The number of plant species in many ecosystems in Europe has grown rather than shrunk over the last 100 years. However, this is not necessarily cause for celebration as this local increase is primarily due to generalists and non-native species, which compete with the original native species. Moreover, the overall number of species has not increased across Europe. These were the findings of an international research team led by Martin Luther University Halle-Wittenberg (MLU). In its latest study, published in the scientific journal “Nature Communications”, the team analysed more than 57,000 time series of plant biodiversity across various habitats in Europe.
The new study’s starting point was a typical, seemingly contradictory observation in biodiversity research: “It is well known that biodiversity is changing at the global level, with species being displaced or going extinct. However, these changes are not always so readily apparent at the local level, where the number of species may even increase initially,” explains Dr Stephan Kambach, an ecologist at MLU, who led the study along with Dr Ute Jandt and Professor Helge Bruelheide.
Working with researchers from a total of 21 countries, the three scientists produced the first detailed Europe-wide analysis of how local plant biodiversity has changed over the past 100 years. To do this, the team used more than 57,000 so-called vegetation-plot time series, in other words, systematic surveys of plant communities carried out repeatedly over a long period of time at the same location. The data was also categorised according to habitat and how it has changed over time; specifically, whether a habitat has remained stable, has changed naturally, or has been disrupted by human activity. “Our analysis is the largest study to date on the changes to Europe’s local plant communities. In addition to identifying general trends in various aspects of plant biodiversity, we have been able, for the first time, to provide detailed information about most European habitat types,” explains Helge Bruelheide.
Over the last century, the number of species has risen by an average of 0.2 per cent per year in Europe. However, there were significant variations depending on the habitat. The biggest changes were observed in wetlands and marshlands, particularly where these habitats had been disturbed or overgrown by trees and shrubs. In contrast, the changes were much less pronounced in grasslands. “We saw that, on the local scale, there are actually more plant species than there used to be. But on closer inspection, these were mainly generalists and non-native species. This increase is therefore not a sign of an intact habitat but often an indication of precisely the opposite,” says Kambach. Adaptable generalists have the ability to displace native specialist and rare plants over the long term. This is supported by another finding: the total number of species found across all areas of a given habitat type in Europe has not increased, despite the arrival of new species. “Species displacement and extinction are slow processes that can only be observed and documented over long periods of time,” adds Kambach. If the trends observed by the researchers continue into the future, species numbers could decline even in areas where populations are currently stable.
“Our study would not have been possible without the decades of data collected by botanists from across Europe. It also highlights how important the continuous, Europe-wide monitoring of local plant communities is,” says Ute Jandt. She coordinates the Europe-wide project “MOTIVATE” at MLU. The project is funded by the European Commission and various national research funding bodies as part of the Biodiversa+- partnership. Project partners are from Rostock (Germany), Oulu (Finland), Brno (Czech Republic), Vienna (Austria), Oviedo (Spain), as well as Bologna and Rome (Italy).
Study : Kambach S. et al. Habitat-specific trends in taxonomic, functional, and phylogenetic diversity in European plant communities over a century. Nature Communications (2026). doi: 10.1038/s41467-026-72112-5
Nature Communications
Observational study
Not applicable
Habitat-specific trends in taxonomic, functional, and phylogenetic diversity in European plant communities over a century
8-May-2026
The authors declare no competing interests.