able to show that the key mechanism giving rise to the small-scale fluctuations is how the availability of food affects both the maturity and mortality rate of these freshwater herbivores.

By understanding how food affects juvenile growth in populations, they were able to show using mathematical models why different types of cycles are found in predator-prey systems. Further experiments confirmed that these simple life-cycle features common to many organisms, led to the different cycles.

"Nature is often described to be in different states. For example, lakes are often characterized as to whether they are clear or turbid and these states resist changes over time. Here we are dealing with cycles in abundance being the different states -- lakes can have populations displaying large cycles or small cycles or both," says McCauley.

McCauley's work solves a fundamental problem raised over 25 years ago. Then, McCauley and his colleagues showed that Daphnia and their algal prey have an incredible range of population dynamics. They joined forces with a group of theoreticians and explored how time delays caused by food availability and energy requirements might affect population dynamics.

"In our new work, we wanted to determine how these cycles could co-exist, and our study shows that models which take into account some very general life-cycle characteristics can explain the fluctuations in these systems," says McCauley.

Their results and general models may improve our ability to explain how populations respond to different environmental changes.

"For example, will changes in temperature signals caused by climate change lead to large fluctuations in population size becoming more prevalent, or will they increase the prevalence of small amplitude cycles?" McCauley questions.


Story Source:

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


Cite This Page:

University of Calgary. "Predicting Boom And Bust Ecologies." ScienceDaily. ScienceDaily, 30 October 2008. <www.sciencedaily.com/releases/2008/10/081029141039.htm>.
University of Calgary. (2008, October 30). Predicting Boom And Bust Ecologies. ScienceDaily. Retrieved October 20, 2014 from www.sciencedaily.com/releases/2008/10/081029141039.htm
University of Calgary. "Predicting Boom And Bust Ecologies." ScienceDaily. www.sciencedaily.com/releases/2008/10/081029141039.htm (accessed October 20, 2014).

Share This



More Plants & Animals News

Monday, October 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Rare Lion Cubs Make Debut at Belgrade Zoo

Raw: Rare Lion Cubs Make Debut at Belgrade Zoo

AP (Oct. 17, 2014) Two white lion cubs were born in Belgrade zoo three weeks ago. White lions are a rare mutation of a species found in South Africa and some cultures consider them divine. (Oct. 17) Video provided by AP
Powered by NewsLook.com
The Best Foods To Boost Your Mood

The Best Foods To Boost Your Mood

Buzz60 (Oct. 17, 2014) Feeling down? Reach for the refrigerator, not the medicine cabinet! TC Newman (@PurpleTCNewman) shares some of the best foods to boost your mood. Video provided by Buzz60
Powered by NewsLook.com
Sweet Times for Hard Cider Makers

Sweet Times for Hard Cider Makers

AP (Oct. 16, 2014) With hard cider making a hardcore comeback across the country, craft makers are trying to keep up with demand and apple growers are tapping a juicy new revenue stream. (Oct. 16) Video provided by AP
Powered by NewsLook.com
Meet Garfi the Angry Cat

Meet Garfi the Angry Cat

Buzz60 (Oct. 16, 2014) Garfi is one frowny, feisty feline - downright angry! Ko Im (@koimtv) introduces us to the latest animal celebrity taking over the Internet. You can follow more of Garfi's adventures on Twitter (@MeetGarfi) and Facebook (Garfi). Video provided by Buzz60
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:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

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