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Fig. 4.32 Rocinha favela in Rio de Janeiro (Image: Google Earth)
Fig. 4.33 Typical suburb in London (Image: Google Earth)
Especially the rich foliage of mature trees has
beneficial effects on the composition of the air.
Trees filter out solid air pollutants (dust, soot)
most effectively. Some of the main air polluting
gases (sulphur dioxide, nitrogen oxides) are also
“breathed in” by trees while plant tissues,
however, may be damaged. Different species have
different sensitivity to the pollutants. Experience
revealed that there are also particularly pollution
resistant species called urban trees.
4.1 Changes in the Outer Boundary Zone of the Earth’s Crust