Nav: Home

Eat or be eaten

February 26, 2020

For the first time, they did not just investigate one feeding type such as herbivores but the integrated feeding relationships across an entire ecosystem. Previous research examining the effects of biodiversity on the functioning of ecosystems focused mainly on single feeding levels (trophic levels) or simplified food chains.

"We have analyzed an entire feeding network - in other words, multitrophic interactions - above- and belowground. This is indispensable for understanding the effects resulting from global species extinction," explained Dr. Sebastian T. Meyer, a researcher at the Chair for Terrestrial Ecology at the Technical University of Munich (TUM) and lead author of the study.

A network of energy

An aboveground food chain could extend from grasses to grasshoppers and on to spiders, for example. The research group examined how much energy flows into the system, how much remains in the system - so how much biomass is present in the system - and eventually, how much energy is leaving the system. The main insight: The entire ecosystem's efficiency rises across all feeding levels when plant diversity increases.

"Seeing positive effects on one level does not imply that there cannot be simultaneous positive effects on other feeding levels," said Dr. Meyer. When a grasshopper feeds on grasses until it is saturated, this does not necessarily result in negative effects on the plant level - with a high level of biodiversity, the system keeps itself in a balance.

Unique database from a grassland biodiversity experiment

The group worked with data gathered through the Jena Experiment, a large-scale grassland biodiversity experiment that has been running since 2002. The research environment provided by the experiment is unique in the world and allow for the synthesis of large amounts of data.

For each of the 80 plots of the Jena Experiment, the researchers assembled trophic network models of the grassland ecosystem. These contain the standing biomass on every feeding level and the flow of energy through feeding interactions between the trophic levels. In addition to plants, the study also covers herbivores, carnivores, omnivores, soil microbes, dead organic material aboveground and in the soil and decomposers that feed on these sources of organic matter.

More efficient energy use in ecosystems with higher plant diversity

"The study shows that higher plant diversity leads to more energy stored, greater energy flow and higher energy-use efficiency in the entire trophic network, therefore across all trophic levels," explained Dr. Oksana Buzhdygan from Freie Universitaet Berlin, another lead author of the study.

Ecosystems with 60 plant species contained, on average, twice the amount of standing biomass in comparison to plant monocultures, which means that the total amount of resources used and recovered by plant and animal community rose with an increase in plant diversity.

Biodiversity as insurance against environmental fluctuations

"An enhanced ecosystem functionality on all levels can contribute to an increased insurance effect of biodiversity on ecosystem functions when environmental fluctuations occur; it also enhances the system's robustness in case of perturbations," Prof. Jana Petermann from the University of Salzburg concluded. She is the senior author of the study.

This research paper highlights the importance of biodiversity for functions in and services provided by ecosystems. For instance, agricultural land use that aims at yielding a wide range of goods and services should maintain high plant diversity, for example by planting mixed crops, in order to avoid losing ecosystem resources.
-end-
Further information: In the so-called "Jena Experiment" (http://www.the-jena-experiment.de), scientists from various universities in Germany, the Netherlands and Switzerland study the significance of biological diversity (biodiversity) for ecosystems. Grasslands of varying diversity are used as a model system. In the year 2002, plant communities of 1-60 plant species and 1-4 plant functional groups (based on a species pool of 60 species) were sown to measure and compare flows in biogeochemical cycles and the interactions between organisms. The results show that a higher plant diversity leads to multifaceted positive effects for these cycles and other processes in the ecosystem. Many of the results from the examined model systems can be applied to other ecosystems as well as agricultural areas.

The Chair of Professor Wolfgang Weisser is part of the Hans-Eisenmann-Forum (HEF) for Agricultural Sciences, a Central Institute of TUM.

Technical University of Munich (TUM)

Related Biodiversity Articles:

About the distribution of biodiversity on our planet
Large open-water fish predators such as tunas or sharks hunt for prey more intensively in the temperate zone than near the equator.
Bargain-hunting for biodiversity
The best bargains for conserving some of the world's most vulnerable salamanders and other vertebrate species can be found in Central Texas and the Appalachians, according to new conservation tools developed at the National Institute for Mathematical and Biological Synthesis (NIMBioS) at the University of Tennessee, Knoxville.
Researchers solve old biodiversity mystery
The underlying cause for why some regions are home to an extremely large number of animal species may be found in the evolutionary adaptations of species, and how they limit their dispersion to specific natural habitats.
Biodiversity offsetting is contentious -- here's an alternative
A new approach to compensate for the impact of development may be an effective alternative to biodiversity offsetting -- and help nations achieve international biodiversity targets.
Biodiversity yields financial returns
Farmers could increase their revenues by increasing biodiversity on their land.
Biodiversity and wind energy
The location and operation of wind energy plants are often in direct conflict with the legal protection of endangered species.
Mapping global biodiversity change
A new study, published in Science, which focuses on mapping biodiversity change in marine and land ecosystems shows that loss of biodiversity is most prevalent in the tropic, with changes in marine ecosystems outpacing those on land.
What if we paid countries to protect biodiversity?
Researchers from Sweden, Germany, Brazil and the USA have developed a financial mechanism to support the protection of the world's natural heritage.
Grassland biodiversity is blowing in the wind
Temperate grasslands are the most endangered but least protected ecosystems on Earth.
The loss of biodiversity comes at a price
A University of Cordoba research team ran the numbers on the impact of forest fires on emblematic species using the fires in Spain's Doñana National Park and Segura mountains in 2017 as examples
More Biodiversity News and Biodiversity Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Reinvention
Change is hard, but it's also an opportunity to discover and reimagine what you thought you knew. From our economy, to music, to even ourselves–this hour TED speakers explore the power of reinvention. Guests include OK Go lead singer Damian Kulash Jr., former college gymnastics coach Valorie Kondos Field, Stockton Mayor Michael Tubbs, and entrepreneur Nick Hanauer.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Dispatch 6: Strange Times
Covid has disrupted the most basic routines of our days and nights. But in the middle of a conversation about how to fight the virus, we find a place impervious to the stalled plans and frenetic demands of the outside world. It's a very different kind of front line, where urgent work means moving slow, and time is marked out in tiny pre-planned steps. Then, on a walk through the woods, we consider how the tempo of our lives affects our minds and discover how the beats of biology shape our bodies. This episode was produced with help from Molly Webster and Tracie Hunte. Support Radiolab today at Radiolab.org/donate.