Trees in metropolitan areas have been growing faster than trees in rural areas worldwide since the 1960s. This has been confirmed for the first time by a study on the impact of the urban heat island effect on tree growth headed by the Technical University of Munich (TUM). The analysis conducted by the international research team also shows that the growth of urban trees has already been exposed to changing climatic conditions for a long period of time, which is only just beginning to happen for trees in rural areas.

Trees in metropolitan areas have been growing faster than trees in rural areas worldwide since the 1960s. This has been confirmed for the first time by a study on the impact of the urban heat island effect on tree growth headed by the Technical University of Munich (TUM). The analysis conducted by the international research team also shows that the growth of urban trees has already been exposed to changing climatic conditions for a long period of time, which is only just beginning to happen for trees in rural areas.

"While the effects of climate change on tree growth in forests have been extensively studied, there is little information available so far for urban trees", said Professor Hans Pretzsch from the Chair for Forest Growth and Yield Science at TUM. The study supported by the Bavarian State Ministry for Environment and Consumer Protection as well as by the Audi Foundation for the Environment, which was published in the journal "Nature Scientific Reports", for the first time systematically examined the growth of urban trees worldwide for trends resulting from changing environmental conditions.



A central motivation for Professor Pretzsch’s team is the prevailing trend towards global urbanization: According to calculations by the United Nations, the urban population worldwide is expected to increase by more than 60 percent by 2030 – with a continuing upward trend. Urban trees already improve the climate in cities and contribute to the well-being and health of city dwellers, and these forecasts show that their significance for the quality of life in cities will increase even further in the future.

Read more at Technical University of Munich (TUM)

Image: For the study, samples of heartwood from trees in major cities such as here in Vietnam's capital Hanoi were taken and analyzed. (Photo: TUM)