Trees in the city are suffering, due to roots being attacked by pollutants and deficiencies in water and oxygen. Scientists from the Faculty of Horticulture at Mendel University are looking for ways to cure this with grouting techniques. Photo credit: Freepik
Brno, Aug. 5 (BD) – Brno-based scientists from Mendel University’s Faculty of Horticulture are trying to assist tree species growing in urban settings. This environment is hostile to trees, and not just because of climate change. They are subjected to a variety of stresses, especially trees placed alongside highways or in pavements. One promising solution to their challenges is the so-called grouting method.
For a long time, the environment for the survival of woody plants in urban settings has been deteriorating. A negative component is the state of the soil, which frequently shows signs of improper composition and compaction. “The roots have limited space in the soil, are attacked by pollutants, and are deficient in water and oxygen,” said Petr Salaš of the MENDELU Faculty of Horticulture. “Inadequate root development also inhibits the crown from growing fully. The trees therefore become less vital and are more susceptible to illnesses and pests.”
The use of grouting equipment that can aerate the soil with air pressure is one option for improving the health of tree roots. The resulting premises are then wet injected with hydro absorbents, fertilisers, or mycorrhizal preparations. Soil aeration has the extra effect of hastening the repair of wilting roots in woody plants.
“Our team has been setting up and assessing long-term trials at several locations since 2019,” said Salaš. “We work closely with the Brno and Znojmo greenery managers on this professional endeavour (Public Greenery of the City of Brno and Municipal Greenery of Znojmo). We use specialised sensors to measure the soil temperature and moisture in the root areas of a few chosen experimental plants. We also assess the health of the trees and a few phenological indicators. We think that the injection strategy, particularly in exposed habitats, can help to improve the state of the vegetation in cities.”
The extreme variations in precipitation, i.e. long periods of drought or torrential rains, in which the soil does not manage to soak up water and the vast majority of it drains away, further deepens the drought in the soil – the most visible manifestation of global climate change in the Czech environment. This also has an effect on the wilting of trees in city avenues. Furthermore, the dirt in urban environments is excessively compacted and of poor quality, making it impossible for water to get to the roots. Climate change, according to some scientists, will have an impact on the planting and composition of trees in cities in the future. It will be necessary to seek out new tree varieties that are more resistant to harsh urban environments. so the representation of non-native tree species will continue to increase.
