Acid rain. Examination by the Forestry Commission in Freiburg, West Germany, of growth rings from the trunk of a Black Forest fir tree that shows evid

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Acid rain. Examination by the Forestry Commission in Freiburg, West Germany, of growth rings from the trunk of a Black Forest fir tree that shows evidence of acid rain damage. Each ring is an expression of one year's growth & reflects the growing conditions over the period. The fir tree examined here shows a collapse of ring growth over the last 20 years (outer rings). The rings are smaller & closer together than previous years (inner rings), indicating a stunted growth history. This is linked to acid rain pollution, the lowering of pH levels in rainfall due to sulphur dioxide emissions into the atmosphere. The cracks in the trunk are not related to acid rain.

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Size: 3612px × 2480px
Photo credit: © ADAM HART-DAVIS/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: acid, air, atmospheric, environment, environmental, growth, pollution, rain, ring, rings, tree