From the violet meadow sage and the pink sainfoin to the yellow anthyllis and the red poppies: wild flowers in vibrant spring colours light up the path along the south facade of the HCI building. A bumblebee dips into a sage bloom to extract the sweet nectar. The Hönggerberg campus is not just a hub of science. It is also home to all manner of animals and plant life, serving as a space for biodiversity within a settlement area.
Biodiversity – that is, the variety of life – is an important issue in today’s world. At the start of May this year, the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) warned of the accelerated extinction of biological species. An IPBES press release reported that up to one million of a total of eight million species are at risk. In the face of statistics such as this, it is important to consider the biodiversity at the ETH Zurich sites and to think about the steps the university is taking to maintain and promote the variety of species it plays host to.
Biodiversity on the Hönggerberg campus
Depending on the time of year, you’ll find a whole host of insects with weird and wonderful names while roaming around the ETH campus, such as bush crickets, grasshoppers or southern hawker dragonflies. You’ll also find birds, from house sparrows fighting over crumbs on the main square to wood pigeons with bright white patches on their throats, or the inconspicuous spotted flycatcher hunt¬ing insects from the treetops. Red kites and hobbies can also be spotted from time to time wheeling across the sky.
Situated close to forest areas and suitable spawning waters, ETH’s Hönggerberg campus is also an important habitat for amphibians in the city area. In the spring, alpine newts, common toads and common frogs set out on their travels, with the ponds near the sports hall being one of their favourite haunts. Mammals, too, feel right at home on the campus. Hedgehogs, badgers and foxes have made their homes there, and deer cross over from the Käferberg to the Hönggerberg forest.
Dedication pays off
One reason for this variety of species is the fact that the green spaces at ETH Zurich have been ecologically enhanced and maintained for many years. Fritz Graber has been responsible for looking after these areas on the Hönggerberg campus for almost 20 years. Together with one member of staff and external gardeners, he cultivates 6 hectares of turf, sports fields and alkaline grassland, as well as 13 hectares of meadowland. This area is not fertilised and is only mowed two or three times a year to enable biodiversity to thrive. Green area managers at ETH also maintain 1,300 trees on the Hönggerberg campus, including ecologically valuable deciduous trees such as oaks. As a reward for its efforts, the Hönggerberg campus has twice been recognised as a “nature park of the economy” by the Stiftung Natur & Wirtschaft association for nature and economics.
Graber certainly hasn’t been resting on his laurels. At the instigation of Zurich-based green initiative Grün Stadt Zürich, he had a dozen native fruit and nut trees planted around the SeedCity garden. These trees are an important element in ensuring biodiversity.
Special measures had to be taken in order to protect the amphibians. ETH employees covered all shafts on the buildings with finely woven wire mesh or installed escape routes for the animals, saving the lives of hundreds of frogs, toads and newts.
Biodiversity is also being encouraged on the rooftops – the most recent example of this being the roof renovation on the HPM building. The gardeners added pioneer plants to the roof, itself covered in a variety of substrates. These plants are able to withstand dryness and heat. A variety of wild bees and plants which wouldn’t otherwise be found on the campus benefit from such low-humus and dry areas.
“Artificial crag” attracts bats
