Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Natural enemies help scientists untangle tropical forest food webs

18.03.2004


British ecologists have gathered compelling new experimental evidence on how tropical rain forest food webs are constructed, findings that may have important implications for their environmental management.



The research reported in Nature today (18 March) demonstrates how species that never meet may nevertheless influence each other’s ecology through shared parasites, and confirms the action of an important ecological theory in the highly biodiverse rain forest environment.

Ecologists have long believed that species which have nothing in common but a ’natural enemy’ - something that eats or parasitises both of them - may interact indirectly. The patterns that result parallel those caused by traditional competition for food, hence the name given to the effect: ’apparent competition’.


To test the theory scientists conducted a painstaking field experiment in Belize, Central America, measuring the effects of removing a beetle and a fly on other species with which they share natural enemies.

The beetle and fly belong to a very diverse group of insects whose larvae, named leaf miners, feed inside the leaves of plants. To take away just these particular insect leaf miners, researchers removed all traces of the plant that sustains only them.

A year after their removal, researchers surveyed the health of the insect species that shared natural enemies with the beetle and fly and found significantly lower parasitism and significantly higher abundance.

"This is basic ecological research intended chiefly to increase our understanding of these insect communities, but it also speaks to a number of biodiversity and management issues," said Professor Charles Godfray from the Natural Environment Research Council (NERC) Centre for Population Biology at Imperial, and author of the research.

If the results are typical of herbivore communities, say the authors, the development of this theory, and its associated experimental tests, will be essential to understand the diversity and structure of insect communities, especially in the species-rich tropics.

"It suggests that removal or addition of species, for example through selective logging or the release of a biological control agent, may have knock-on effects mediated by the network of natural enemies," said Professor Godfray.

The authors of the research from the NERC Centre for Population Biology at Imperial College London and the University of Oxford carried out the large-scale field experiment at the Natural History Museum’s Las Cuevas Research Station in Belize, Central America.

Their experiment wasn’t simple or easy: while scientists have carried out tests of apparent competition along coastal shorelines and in laboratory systems, manipulative experiments on insect communities in an environment as complex as a tropical forest are difficult and challenging and have rarely been attempted. Parasitism and predation can be especially intense, and levels of insect biodiversity are exceptionally high.

Previous work at the site by the same group led by one of the authors, Dr Owen Lewis, revealed the complexity of the food web they were studying: 93 species of leaf miner were attacked by 84 species of parasitoid wasp. Of the plants that were host to leaf miners, most were attacked by a single species but the researchers found that the vine plant Lepidaploa tortuosa was home to two leaf miners - a fly and a beetle (Latin names Pentispa fairmairei and Calycomyza sp. 8 respectively).

To test the apparent competition theory the researchers removed all of the L.tortuosa in their experimental fieldwork plots, alongside a 6-km stretch of track, in December 2001. In control plots the same biomass of plant material was removed from randomly chosen plant species that were not attacked by leaf miners.

Ten to 12 months, or five to six leaf miner generations, later, the scientists returned to measure the difference the clearance had made on the amount of parasitism and abundance of insects in the leaf miner food web.

Dr Becky Morris, a postdoctoral research associate at the NERC Centre for Population Biology and first author on the paper, masterminded the experimental work in Belize, organising and carrying out the host plant clearance.

The research was supported by the Natural Environment Research Council.

Tom Miller | alfa
Further information:
http://www.imperial.ac.uk
http://www.cpb.bio.imperial.ac.uk

More articles from Life Sciences:

nachricht A Map of the Cell’s Power Station
18.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht On the way to developing a new active ingredient against chronic infections
18.08.2017 | Deutsches Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>