Green tramlines: biodiversity or spreading invasive species?
At first glance, Zürich’s green tram tracks may seem like a simple aesthetic upgrade. But these narrow strips of vegetation could be doing far more than just making the city look greener. Students from the GEO410 Geography.Matters. course describe the different types of green tram tracks and explore whether this green infrastructure unintentionally helps to spread invasive plant species.
Have you ever noticed the different green tram tracks in the city of Zürich? Green tramlines are strips of vegetation that replace conventional gravel or concrete between tram tracks. First introduced in several European cities in the late 20th century, they were primarily designed to reduce noise, cool urban areas, and improve stormwater retention. Over time, they have also become a visible symbol of greener urban transport infrastructure.
Green tramlines raise intriguing ecological questions. As linear green structures running through cities, they can resemble corridors that connect fragmented habitats, potentially influencing how plants and animals move across urban landscapes. At the same time, these spaces are shaped by intense disturbance, specific management regimes, and constant interaction with human activity. This combination makes them very different from parks or semi-natural green spaces—and potentially important in their own right.
Are green tramlines simply decorative additions to urban infrastructure, or do they play a more active role in shaping urban biodiversity? Could they support native plant species, facilitate movement, or even unintentionally aid the spread of invasive or non-native plants? And what does this mean for how cities plan and manage green infrastructure in the future?
For answers to these questions, take a look at the in-depth blog post that we produced in the context of the Geography. Matters. module at the Department of Geography in the fall semester of 2025.
Green Tramlines: Biodiversity or Spreading Invasive Species?
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| About GEO410 This blog post is part of the outcome of an interdisciplinary Master’s-level course in Geography: GEO410 Geography. Matters. The course aims to bring together diverse geographic research perspectives to engage with some of the most pressing societal and environmental challenges of our time. As the only compulsory module of the Geography MSc program, the course encourages students to think across sub-disciplines of geography and to explore how geographic research can meaningfully contribute to debates around sustainability, justice, and environmental change. Beyond conducting interdisciplinary research as a team, a central aim of the course was to experiment with creative and accessible forms of science communication. Rather than producing a purely academic output, students translated their research insights into blogposts, intended for a wider, non-specialist audience. The contributions thus showcase not only rigorous scientific work by highly motivated students, but also the importance of communicating research beyond the university and engaging broader publics in conversations about geography, sustainability and the future of our shared environments. The students in the course GEO410 were supervised by Andreas Vieli, Christian Berndt and Sofia van Moorsel as lecturers and by Nikolas Klaudy as teaching assistant. |