The fall of the Berlin Wall 10 years ago has meant hard times for many of the city’s old trees, some of which had been fenced off from public contact by Cold War barriers until 1989. Now, massive reconstruction in Berlin has caused fluctuations in the water table, drowning the roots of many trees. Exhaust from growing traffic is also taking its toll, as is pressure to build on parcels of open land. A group of enviros is launching a test project that aims to treat trees with regular infusions of clean air and nutrients into the soil around their roots, at a cost of about $2,780 per tree. It may seem pricy, but Berlin landscape architect Achim Fauter says it’s actually a bargain because it would cost municipal authorities $780 million a year to replace the positive climatic effects of the trees on the city.

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