Seed bank of European hornbeam (Carpinus betulus L.) in the forest floor litter of a middle-aged stand for reconstruction in the area of Morović

In a high, middle-aged stand of European hornbeam, on a site of mesophilous pedunculate oak, European hornbeam and narrow-leaved ash in the unflooded part of Ravni Srem (Carpino betuli-Quercetum roboris (Anić, 1959) Rauš 1971. subass. Fraxinetosum angustifoliae Tomić, 2007), the following tree species from the natural forest community were present: narrow-leaved ash, field maple and field elm. Pedunculate oak, a primary edificator of the community and economically the most important species was absent. The stand is 55 years old and originates from a failed regeneration of pedunculate oak. Thus, the silvicultural prescription is restoration. The number of trees in the unthinned part of the stand (EP 1) was 1217 trees per hectare and in the thinned part (EP 2) 530 trees per hectare. In the thinned part of the stand, 43.5% of the total number of trees and 40% of the total number of trees of European hornbeam were counted, compared to the unthinned part of the stand. The quadratic mean diameter (dg) and dominant trees diameter (Dg20) in the unthinned part of the stand were 17.4 and 23.6 cm and in the thinned part of the stand 19.0 and 27.6 cm. The Lorey's mean height and the dominant heights were between 22.2 and 23.9 m on EP 1 and 20.5 to 22.2 on EP 2. The amount of European hornbeam seed on the soil surface in different stands is similar. In the unthinned part of the stand, the mean number of European hornbeam seeds was 1195 pcs m-2 (100%) and in the thinned part 1177 pcs m-2 (98.5%). The mean number of healthy seeds on the soil surface in the thinned and unthinned stands was 1117-1142 pcs m-2. The seeds from previous years participate with 12.2-15.0% (136-171 pcs m-2) and the seeds from the 2018 mast year 85.0-87.8% (971-981 pcs m-2), with 95% of the seeds being healthy (971-981 pcs m-2). Due to the effect of thinnings, the stands that were dominated by European hornbeam become more mixed, which is a new element that defines the process of the restoration in the future. Seedbank in the middle-aged stand designated for restoration under different managing strategies is made up of 85-88% of healthy seeds from 2018, with 12-15% from previous years.