University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Master / Diploma Thesis:
Tomas Piatak
(2015):
Growth response of Norway spruce stands surviving a major wind event.
Master / Diploma Thesis - Institut für Waldbau (WALDBAU),
BOKU-Universität für Bodenkultur,
pp 76.
UB BOKU
obvsg
FullText
- Abstract:
- In the National Nature Reserve Praděd in the Czech Republic a Norway Spruce (Picea abies) dominated forest area of more than 7 ha was disturbed by an unprecedented windstorm in November 2004. The functional impacts of disturbances on growth have been studied to a limited extend only. Therefore objectives of this study were (i) to characterize the forest structure of the surviving stands, (ii) to test if the wind damage causes either a release effect (improved growth) or a negative effect on growth in different age classes, and (iii) to find out which parameters contribute to changes in increment after the wind disturbance. Three age classes were investigated in the remaining stands next to the windthrow area (young, mature and old). In each class two 100m x 20m transects were sampled and 211 trees were randomly cored for dendroecological analysis. Over all the trees showed a significant increase in growth by +6.7% (α=0.004) but only the old stands performed significantly better (+15.1%, α=0.03) after the storm event. Multiple linear regression was used to identify differences in responses for each age class according to development stage, health status, competition and distance to edge. Young stands were significantly influenced by vitality, whereas high vitality classes show a growth loss and low vitality classes a positive growth response. However, vitality only explained 11.5% of the variation in increment response in the young stands. The old stands report a significant positive growth response of +38.8% at the edge of the stand and this positive growth response is decreased by -0.6% for every meter distance from the edge of the windthrown area. The final model explained 16.8% of the variation in increment response in the old transects. The mature age class was not significantly affected by any of the selected factors. Using a tree-ring assessment approach, this work contributes to a better understanding of disturbance effects following a windstorm event.
- Beurteilende(r): Vacik Harald
- 1.Mitwirkender: Seidl Rupert