Growth characteristics, water distribution in stems, horizontal and vertical electrical resistance of living tissue, and response to mechanical injury were studied on 35 felled and 428 growing silver fir (Abies alba Mill.) trees from two representative Dinaric silver fir-beech stands (Bistra and Ravnik). Radial growth at breast height proved to be the most sensitive indicator of tree health. Affected silver fir trees are characterised by dehydration of the sapwood and the appearance of wet wood at the location of the uncoloured heartwood radiating into the sapwood ('pathological wet heart'). The horizontal (in standing trees) and vertical (in cross-sections of the discs) electrical resistance of living tissues is a sensitive indicator of tree health or social status. The response of trees to wounding is diverse and manifests itself in (a) 'fossilisation' of older differentiating cells in the cambium zone, (b) severe parenchymatization due to the release of bark pressure and growth stresses in the wood (formation of the barrier zone), and (c) 'juvenilisation' and (d) disorientation of cells after wounding.
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