Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Maths model helps to unravel relationship between nutrients and biodiversity

11.09.2008
The level of nutrients in soil determines how many different kinds of plants and trees can thrive in an ecosystem, according to new research published by biologists and mathematicians yesterday (10 September) in Nature.

For the first time ever mathematicians have modelled all the different possible relationships between nutrients and biodiversity in lab-based experimental ecosystems. They found that although nutrient availability definitely has an impact on biodiversity, the precise relationship between the two depends on which species are present in the ecosystem. This means that in some cases low levels of nutrients can lead to high levels of biodiversity.

The new study involved biologists from the University of California Santa Cruz running a lab experiment to find out how different levels of nutrients affected how many species evolved in an ecosystem. Mathematicians from Imperial College London and the University of Bath then devised a model to show how far the results could be applied to real world scenarios.

The experiments set up by the biologists in the USA consisted of mini ecosystems full of E. coli bacteria and a parasite that lives on the E. coli. These simple communities of hosts and pathogens represent complex ecosystems in the real world, like forests, in which hosts such as trees live and evolve alongside pathogens such as fungi, bacteria and viruses.

The overall aim of the study was to shed new light on the mystery of why some ecosystems such as tropical rainforests are teeming with thousands of different plant species, whereas others, like the pine forests of northern Europe, support significantly fewer types of plant life. However, investigating this phenomenon in the field can be difficult, time consuming and results hard to interpret.

Instead, the researchers used the series of mini-ecosystems in the lab, which consisted of test tubes containing E. coli bacteria, a sugary Lucozade-like liquid for the E.coli to eat, and a parasite that lives on the E. coli.

To mimic different environments, the scientists varied the amount of sugar in each different ‘ecosystem’, and then recorded how many new strains of bacteria and parasite evolved in the sugary broth over the course of 150 generations, which took 17 days.

Their results showed that as the levels of sugar in the ecosystem changed, so did the extent to which new strains evolved. This experiment showed that the highest biodiversity resulted from a low level of nutrients.

Professor Laurence Hurst from the University of Bath’s Department of Biology explains: “The results in the lab showed that varying the level of sugary food in these mini-ecosystems caused the amount of biodiversity in the ecosystems to change. This suggests that the availability of nutrients is one of the factors that affect how many different plant species live in different parts of the world. This has been shown in a lab before, but what we wanted to do was use maths to show how these results, which refer to one kind of bacteria and its parasite, can be applied to other organisms and ecosystems in the real world.”

The team from Bath and Imperial constructed a model to work out whether this inverse relationship would be the same in all ecosystems – whether in the lab or in the real world. They found that although nutrients do affect biodiversity, the precise relationship between the two varies from one ecosystem to the next, depending on what species are present.

Dr Rob Beardmore from Imperial College London’s Department of Mathematics explains: “Although there was a clear link between nutrients and biodiversity in the lab, our mathematical model showed that in some ecosystems you will find that higher levels of nutrients lead to more biodiversity, which is opposite to what our biologist colleagues found in the lab. It turns out that the precise nature of this nutrient-diversity relationship varies from one ecosystem to another, and it depends on the complex interactions between species evolving alongside each other.”

The mathematical model can be used to predict what impact different levels of nutrients will have on biodiversity in any given lab-based ecosystem. The team say their results are very important for scientists who use small scale lab experiments to investigate phenomena in the real world.

The study also provides the first real evidence that a theory known as “geographic mosaic co-evolution hypothesis” holds up in real world ecosystems. Co-author on the paper, Dr Ivana Gudelj from Imperial College, explains: “This complicated-sounding theory basically says that nutrient availability will only have an impact on the diversity of an organism, if the organism is involved in a co-evolutionary arms race with pathogens or competitors, like our E.coli was with its parasite. Our biologist colleagues have shown evidence for this in the lab, and our mathematical model suggests that the theory will also hold up in real world ecosystems too.”

Abigail Smith | alfa
Further information:
http://www.imperial.ac.uk

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

7th International Conference on Crystalline Silicon Photovoltaics in Freiburg on April 3-5, 2017

03.04.2017 | Event News

 
Latest News

DGIST develops 20 times faster biosensor

24.04.2017 | Physics and Astronomy

Nanoimprinted hyperlens array: Paving the way for practical super-resolution imaging

24.04.2017 | Materials Sciences

Atomic-level motion may drive bacteria's ability to evade immune system defenses

24.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>