Climate change and biodiversity are closely linked. On the one hand, the consequences of climate change are a threat to biodiversity; on the other hand, biodiversity is essential for controlling climate change and providing ecosystem services – pollination, climate regulation, protection against floods, soil fertility. Moreover, it directly affects our health by providing clean air. Biodiversity is important for the production of food, fuel, and medicines – the services that sustain our economies and societies – and is therefore essential for human well-being.

Unfortunately, we are currently witnessing a steady decline in biodiversity – the 2022 Living Planet Index shows a 69% decline in mammal, bird, amphibian, reptile, and fish populations compared to 1970. This has huge implications for the planet and the sustainability of life.

This year, Tallinn as a Green Capital will also focus on maintaining biodiversity, the climate, and sustainable governance.

In the spring of 2023, TalTech prepared a biodiversity plan for the Mustamäe campus that included a range of actions for maintaining and enhancing the biodiversity of the campus. Proposals fall into four categories: landscaping and maintenance; nesting options; communication and future monitoring; and mandatory conservation measures. One of the first and most important outputs under the landscaping and maintenance category is the new mowing plan, which will benefit pollinators, birds, and plants as well as university staff, students, and the residents of the entire city of Tallinn.

So far, the lawns of the Mustamäe campus of TalTech have been mowed at a uniform intensity, ensuring a similar height and appearance of grass everywhere. There have been years when it has only been possible to mow a few times during the summer due to drought. Now, in cooperation with Murel Truu, an expert from the Department of Civil Engineering and Architecture of the university and a member of the Biodiversity Working Group, a preliminary new mowing plan has been developed, which will be tested in the summer of 2023. It divides the green areas of the campus into four categories according to mowing regimes: a natural area left to natural succession and, where appropriate, with support for the establishment of a multi-storied stand; maintained habitats for protected species as recommended by experts in the Biodiversity Plan; 10–15 cm green lawns; and experimental grass areas left unmown.

The latter is new. Reducing mowing in particular is the first step towards encouraging biodiversity. Plant species that sprout in tall grass provide a more diverse habitat for insects, birds, and small animals. By creating biodiverse areas, we encourage and promote access to the benefits of nature in the city, which in turn is necessary to ensure that we have clean air, water, and soil.

Grass that is left unmown is cut again in autumn when the leaves turn yellow.

In order to better understand the impact of not mowing, the plots will be monitored throughout the summer. Changes in the number of species and the proportion of different species in comparison with the mown area, including changes in soil biota, will be assessed. This data, as well as feedback from the community, will provide an opportunity to analyse whether to leave the grass uncut in the coming summers and, if necessary or possible, extend this to other plots.

In the summer, everyone has a chance to spot and photograph the burgeoning wildlife on the campus and take part in a photo competition. In the autumn, the authors of the best photos will receive a sustainability prize. The photo competition will start on 1 June; more information is coming in May!