The basic principle behind most strategies aimed at renaturalising ecosystems is to increase biodiversity by restoring natural habitat structure, which should lead to improved ecosystem services in the process. These projects often do not result in the success researchers had hoped for because the complexity of ecological relationships is so vast that it is difficult to detect the precise ecological factors that have priority over the many others in a particular case. Researchers working at the University of Montana and the UFZ have now developed a theoretical framework – the concept of ecological simplification – aimed at closing this gap. They tested it in two iconic river landscapes.
It sounds rather simple: in order to restore the original high level of biodiversity in our rivers, they should be renaturalised, i.e. returned to their original state. Yet it really is not that easy as these efforts are often limited in practice, e.g. through historical, cultural or economic factors.
Engineering structures (rip-rap and standard groynes) along the shore of the Elbe River (Germany).
M. Scholz, UFZ
Furthermore, it is profoundly difficult for on-site researchers to examine the abundance of ecological factors and find the ones that take priority from an ecological perspective. All too often the priorities for action are stipulated in terms of technical and financial feasibility. This leads to elaborate renaturalisation measures often not achieving the sought-after success. But what are the right measures? Which priorities should be set?
To help with this decision-making process, researchers have developed the concept of ecological simplification and tested it in two river landscapes. The concept assumes that natural river landscapes are highly complex. This complexity involves various components, in particular spatial heterogeneity, the connectivity between spacial compartments and historical legacy. Human activity has influenced each of these components in various ways, inevitably reducing complexity.
In other words, it simplifies the system and thus reduces the number of ecological niches in which species can coexist. By systematically observing these components of complexity, causes of the simplification can be recognised and countermeasures can be introduced to remedy them. When selecting efficient management measures, it therefore makes a big difference whether the ecological problems arise from past transformations of habitat resulting from development of human infrastructure, from a history of pollution caused by chemicals, and/or from invasion by alien species.
In the case study, researchers carefully examined two rivers that primarily differ in terms of the duration of human influence: a river section of the Missouri River in eastern Montana (USA) with comparatively low human influence, and the Elbe River that flows through populated areas of north eastern Germany where it has been influenced by intensive agricultural activity, shaped as an important shipping lane, and isolated from its flood plains over most of its length. .
The authors’ concept recognizes that man-made bank structures such as the groyne fields of the River Elbe can be optimised for biodiversity. If they have the "right" shape, they can create ecological niches and increase the variety of species living there. A comparison of both rivers shows that although the original niche diversity of a natural location cannot be fully restored, certain parameters, e.g. the variety of food for the animals, are converging back to their natural state through the influence of man-made structures.
This knowledge makes it possible to compensate for losses in the variety of species that arose as a result of reducing the cross-section of the river created to make the river navigable. However, artificially increasing the complexity of the Elbe River also creates new problems, e.g. the fact that niches emerge in which invasive species can settle. This could make it difficult for native species to repopulate in the long term. As a result, the measures introduced need to take into consideration the amount of niches created as well as their quality for native species.
The research team now needs to start underpinning the theoretical concept with specific case studies and corresponding recommendations for action. They are currently dealing with the issue of how to improve the ecological compatibility of necessary man-made structures in rivers in an international consortium.
Peipoch, Marc; Brauns, Mario; Hauer, F. Richard; Weitere, Markus; Valett, H. Maurice; (2015): Ecological simplification: human influences on riverscape complexity. http://dx.doi.org/10.1093/biosci/biv120
The study was funded in the USA by the National Science Foundation (NSF) EPSCoR Track-1 grant no. EPS-1101342 (INSTEP 3) through the Montana Institute on Ecosystems.
Prof. H. Maurice Valett, Dr. Marc Peipoch Guell
University of Montana, Montana Institute on Ecosystems and Division of Biological Sciences
Tel. +1 (0)406-243-6058
Prof. Markus Weitere, Dr. Mario Brauns
Helmholtz Centre for Environmental Research (UFZ)
Tel.: +49 (0)391-810-9600, -9140
Susanne Hufe (UFZ Press Office)
Tel.: +49 (0)341-235-1630
Susanne Hufe | Helmholtz-Zentrum für Umweltforschung - UFZ
Scientists team up on study to save endangered African penguins
16.11.2017 | Florida Atlantic University
Climate change: Urban trees are growing faster worldwide
13.11.2017 | Technische Universität München
The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.
Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....
The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.
Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...
Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.
That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...
Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.
During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....
The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.
Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...
15.11.2017 | Event News
15.11.2017 | Event News
30.10.2017 | Event News
22.11.2017 | Business and Finance
22.11.2017 | Physics and Astronomy
22.11.2017 | Physics and Astronomy