Citizens explore the history of plants in Zurich



Wie hat sich die Pflanzenvielfalt im Kanton Zürich in den vergangenen 200 Jahren verändert?

Natural history objects consist of preserved organisms, supplemented with text information about the identification, geographical origin and the person who collected the material. For herbarium specimens of vascular plants, the plant material is pressed and dried, and mounted on paper sheets for save handling and storage. Natural history objects represent samples of data points about when and where which organisms occurred on Earth. Collections of preserved plants and animals with their accompanying information are the product of a history of some five centuries of documenting the diversity of live on Earth. They have been compiled by generations of explorers to remote places on Earth as well as by dedicated amateurs that searched nature close-by their homes. Today more than 3 billion natural history objects are stored in some 8’000 collections that are maintained at public museums and research institutions.

Natural history collections play a prominent role in documenting species diversity, and in providing the information resources for research in systematics, biogeography, and conservation biology. These collections comprise long-term datasets that allow the investigation of human induced changes in the biodiversity on Earth during the past two centuries. Such collection-based studies include investigations into geographical range changes, temporal shifts in behavioral patterns, like flowering time of plants in spring or migration to nesting sites by birds, and evolutionary change.

The so-called digitization of large samples of natural history objects is a major requirement for embracing the future of specimen management. Digitization includes the electronic registering of objects in databases and the recording of digital images. The information is presented most effectively online via internet portals. Today, many natural history collections and museums, including ours, maintain websites to present datasets of digitized specimens.

Natural history collections now maintain citizen science projects, where volonteers join forces with collection managers and scientists in order to augment the digitization and georeferencing of specimens and the transcription of written information for online presentation. Natural history collections adapt the technical tools to digitize their collections and to incorporate their information for addressing the pressing research questions about the continuously faster Global Change in our Environment. The linking of collection-based natural history science with the public by means of citizen science projects opens up a promising route towards a brighter future for natural history collections and a broader awareness about the decline in Biodiversity and in the Global Change problematics.

I would like to reinforce that local natural history societies, like botanical and zoological societies, should join forces and collaborate with public natural history collections by means of citizen science projects. The medium for such common initiatives are the collections – past and newly generated – and citizen science projects to map and monitor changes in the plant and animal diversity.


In the context of the citizen science project "Flora des Kantons Zürich" (FloZ), the Zurich Botanical Society (ZBG) aims to compare the historical and contemporary distribution of roughly 600 rare and isolated plant species in the Canton of Zurich. To this aim, nearly 90'000 findings in the combined herbaria of the University and ETH Zürich. The identification of the herbaria is verified, photographed and made available through an online portal by volunteer experts. In total, 20 voluneteers are engaged in the processing, online transcription of herbaria labels and noting the locations of findings on historical maps.  




Project members:

  • PD Dr. Reto Nyffeler, Dr. Corina Del Fabbro, Dr. Thomas Wohlgemuth
  • Combined Herbaria of the University and ETH Zurich
  • Swiss Federal Institute for Forest, Snow and Landscape Research


Graphic artist:

Tanja Hess