Potential of natural regeneration of Quercus robur L. in floodplain forests in the southern part of the Czech Republic

Abstract

The most common way of pedunculate oak regeneration on the floodplain sites in the Czech Republic is artificial regeneration by clear-cutting. However, what is the real potential of natural regeneration of pedunculate oak? In our research object (3,355 ha of floodplain forest in the southern part of the Czech Republic – Zidlochovice region), we inventoried about 8 ha of successful natural regeneration of pedunculate oak with density ranging between 15,000 and 100,000 individuals per ha on the plots after final cut. All harvested oak dominated parent stands showed a lower stock density that ranged between 0.5 and 0.8. In the next analysis of the survival of oak natural regeneration spontaneously established in different light conditions under the shelter of parent stands we observed the highest occurrence of saplings closer to the forest edge. A sufficient density of regeneration (above 10,000 individuals per ha) was found at the distance up to 18 m from the edge, where more than 24% of direct and 30% of indirect site factor were discovered. In the stand with the full canopy closure (DSF  about 10% on average and ISF about 24%) the oak regeneration is missing and was replaced by other tree species (especially ash and field maple). In the examined area the natural regeneration of pedunculate oak should be one of the possible alternatives of floodplain forest regeneration if certain conditions are met.