Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Species Richness – a false friend? Scientists want to improve biodiversity assessments

01.08.2017

Assessing the state of an ecosystem solely on the basis of short-term changes in the number of different species it contains can lead to false conclusions. This is according to a new analysis by an international team including researchers of the Helmholtz Institute for Functional Marine Biodiversity (HIFMB) at the University of Oldenburg and the German Centre for Integrative Biodiversity Research (iDiv). In order to assess ecosystems in a way that is meaningful for nature conservation, experts should instead analyse the turnover of species within a system. The research, based on a mathematical model and environmental data analysis, is published online in the "Journal of Applied Ecology".

A growing number of species are under threat of extinction – in particular due to global environmental changes. Political instruments such as the International Convention on Biological Diversity or the EU's Marine Strategy Framework Directive aim to mitigate this biodiversity crisis.


Biodiversity of a meadow in the Austrian Alps. Photo: Gernot Kunz

In practice, taking the number of species (species richness) as a simple metric for determining the state of an ecosystem seems an obvious approach. "But this metric has its pitfalls because it doesn't fully reflect the changes in the system," says the Oldenburg biodiversity expert Hillebrand points out who is also the lead author of the study.

On the contrary, according to the scientists' model calculations, negative influences on an ecosystem do not automatically result in a reduction in species richness. Conversely, the number of species in a system does not automatically increase as soon as an ecosystem recovers from human impact. The reason for this is: "Species richness is a result of the balance between the immigration and the extinction of species."

However, these two processes do not occur at the same speed, Hillebrand explains. A few individuals of a species can quickly migrate into a local habitat and colonise it, but it may take several generations for a species to be replaced by a new, more competitive species, or to die out as a result of changed conditions.

"This means you can't reliably say, on the basis of short-term trends, whether more or fewer species will be left in an ecosystem over a long period of time," Hillebrand stresses, adding: "So species richness can be a false friend."

In their publication the scientists therefore recommend closer monitoring of how many species are migrating into a system, how many are leaving it, and how many species are becoming more or less abundant within the system. As an example the scientists used this method to analyse long-term measurements from various ecosystems - such as data on drifting microalgae (phytoplankton) from the mud flats of the Dutch Wadden Sea and the lakes of North America, as well as data from grassland ecosystems on six different continents.

“In extreme cases, the majority of species in an ecosystem could be replaced by new species. But if you only look at the number of species, the so-called species richness, that number doesn’t change at all”, says Prof. Dr. Jonathan Chase of the German Centre for Integrative Biodiversity Research (iDiv) and the Martin Luther University Halle-Wittenberg. “Therefore, species richness alone can be a misleading metric and can obscure what is really going on in an ecosystem.”

For their analyses the researchers explicitly used data gathered by conservationists in environmental monitoring programmes. In this way the scientists want to ensure that their tool can be used with the available resources, which in practice are often limited. "We hope that in this way we can build a bridge between the basic research and nature conservation in practice," Hillebrand says.

Publication: Helmut Hillebrand, Bernd Blasius et al. (2017). Biodiversity change is uncoupled from species richness trends – consequences for conservation and monitoring. Journal of Applied Ecology. DOI: 10.1111/1365-2664.12959

Weitere Informationen:

http://www.hifmb.de
http://www.icbm.de
http://www.idiv.de

Dr. Corinna Dahm-Brey | idw - Informationsdienst Wissenschaft

More articles from Ecology, The Environment and Conservation:

nachricht Rain is important for how carbon dioxide affects grasslands
06.03.2019 | University of Gothenburg

nachricht Northeast-Atlantic fish stocks: Recovery driven by improved management
04.02.2019 | Johann Heinrich von Thünen-Institut, Bundesforschungsinstitut für Ländliche Räume, Wald und Fischerei

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Revealing the secret of the vacuum for the first time

New research group at the University of Jena combines theory and experiment to demonstrate for the first time certain physical processes in a quantum vacuum

For most people, a vacuum is an empty space. Quantum physics, on the other hand, assumes that even in this lowest-energy state, particles and antiparticles...

Im Focus: Sussex scientists one step closer to a clock that could replace GPS and Galileo

Physicists in the EPic Lab at University of Sussex make crucial development in global race to develop a portable atomic clock

Scientists in the Emergent Photonics Lab (EPic Lab) at the University of Sussex have made a breakthrough to a crucial element of an atomic clock - devices...

Im Focus: Sensing shakes

A new way to sense earthquakes could help improve early warning systems

Every year earthquakes worldwide claim hundreds or even thousands of lives. Forewarning allows people to head for safety and a matter of seconds could spell...

Im Focus: A thermo-sensor for magnetic bits

New concept for energy-efficient data processing technology

Scientists of the Department of Physics at the University of Hamburg, Germany, detected the magnetic states of atoms on a surface using only heat. The...

Im Focus: The moiré patterns of three layers change the electronic properties of graphene

Combining an atomically thin graphene and a boron nitride layer at a slightly rotated angle changes their electrical properties. Physicists at the University of Basel have now shown for the first time the combination with a third layer can result in new material properties also in a three-layer sandwich of carbon and boron nitride. This significantly increases the number of potential synthetic materials, report the researchers in the scientific journal Nano Letters.

Last year, researchers in the US caused a big stir when they showed that rotating two stacked graphene layers by a “magical” angle of 1.1 degrees turns...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

International Modelica Conference with 330 visitors from 21 countries at OTH Regensburg

11.03.2019 | Event News

Selection Completed: 580 Young Scientists from 88 Countries at the Lindau Nobel Laureate Meeting

01.03.2019 | Event News

LightMAT 2019 – 3rd International Conference on Light Materials – Science and Technology

28.02.2019 | Event News

 
Latest News

Researchers measure near-perfect performance in low-cost semiconductors

18.03.2019 | Power and Electrical Engineering

Nanocrystal 'factory' could revolutionize quantum dot manufacturing

18.03.2019 | Materials Sciences

Long-distance quantum information exchange -- success at the nanoscale

18.03.2019 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>