Navigation Links
After drought, ponds keep up with the Joneses

An ecologist at Washington University in St. Louis has discovered that after ponds dry up through drought in a region, when they revive, the community of species in each pond tends to be very similar to one another, like so many suburban houses made of ticky tacky.

Jonathan M. Chase, WUSTL associate professor of biology in Arts & Sciences, and director of the universitys Tyson Research Center, created 20 artificial ponds out of tanks that hold 300 gallons of water. He made each pond community exactly the same in their environmental conditions, but varied the timing in which he added many species to the community lots of species, especially dragonflies, water-bugs, frogs, and even algae, happily colonized the ponds on their own accord.

As the communities thrived, most of the ponds diverged from each other some had only between 10 and 20 percent of species in common with other ponds. This factor was due to stochasticity, or randomness a plant introduced by a seed dropped from a duck, a frog having a lucky day, for instance.

But then Chase, having played beneficent god, played pernicious god, adding drought, normally random in nature, to one-half of the pond environments.

After the drought, the communities converged, and every community looked similar to each other, said Chase, who studies community assembly, among other areas of ecology. Its understandable that only certain kinds of species can stand the drought. When it comes to drought, there are wimpy species and hardy species. Several types of zooplankton, many water-bugs, and some frogs are the hardy ones. A wimpy species, perhaps surprisingly, is the bullfrog. Their tadpoles require two years to grow, so they often dont rebound very well from drought.

Some of the zooplankton have resting eggs that are deposited in mud. They rebound well when the ponds refill. Some frogs leave the pond when it dries up. Lots of different types of algae and one or two species of plant make it through, including one annual plant that makes lots of seeds, so when the pond refills again, its ready to flourish.

Go elsewhere, or die

These tough species are incumbents, which gives them an advantage when the ponds refill. They can rebuff some of the new colonists. Niches get filled in the pond and colonists trying to join the club either go elsewhere or die.

Drought homogenizes the variance among communities, Chase said. It takes all these communities that used to be very different from each other and makes them very similar to each other. Thats a very much underappreciated part of biodiversity.

Chases research was published in the Oct. 15 issue of Proceedings of the National Academy of Sciences. The National Science Foundation funds his work.

Chases findings are important to the study of biodiversity because he analyzed ponds both locally and regionally. A local analysis measures alpha diversity, which is the analysis of all the species in one pond. Chase, on the other hand, measured beta diversity, which measures the difference among ponds. If before the drought each pond had 10 species but only shared five in common, that difference is beta diversity.

I found drought had less than a 10 percent reduction on local diversity, but a nearly 50 percent reduction on regional diversity. This is important because if you just count the number of species in any given pond you might say that drought had little effect on species diversity. But if you take exact data and you ask: Did drought affect regional diversity" I found it had a huge effect on regional diversity.

Most diversity studies only have looked at local communities, which in many cases rebound very quickly following disturbances. Thus, ecologists trying to restore wetlands, prairies, or forests, could get the impression that all is needed is to build it and they will come. But Chases findings show that community assembly can sometimes be much more random than that.

Chases results have implications for wetland mitigation projects, which are often required by law. If a hundred acres of wetlands have been taken out by agriculture or a mall development, those one hundred wetland acres have to be created some place else. Ecologists are not sure exactly how to build functioning wetlands in the same way as the previous one, which had been assembled thousands of years ago. His findings give researchers better clues of how to go about restorations to restore biodiversity at both local and regional scales.

I would argue that this has important implications for how to go about restoring and creating wetlands, and that in particular, we need to think about the role of stochasticity, leading to beta diversity among otherwise similar habitats, when we restore habitats.


Contact: Tony Fitzpatrick
Washington University in St. Louis

Related biology news :

1. Mouse brain cells rapidly recover after Alzheimers plaques are cleared
2. Bone Density Recovers After Teens Stop Injected Contraceptive
3. Youth With HIV Take More Risks After New Meds Introduced
4. After a time-shift, mixed signals from the circadian clock
5. Does vitamin C help prevent or treat the common cold? Maybe not, after all.
6. Stem cell treatment improves mobility after spinal cord injury
7. Bad aftertaste? New sensory on/off switch may cure bane of artificial sweetener search
8. Drug Offers Alternative to Surgical Treatment After Miscarriage
9. New type of rejection blocker protects kidneys after transplant
10. Menopause Symptoms May Come Back After Stopping Menopausal Hormone Therapy
11. After the yeast is gone bacteria continue to develop flavor of sparkling wine
Post Your Comments:
(Date:4/11/2017)... , April 11, 2017 NXT-ID, Inc. ... technology company, announces the appointment of independent Directors Mr. ... to its Board of Directors, furthering the company,s corporate governance ... Gino ... we look forward to their guidance and benefiting from their ...
(Date:4/4/2017)... 2017   EyeLock LLC , a leader of ... States Patent and Trademark Office (USPTO) has issued U.S. ... of an iris image with a face image acquired ... company,s 45 th issued patent. ... given the multi-modal biometric capabilities that have recently come ...
(Date:3/29/2017)... -- higi, the health IT company that operates the largest ... , today announced a Series B investment from BlueCross ... new investment and acquisition accelerates higi,s strategy to create ... health activities through the collection and workflow integration of ... and secures data today on behalf of over 36 ...
Breaking Biology News(10 mins):
(Date:10/12/2017)... ... 12, 2017 , ... DuPont Pioneer and recently formed CasZyme, ... into a multiyear collaboration to identify and characterize novel CRISPR-Cas nucleases. The goal ... editing across all applications. , Under the terms of the agreement, Pioneer will ...
(Date:10/12/2017)... ... October 12, 2017 , ... ... platform specifically designed for life science researchers to analyze and interpret datasets, ... Franklin, who made a major contribution to the discovery of the double-helix ...
(Date:10/11/2017)... ... , ... ComplianceOnline’s Medical Device Summit is back for its 4th year. The ... Francisco, CA. The Summit brings together current and former FDA office bearers, regulators, industry ... officials from around the world to address key issues in device compliance, quality and ...
(Date:10/11/2017)... , ... October 11, 2017 , ... Disappearing forests and ... lives of over 5.5 million people each year. Especially those living in larger cities ... Treepex - based in one of the most pollution-affected countries globally - decided to ...
Breaking Biology Technology: