Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The great feeding-frenzy: Species-rich food webs produce biomass more efficiently

05.10.2016

Researchers at the Senckenberg have discovered a feedback in food webs: species-rich ecosystems favor large, heavy animals. Even though this increases the amount of plants consumed, the plant biomass remains approximately at the same level as in species-poor ecosystems. This is due to the fact that in species-rich ecosystems, plant communities develop whose growth is more energetically efficient. The extent of biomass production in species-rich ecosystems is more stable and thereby predictable whereas species loss leads to unpredictable deficiencies, which would have to be compensated by humans, according to the paper, published today in “Nature Communications.”

On a daily basis, ecosystems reflect the maxim “Eat or be eaten” on a large scale. Plants form the basis of the food chains and are consumed by herbivores, which in turn serve as prey for the carnivores. And even these carnivores may fall victim to larger animals.


Food webs are made up of many dynamic feeding relationships; for example herbivore aphids feed on Ground Elder and are themselves eaten by hoverfly larvae. Ants, being larger than th

Copyright: Bernhard Seifert

Many of these predators near the top of the food chain are generalists; some will occasionally also eat plant material. This leads to the establishment of dense food webs, which contain numerous complex feeding relationships. But what happens when the animal diversity decreases?

A team around Dr. Florian Schneider from the Senckenberg Research Center for Biodiversity and Climate developed a new mathematical model that computes these very connections. “Using a computer, we simulated 20,000 ecosystems and the feeding processes that occur in each of them; from ecosystems that only contain a few species of animals and plant to systems with more than one hundred species.

In the beginning, it is still open which species and what number of individuals of each animal and plant species will survive until the end. A species’ body mass is the decisive factor, since it not only determines the amount of food (in animals) and the metabolism, but in particular the feeding preference, as well,” explains Schneider.

Despite an increase in herbivores, the plants’ biomass production remains stable

The results are surprising, for even in the presence of many different herbivorous animals, plants produced the same amount of biomass as in simulations with a low diversity of herbivore species. This was the case even though with increasing animal species diversity, both the amount of plants consumed as well as the intra-guild predation increased. This reconciles two previously opposing schools of thought.

It was assumed that high animal diversity generates positive effects as the dominant consumption of animal prey lessens the pressure on plant biomass, or they are more exploitative on plants, since the numerous different animal species, due to their various preferences, consume more plant species.

Species loss favors lightweights

In the model, both scenarios occur simultaneously because changes in the number of species also lead to changes in the composition of the species communities. When the overall number of animal species is lower, this favors smaller species with a lower body mass. Species-rich ecosystems, on the other hand, tend to be profitable for larger animals at the top of the food chain. “Overall, the total weight of animals in species-rich ecosystems is therefore higher than in species-poor ecosystems,” says Schneider. “Moreover, species-rich ecosystems contain a higher number of slow-growing, larger plants.”

Plants regrow more efficiently in species-rich ecosystems

This is efficient, since compared to smaller species, larger plants use less energy during the growth process, e.g., through respiration. Therefore, the more species-rich an animal community is, the more energetically efficient is the plants’ biomass production. The increased loss of biomass to consumption by larger animals is thus compensated by a reduction in plant community metabolism. This enables plants to maintain their level of biomass at an approximately equal level in species-poor as well as species-rich ecosystems.

Species extinction makes biomass production harder to predict

However not all is well in the end because human-induced species loss caused impacts the predictability of biomass production. “Our simulations show that species-rich ecosystems produce biomass at a relatively stable, predictable level. In species-poor ecosystems, on the other hand, two scenarios are likely; i.e., much more or much less biomass is produced. In many ways, the well-being of humans depends on the reliability of biomass production. Species richness therefore leads to greater security,” Schneider sums up.

Contact

Dr. Florian D. Schneider
Senckenberg Biodiversity and Climate Research Centre
Tel. +49 (0)69 7542 1914
Fd.schneider@senckenberg.de

Sabine Wendler
Press officer
Senckenberg Biodiversity and Climate Research Centre
Tel. +49 (0)69 7542 1818
pressestelle@senckenberg.de

Publication

Schneider, Florian D., Brose, U., Rall, B.C. and Guill, C. (2016): Animal diversity and ecosystem functioning in dynamic food webs, Nature Communications. Doi: 10.1038/ncomms12718

Press images may be used at no cost for editorial reporting, provided that the original author’s name is published, as well. The images may only be passed on to third parties in the context of current reporting.

The press release and images are available for download at www.senckenberg.de/presse

To study and understand nature with its limitless diversity of living creatures and to preserve and manage it in a sustainable fashion as the basis of life for future generations – this has been the goal of the Senckenberg Gesellschaft für Naturforschung (Senckenberg Nature Research Society) for almost 200 years. This integrative “geobiodiversity research” and the dissemination of research and science are among Senckenberg’s main tasks. Three nature museums in Frankfurt, Görlitz and Dresden display the diversity of life and the earth’s development over millions of years. The Senckenberg Nature Research Society is a member of the Leibniz Association. The Senckenberg Nature Museum in Frankfurt am Main is supported by the City of Frankfurt am Main as well as numerous other partners. Additional information can be found at www.senckenberg.de 

2016 is the Leibniz year. On the occasion of the 370th birthday and the 300-year death anniversary of polymath Gottfried Wilhelm Leibniz (*7/1/1646 in Leipzig, † 11/14/1716 in Hanover), the Leibniz Association is organizing an extensive topical year. Under the title “The best of all possible worlds” – a Leibniz quote – it brings into focus the diversity and timeliness of the subject matter currently studied by the scientists at the 88 Leibniz institutions across the Federal Republic of Germany. www.bestewelten.de

Sabine Wendler | Senckenberg Forschungsinstitut und Naturmuseen

More articles from Life Sciences:

nachricht Microscope measures muscle weakness
16.11.2018 | Friedrich-Alexander-Universität Erlangen-Nürnberg

nachricht Good preparation is half the digestion
16.11.2018 | Max-Planck-Institut für Stoffwechselforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

Im Focus: Penn engineers develop ultrathin, ultralight 'nanocardboard'

When choosing materials to make something, trade-offs need to be made between a host of properties, such as thickness, stiffness and weight. Depending on the application in question, finding just the right balance is the difference between success and failure

Now, a team of Penn Engineers has demonstrated a new material they call "nanocardboard," an ultrathin equivalent of corrugated paper cardboard. A square...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

European Space Talks: Weltraumschrott – eine Gefahr für die Gesellschaft?

23.10.2018 | Event News

 
Latest News

Purdue cancer identity technology makes it easier to find a tumor's 'address'

16.11.2018 | Health and Medicine

Good preparation is half the digestion

16.11.2018 | Life Sciences

Microscope measures muscle weakness

16.11.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>