Dispersal ecology of the dominant tree species (Picea abies, Abies alba, Fagus sylvatica) in the old growth forest Rothwald (Lower Austria).

The focus on ¿close to nature forestry¿ and the need for cutting costs in forest management gave rise to an increasing interest in natural regeneration of forests. Natural regeneration contributes substantially to biodiversity conservation efforts. This is reflected in the Austrian forestry act from 2002 where nature regeneration received increased attention. The early life stages represent the most critical life phase of trees. Particularly in mountain forests, knowledge gaps in regeneration ecology are pronounced. This study focuses on dispersal distances of Fagus sylvatica, Abies alba and Picea abies. The gregarious flowering pattern of many of our tree species and the resulting need for long monitoring of seed dispersal patterns makes studies on dispersal distances particularly difficult. With this study, we use a combination of experiments in wind channels, statistical approaches and models on seed dispersal to overcome these problems. For the statistical methods we use data on the spatial distribution of potential mother trees and relate it to the spatial pattern and the micro-site of germinants using maximum likelihood methods (sensu Ribbens et al. 1995). The data on spatial distribution was gained in the framework of another project funded by the Austrian Science Fund. We use seed traps on permanent sample plots and data from wind channel experiments for parameterising and testing models on seed dispersal which were developed for closed canopy situations. The gained knowledge on dispersal distances will allow for improvement of assessments on the potential of natural regeneration in mountain forests.