| Tree vigor determination |
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| Spruce | Pine | Birch | Aspen | |
| No signs of weakening |  |
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| Weakened tree |  |
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| Extremely weakened tree |  |
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| Dying tree |  |
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| Dead tree (died last year) |  |
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| Dead tree (died 2 or more years ago) |  |
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This web site was developed according to the plan of the Forest Resources and Technologies (FOREST) project funded by USAID
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