Pavement Plants
At almost midway through, the “Stoeplanten” (Pavement Plants) citizen science project has been very successful. This research was initiated by Nienke Beets, who while working for the Science Communication and Society research group and Hortus Botanicus, gave her contribution to the Stoeplanten project.
Although often overlooked, pavement plants have an important role in the urban ecosystem. Not only for their inherent beauty, but also for many other reasons: they are crucial for cooling cities during hot summers, they help rainwater drainage, they trap particulate matter from the air, they feed and give shelter to insects, and they are on the food pyramid base of many larger animals.
In the Netherlands, pavement plants make up 66% of plant diversity, with over 1300 species. Despite the significant stresses of urban environments, such as drought, limited soil access, high levels of human disturbance, and herbicides; city pavement plants continue to thrive because of their remarkable adaptability. Future eco-urban planning efforts may benefit from an understanding of urban plant communities' ecology and their remarkable ability to adapt to such harsh conditions.
The Stoeplanten research project aims to find out more about pavement plant species in the Netherlands, plant communities, biodiversity hotspots, and how these can be explained by anthropogenic and non-anthropogenic factors. While doing so, the project also engages the public in observing pavement plants and raising their profile. These plants often have a bad reputation as untidy “weeds”. The project wants to overcome this and combat ‘plant blindness’, by inspiring people to take a closer look at them and appreciate their beauty. By doing so, the project hopes to inspire people to appreciate such plants and their beneficial role in urban areas, rather than eradicate them.
As part of the initiative of Hortus Botanicus to raise awareness of the important role of pavement plants, Ph.D. candidate Nienke Beets has been leading the citizen science-based research project for the past 2 years. Based in both Hortus Botanicus and the Science Communication & Society department at Leiden University, Beets launched the first call for citizen pavement plant scientists at the Weekend of Science in 2021.
Citizen Science volunteers are asked to look for plants growing between the pavement cracks in the areas around them, and to take a photograph along with GPS coordinates. To identify the species of the plant, volunteers can use the identifier on the Stoepplantjes website after uploading their photo, or the online photo library and list of the 52 most common plants on the Hortus Botanicus website. Volunteers can also use apps such as Obsidentify or PlantNet to aid identification. The data of the submitted photos along with location and species information is then made openly available on the Stoeplanten website. The volunteer activity is easy to do and is open to anyone, requiring only a smartphone and an internet connection to upload a photo and identify the species - even without any knowledge of botany.
So far, more than six thousand observations have been uploaded by more than five hundred participants, for a total of 595 species recorded - and still counting! Some of the more rare species that have been observed include the wallflower and corn salad.
Assisting Nienke Beets is master’s student Sharon van den Burg in the Biodiversity and Sustainability and Science Communication and Society programmes. As part of her internship at Hortus Botanicus, van den Burg is analyzing volunteers’ contribution to the data, as well as species distribution and richness. She is also comparing the Stoeplanten data with other data from the Floron Eindejaars Plantenjacht (end of year plant-hunt), a winter-season Citizen Science project run by the Floron Foundation with a similar protocol. She is looking for differences between the two datasets in terms of species richness, diversity, and distribution, and is also comparing the different approaches and methods of the two projects.
Beets and the Hortus Botanicus education department, headed by Hanneke Jell, are working hard to raise more awareness about the hidden beauty and beneficial role of pavement plants. They organize lessons for primary school children, exhibitions, and workshops, and have developed many useful reference resources. While walking around the city of Leiden, you might stumble across chalk circles around a pavement plant with their common name written alongside. These could be evidence of the workshops run by Beets to highlight the rich diversity of these often ignored plants, but they could also be the work of a volunteer or fan. “I’m very happy to see random botanical chalking in the streets when I don’t know who did it - it means civilians are picking up this activity to show each other that they care”.
This is one of the many signs of the success of the Stoeplanten project in engaging the public, and encouraging them to appreciate and protect such plants. People are now organizing their own activities around pavement plants, such as posting on Instagram with the hashtag #stoepplanten, or conducting pavement safaris in the city. This growing movement to recognise the important role of these small erstwhile ‘weeds’ towards strengthening the climate resilience of our cities has led to the most positive outcome so far - inspired in part by the Stoepplanten project - namely the passing of a motion by the Municipality Of Leiden to stop eradicating pavement plants outside the old city centre. The first pilot projects have now started in the Zeeheldenbuurt and Burgemeesterswijk neighourhoods of Leiden, and will run until the end of this calendar year.
By creating awareness and helping people to appreciate pavement plants, we can prevent people from eradicating them, resulting in a series of positive benefits for the environment. But for Beets and van den Burg, the importance of appreciating plants is more than just at the pavement level - it also includes a wider appreciation of the role that plants play in our living environment. For example, many of the things we use and consume in our daily lives are plant-based, and it is important for people to know their origins. Also, with the need to move off fossil fuels such as gas and oil, plants could become an important renewable energy source. “For me in sustainability, awareness plays an important role in it” says van den Burg, and if you want to people realize that, you have to start small, right on their doorstep.
“Stoeplanten plants are the most underestimated and hated plants” adds Beets. “If I can use the most hated or the most negatively spoken group of plants to inspire people and to make them enthusiastic about plants, then that really gets me going”. For Beets, Citizen Science is a combination of talking about what she loves and doing science together with the public, highlighting the interdisciplinary nature of participatory research, with both a communication aspect and an education aspect alongside the core research task.