Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Dead trees are alive with fungi

10.01.2018

Species-specific fungal communities colonise dead wood

So far, little research has been conducted on fungi that live on dead trees, although they are vital to the forest ecology by breaking down dead wood and completing the element cycle between plants and soil. Soil biologists from the Helmholtz Centre for Environmental Research (UFZ) have now discovered that the number of fungus species inhabiting dead trees is 12 times higher than previously thought. Once trees die they are also colonised by different fungal communities depending on their species, as the researchers report in the ISME Journal (Multidisciplinary Journal of Microbial Ecology).


Deadwood logs of different tree species were laid out at three areas of temperate forests by UFZ scientists. They want to analyse which fungus species inhabit dead trees.

Credit: Witoon Purahong

Fungi that live on trees perform an important function in the forest ecosystem by breaking down dead wood. This is no easy feat, because wood is very resilient. It is held together by a biopolymer known as lignin, which together with cellulose and hemicellulose form the cell wall of woody plants and give the wood its stability.

Fungi are able to break down the robust lignin and the flexible cellulose fibres by releasing enzymes that cause the polymers to degrade and become mineralised. As part of the ecosystem’s cycle, the leftover material becomes part of the humus layer, which gives the soil its stability and forms the substrate for a new generation of trees.

The study took the UFZ researchers to three areas of temperate forests in the Schorfheide-Chorin Biosphere Reserve, the Hainich National Park and the Schwäbische Alb Biosphere Reserve, where they laid out around 300 dead tree trunks of eleven different species, each up to four metres long.

The trees included seven deciduous species such as beech, oak, poplar and ash and four coniferous species: spruce, Scots pine, Douglas fir and larch. Three years later they returned to see what kind of fungal communities had established themselves in the trunks. The results were astonishing: "The diversity of fungi living in the trees was an order of magnitude greater than previously thought," says Dr Witoon Purahong, a soil ecologist based at UFZ in Halle and the first author of the study.

The researchers identified between 22 and 42 operational taxonomic units (OTUs) per trunk. OTU is a scientific term used by molecular biologists to describe organisms that can be equated with individual species due to their DNA but do not already have a species name of their own.

All in all, the UFZ team identified 1,254 OTUs in the dead trunks. In a previous study, researchers found just 97 fungal species living on the same logs - about 12 times fewer than the UFZ scientists have now discovered. Dead conifers generally had greater species diversity of fungi than most deciduous trees. The greatest diversity occurred on Douglas fir, larch and oak and the smallest amount of diversity on beech and hornbeam.

The reason why the UFZ soil ecologists found so many different species of fungi lies in the modern molecular technique they used. The researchers used a DNA sequencing technology known as next-generation sequencing to determine DNA markers of the fungi hidden in the wood. In previous, similar studies, only the fruiting bodies of the fungi growing on the surface of the dead trees were documented.

This gave rise to the misleading impression that only a small number of fungus species inhabit dead trees. "It’s like an iceberg: you can’t see most of the fungi because they are inside the trunks in the form of a fine mycelium," says Prof François Buscot, who heads the department of soil ecology at the UFZ. In other words, the visible fruiting bodies are only a tiny part of the entire fungal communities inhabiting a dead tree.

But it’s not just the much greater diversity of fungi than previously suspected. The UFZ soil biologists also discovered that wood-inhabiting fungi prefer certain species of trees and don’t simply have a general preference for either conifers or deciduous trees, as scientists previously assumed. They discovered seven such distinct fungal communities on deciduous trees and two on coniferous species.

For example, oak and ash each harbour very specific communities fungal species whose composition is very different from those found on other deciduous trees. In the case of the conifers, the fungi growing in dead Scots pine were clearly distinct from those found in the other coniferous species investigated. It is not yet clear why there are such marked differences between the fungal communities in different species of dead wood.

"Oak and ash have many identical characteristics, such as the wood structure and the carbon-to-nitrogen mass ratio, but they are very different when it comes to the number of fungal OTUs," says Witoon Purahong. The fungal communities found on these two species are more different from each other than compared tp any of the other tree species the team investigated, he adds.

Now the soil ecologists from UFZ in Halle will focus on identifying the mechanisms that determine whether or not a fungus colonises a particular species of tree. "The millions of years of coevolution between trees and wood-inhabiting fungi could provide an explanation for their coexistence - just as we see with symbiotic fungi, for example," says Purahong.

What is fascinating, however, as Buscot adds, is that in some cases the specialisation of fungi on dead wood is greater than the oneof symbiotic fungi on living plants. The coexistence of communities of fungi, bacteria and invertebrates living in dead wood could also account for specific colonisation strategies.

The results of this study have increased our understanding of the biodiversity of communities living in dead wood. This is important not only because it will enable us to improve the protection of wood-inhabiting fungi, which may be threatened by the expansion of forest monocultures.

It is also important because the fungi that grow in dead trees include species already known as soil-dwellers, plant pathogens or symbiosis partners, which appear to use dead wood as a temporary habitat. "Dead wood is an integral part of forest ecosystems, which plays a vital role in the function and maintenance of biodiversity," says Buscot.

Publication:
Witoon Purahong, Tesfaye Wubet, Dirk Krüger, Francois Buscot F. (2017): Molecular evidence strongly supports deadwood-inhabiting fungi exhibiting unexpected tree species preferences in temperate forests. ISME J. 2017 Oct 31, doi:10.1038/ismej.2017.177 https://www.nature.com/articles/ismej2017177

Deadwood logs of different tree species were laid out at three areas of temperate forests by UFZ scientists. They want to analyse which fungus species inhabit dead trees.
Credit: Witoon Purahong


Link to press release and images


Contact
Dr. Witoon Purahong
UFZ-Department Department of Soil Ecology
witoon.purahong@ufz.de

Prof. Dr. François Buscot
Head of UFZ-Department Soil Ecology
phone: +49 345 558 5221
francois.buscot@ufz.de

Contact Media
Susanne Hufe
UFZ press office
Tel. +49 - 341 - 235-1630
www.ufz.de/index.php?en=640

Address
Helmholtz Centre for Environmental Research - UFZ
Permoserstraße 15
04318 Leipzig
Germany
www.ufz.de

In the Helmholtz Centre for Environmental Research (UFZ), scientists conduct research into the causes and consequences of far-reaching environmental changes. Their areas of study cover water resources, biodiversity, the consequences of climate change and possible adaptation strategies, environmental technologies and biotechnologies, bio-energy, the effects of chemicals in the environment and the way they influence health, modelling and social-scientific issues. Its guiding principle: Our research contributes to the sustainable use of natural resources and helps to provide long-term protection for these vital assets in the face of global change. The UFZ employs more than 1,100 staff at its sites in Leipzig, Halle and Magdeburg. It is funded by the federal government, Saxony and Saxony-Anhalt. www.ufz.de

The Helmholtz Association contributes to solving major and urgent issues in society, science and industry through scientific excellence in six research areas: Energy, earth and environment, health, key technologies, structure of matter as well as aviation, aerospace and transportation. The Helmholtz Association is the largest scientific organisation in Germany, with 37,000 employees in 18 research centres and an annual budget of around €4 billion. Its work is carried out in the tradition of the great natural scientist Hermann von Helmholtz (1821-1894). www.helmholtz.de

UFZ press office - Susanne Hufe | Helmholtz Centre for Environmental Research (UFZ)

Further reports about: DNA Helmholtz UFZ diversity ecology forests fungi symbiotic fungi tree species

More articles from Ecology, The Environment and Conservation:

nachricht 100 % Organic Farming in Bhutan – a Realistic Target?
15.06.2018 | Humboldt-Universität zu Berlin

nachricht What the size distribution of organisms tells us about the energetic efficiency of a lake
05.06.2018 | Leibniz-Institut für Gewässerökologie und Binnenfischerei (IGB)

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: Overdosing on Calcium

Nano crystals impact stem cell fate during bone formation

Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...

Im Focus: AchemAsia 2019 will take place in Shanghai

Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.

Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...

Im Focus: First real-time test of Li-Fi utilization for the industrial Internet of Things

The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.

Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.

Im Focus: Sharp images with flexible fibers

An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.

Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...

Im Focus: Photoexcited graphene puzzle solved

A boost for graphene-based light detectors

Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Munich conference on asteroid detection, tracking and defense

13.06.2018 | Event News

2nd International Baltic Earth Conference in Denmark: “The Baltic Sea region in Transition”

08.06.2018 | Event News

ISEKI_Food 2018: Conference with Holistic View of Food Production

05.06.2018 | Event News

 
Latest News

Carbon nanotube optics provide optical-based quantum cryptography and quantum computing

19.06.2018 | Physics and Astronomy

How to track and trace a protein: Nanosensors monitor intracellular deliveries

19.06.2018 | Life Sciences

New material for splitting water

19.06.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>