Different increment parameters (radial increment, top height increment and current annual increment (CAI) per hectar for volume and for basal area), which were derived from data sampled by the Austrian Forest Inventory are presented for different time spans. Special emphasis is laid on the comparability of inventory results from different time periods for basal area increment. Since 1961 inventory results show an increase in CAI per hectare for basal area of about 24% with the maximum increase from the 1970s to 1980s. Long increment core data reveal a long-term trend in radial increment for the last 100 years. Some causes like climatic changes, increasing nitrogen supply, and CO2 are discussed, but no clear cause relationships can be presented.
