Forestry expert in Freiburg,West Germany,examining growth rings from the trunk of a Black Forest fir tree with acid rain damage. He is using a Zeiss binocular microscope with extra illumination from a desk lamp. A video camera attached to the microscope records the results. Each ring is an expression of one year's growth & reflects the growing conditions over the period. Fir trees from this area show a collapse of ring growth over the last 20 years. The rings are smaller & closer together,indicating a stunted growth history. This is linked to acid rain pollution,the lowering of pH levels in rainfall due to sulfur dioxide emissions into the air | |
Lizenzart: | Lizenzpflichtig |
Credit: | Science Photo Library / Hart-Davis, Adam |
Bildgröße: | 5121 px × 3436 px |
Modell-Rechte: | Derzeit liegt noch kein Release vor. Bitte kontaktieren Sie uns vor Verwendung. |
Eigentums-Rechte: | nicht erforderlich |
Restrictions: | - |