SPATIOTEMPORAL GROWTH DYNAMICS AND DISTURBANCES IN A SUB-ALPINE SPRUCE FOREST IN THE ALPS - A DENDROECOLOGICAL RECONSTRUCTION

The recent history was reconstructed and the large-scale disturbance r egime evaluated of a subalpine spruce (Picea abies (L.) Karst.) stand in the eastern Italian Alps. A 0.4-ha plot was cut for experimental pu rposes. Living trees, dead stems, and decaying stumps were identified, labeled, and mapped. Cross sections were taken from 117 trees. Ring-w idth measurements and skeleton plot analyses were performed. Past cutt ing in the stand was reconstructed from growth releases after suppress ion and the presence of synchronous scars. The site was heavily impact ed by human activities. Timber cutting done on small patchy areas in t he past did not negatively affect the stability of the stand. The pres ence of a waiting period in many trees shows that they grew slowly und er a loose canopy. After a waiting period, a gap formed allowing their growth. The seedlings and saplings waiting under the canopy are very important to assure spatiotemporal stability. Skeleton plots are essen tial for a high resolution record of growth dynamics and disturbances. Basal cross sections contain more qualitative information than cross sections taken at higher stem levels. The method may be applied to rec onstruct stand dynamics in other regions, where historical information is scarce or completely missing.