Vienna is fighting the summer heat: This is how we protect our city trees!

Vienna is fighting the summer heat: This is how we protect our city trees!

Stinging heat is as much a part of summertime in Vienna as the next coffee in the little bakery around the corner. But as temperatures soar, the city of Vienna is ensuring that its more than 500,000 city trees provide green shade in a variety of ways. These trees are not only a feast for the eyes, but also important players in the fight against the summer heat. The care of these valuable natural resources is the responsibility of the experienced city gardeners in Vienna, who look after the trees all year round.

Blessed is anyone who finds a shady spot under one of the numerous city trees during the heat wave. Over 150 employees support irrigation in the summer to ensure that the plants are supplied with sufficient water. Young trees in particular suffer greatly from the high temperatures. They need special attention, especially in the first four years of life, to avoid heat stress. Interestingly, trees only develop their full “climate impact” when they are around 20 years old, making them a long-term investment for a more pleasant city.

Watering system and care

The city of Vienna is currently using more than 1,000 automatically controlled irrigation systems to ensure that the plants do not dry out. Younger trees are also watered with special “watering bags” that store 75 liters of water in the root area. On hot summer days, the plants need a total of around 400,000 liters of water daily. Despite this intensive care, only 0.5 percent of the trees “failed” this year. A pleasing result for plant lovers in the city.

A study by Climate Analytics shows that large, old city trees and a dense canopy are considered effective protection against heat stress in urban areas. At a time when the urban climate is increasingly challenged by climate change, these green giants are indispensable. Not only do they act as natural air conditioning systems, but they also help filter the air and regulate the microclimate. Given this important role, it is hardly surprising that the importance of urban and street trees cannot be taken lightly.

Challenges posed by climate change

But the challenges are not easy to overcome. City trees are exposed to enormous stress from soil compaction, air and soil pollutants and the urban climate. Science shows that many tree species only live to half their potential lifespan. Climate change is also worsening the location conditions for urban greenery, which requires a targeted selection of tree species and suitable locations. The City of Vienna's concept therefore takes climate change into account as a central factor in the care and planting of trees.

Other cities are also closely watching how Vienna deals with heat stress. Intelligent urban planning that promotes generous green spaces can make a decisive contribution to reducing heat stress. The right mix of built space and open space not only supports the wellbeing of locals, but also promotes a green, vibrant urban landscape. In a study on the effects of heat in Berlin, it became clear that green urban areas play a key role in meeting the challenges of climate change.

Overall, it shows that Vienna is on a promising path to not only improve the quality of life of its citizens, but also to actively contribute to combating the climate crisis. The careful care of city trees could prove to be crucial in the coming years for an even more livable urban culture.

For further information on the City of Vienna's strategy and measures, interested readers can access the following background articles: My district, City and green and Federal Environment Agency.