Citizen science project GartenDiv researches plant diversity in Germany’s gardens

Biodiverse allotment garden. Photo: BKD
Biodiverse allotment garden. Photo: BKD

The recently launched nationwide citizen science project GartenDiv will be the first to research plant diversity in Germany’s gardens. Under the leadership of Leipzig University, the project team initially wants to gain an overview of which plants thrive in gardens across the country in a one-year pilot project. gardens are important but previously underestimated refuges of plant diversity. Although research interest in gardens has increased significantly over the last 20 years, a comprehensive survey has been lacking - and not just in Germany," explains project manager Dr. Ingmar Staude from the Institute of Biology at Leipzig University. GartenDiv aims to close this gap. The German Center for Integrative Biodiversity Research (iDiv), the Julius Kühn Institute (JKI) - Federal Research Institute for Cultivated Plants and the Federation of German Allotment Garden Associations (BKD) are involved in the project.

Questionnaires with garden-specific ID

In collaboration with the Max Planck Institute for Biogeochemistry in Jena and the Technical University of Ilmenau, the already widely used Flora Incognita app for automatic plant recognition was developed specifically for this citizen science project. The app records the plant diversity of the garden, regardless of whether it is a house garden, small garden, roof garden or balcony, by gardeners photographing the plants in their garden over the course of the year and answering questions about their observations.

At the beginning, there is a questionnaire that collects basic information about the garden, such as its size. A garden-specific ID is also generated, which enables the scientists to clearly assign additional questionnaires and observations to a specific garden as the project progresses. In addition, there is a short, observation-specific questionnaire that is completed for each plant report, for example on frequency: How many individuals of this species are growing in the garden? our long-term goal is to establish the largest citizen science project on garden biodiversity in the German-speaking world. In doing so, we not only want to create a scientific basis, but also send a social signal: Gardens count. And everyone can make a contribution," says Ingmar Staude.

Aiming for a comprehensive survey with thousands of participants

After the pilot phase, further elements such as thematic campaigns or additional questionnaires are to be gradually added in the future in order to achieve a nationwide survey with thousands of participants from all federal states. our aim is to continue GartenDiv over several years in order to be able to observe developments in plant diversity in gardens over time," says Staude. The aim of the citizen science project is also to demonstrate the potential of gardens for the protection of endangered insect species such as wild bees. However, it can not only provide scientific findings, but also promote environmental education by motivating people to increase biodiversity in their gardens, create an active community and make the ecological potential of gardens visible. Initially, existing users of the Flora Incognita app will be made aware of the project and motivated to take a more conscious look at their garden and its plant diversity.

This is the focus of the research conducted by the Institute for Bee Protection at the Julius Kühn Institute. "With their high diversity of ornamental plants, useful plants and small structures, gardens are potential hotspots for wild bees and other animal groups. Wild bees in particular need a diverse range of flowering plants, as many species specialize in very specific plant species as a source of pollen," says wild bee expert Henri Greil from the Institute for Bee Protection. Thomas Kleinworth from the Federal Association of Allotment Garden Associations in Germany (BKD) emphasizes: ,,The cooperation with science within the framework of GartenDiv means for us the chance to advance a monitoring of our plant diversity in allotment gardens throughout Germany. "

Gardens are surprisingly species-rich

"Allotment gardens and allotment sites are often true hotspots of biodiversity. Many good examples throughout Germany show how the cultivation of fruit and vegetables and the protection of species go hand in hand, thanks to the large number of committed allotment gardeners and officials," emphasizes Thomas Kleinworth, federal advisor of the BKD. For a long time, gardens were considered artificial, modern and therefore ecologically uninteresting, both in nature conservation and in research. In Germany, for example, allotment gardens are still classified in the Federal Compensation Ordinance in a similar way to grass sports fields. But this picture is beginning to change, says Ingmar Staude from the University of Leipzig. Numerous recent studies have shown that gardens can be surprisingly species-rich, especially for insects such as wild bees, but also for plants. In individual cases, up to 30 percent of native plant species have been found on just 900 square meters, including species that were considered lost in Germany. Such examples have greatly fueled scientific interest in the topic. According to Staude, a rethink is slowly gaining ground in nature conservation: The previous separation of nature and man-made spaces is becoming less important. In a world full of new, man-made ecosystems, it is becoming increasingly clear that gardens are also nature and can be part of the solution to the biodiversity problem.