Sie sind hier: Startseite News Items Biodiversity does not always improve resistance of forest ecosystems to drought

Biodiversity does not always improve resistance of forest ecosystems to drought

The results of a european project confute hitherto assumptions regarding tree diversity

Biodiversity does not always improve resistance of forest ecosystems to drought

Foto: Michael Scherer-Lorenzen

Due to climate change, parts of the world will face droughts that will affect forest health. Scientists of the EU-funded project FunDivEUROPE, which is coordinated by Prof. Dr. Michael Scherer-Lorenzen from University of Freiburg, studied the resistance of forests to drought according to the diversity of tree species. Contrary to what was commonly accepted by scientists, species diversity does not systematically improve tree resistance to drought in forest ecosystems. This result is published in the PNAS on 29 September 2014.

The extreme events induced by climate change will have drastic consequences on forest functions and services and may bring about important drought-induced die-off events. It is, however, known that biodiversity can promote forest ecosystem performance and resistance to insect pests and diseases, but whether or not diverse forests are also better adapted to deal with drought stress remains unknown.
To shed more light on the effects of biodiversity on the resistance of European forests to drought, 160 forest stands with a variety of tree diversity levels from monocultures to five species mixtures were studied across Europe (Spain, Italy, Romania, Poland, Germany). “For every region, we compared monocultures to mixed forests (up to 5 tree species) and looked at their respective capacity to resist to drought”, explains Dr. David Forrester from University of Freiburg, who also contributed to this work.

This study shows that mixed species forests are more resistant to drought stress than monocultures in some regions only: tree diversity may afford resistance to drought stress only in drought-prone areas, i.e. in regions where the frequency and severity of drought during the growing season is high. Therefore, managing forest ecosystems for high tree species diversity alone does not necessarily ensure forest adaptability to possible future severe drought events. “It might thus be of great importance to consider species identities and local climatic conditions, and not solely the degree of diversity in the mixtures, to obtain complementary use of resources and thus maintain ecosystem functions under drought stress.” concludes Dr. Damien Bonal from the French National Institute for Agricultural Research (INRA Nancy), who lead this study.


Original publication:
Grossiord C., Granier A., Ratcliffe S., Bouriaud O., Bruelheide H., Checko E., Forrester D.I., Dawud S.M., Finér L., Pollastrini M., Scherer-Lorenzen M., Valladares F., Bonal D. & Gessler A. (2014). Tree diversity does not always improve resistance of forest ecosystems to drought. Proceedings of the National Academy of Sciences. DOI: 10.1073/pnas.1411970111

Further information:


Prof. Dr. Michael Scherer-Lorenzen
University of Freiburg
Tel.: +49 (0)761 203 5014
e-mail: michael.scherer@biologie.uni-freiburg.de

Click here for a printable version (pdf) of the press release.



Benutzerspezifische Werkzeuge