Germany's plant diversity is on the decline: over the last 60 years, decreases have been observed across Germany in over 70 percent of the more than 2000 species examined.
Germany's plant diversity is on the decline: over the last 60 years, decreases have been observed across Germany in over 70 percent of the more than 2000 species examined. The species dropped by an average of 15 percent. These are the findings of the most comprehensive analysis of plant data from Germany ever conducted, recently published in Global Change Biology. 29 million pieces of data on the distribution of vascular plants were taken into account in the analyses carried out within the framework of the "sMon - Biodiversity Trends in Germany" project of the German Centre for Integrative Biodiversity Research (iDiv). The study involved researchers from iDiv, the universities of Jena, Halle and Rostock, the Helmholtz Centre for Environmental Research (UFZ) and the Federal Agency for Nature Conservation (BfN) with the close involvement of the regional nature conservation agencies from all 16 federal states.
In an area covering the whole of Germany – in every grid field of approximately 5 by 5 kilometres – the decline in species diversity averages around two percent per decade. Especially vulnerable are the archaeophytes; species brought to Germany by humans before the discovery of America. Among others, these include a large proportion of accompanying field flora, such as the corn marigold and the large Venus’s looking glass, but also species such as the narrow-leaved rattle and the perennial goosefoot. On the other hand, many neophytes – those species that reached Germany after 1492, were also able to spread, such as the Himalayan balsam or the narrow-leaved ragwort. The results of this study make it clear that even this increase could not compensate for the loss in the number of species per unit of area.
Study shows gradual biodiversity decline in Germany
For this study, the necessarily large and heterogeneous data sets were brought together, for the first time in Germany, and reliably statistically evaluated. Distribution data from 2136 of the over 4300 plant species established in Germany were included in the calculations. Species with very low reporting frequencies were not included. The foundation for this was the FlorKart database, in which the Federal Agency for Nature Conservation has collated data on the distribution of flora in Germany. This data is predominantly the result of intensive mapping work by volunteers; an endeavour which is indispensable for nature conservation. The data was supplemented by further data sets from universities and other scientific institutions, but also by information on the presence of plants from private individuals. Information gaps were filled by calculating the probability of plant occurrence.
Read more at German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig
Image: The study shows that even species that are considered widespread, such as the corn poppy (Papaver rhoeas), are steadily declining in Germany. (Credit: Sebastian Lakner)
