Biology session

Shelterwood management system is a widely applied forest management system, which can modify profoundly the natural structure and composition of forest stands. It creates evenaged, compositionally and structurally homogeneous forests, reduces the ratio of non-dominant tree species. In these forests amount of dead wood is generally much lower than in natural ones. As natural compositional and structural elements of the forests are highly important to many forest-dwelling species (e.g. bird, fungi, moss, invertebrate species), conservation management actions targeting the enhancement of forest structure and composition are spreading.

The Ecological and Botanical Institute of MTA ÖK have started a survey on the effects of the conservation management actions of Bükk National Park Directorate in a 34 ha oak dominated forest stand in 2014. The complex conservation management action opened the canopy with gap creation by the felling of tree individuals or small groups of trees. In this analysis we concentrated on the variables concerning the stand composition and structure and the amount of dead wood.

As expected, the number and the amount of the dominant sessile oak (Q. petraea) has decreased significantly (from 393 stumps/ha to 337 stumps/ha; p-value<0.05 and from 23.5 m2/ha to 21 m2/ha; p-value<0.05) as a result of the treatment. Thus, the proportion of species shifted in favour of non-dominant tree species. Furthermore, the amount of standing and lying dead wood has greatly increased, the total amount of deadwood tripled (from 11.7 m3/ha to 34 m3/ha; p-value<0.05).

In conclusion, it is clear that conservation management succeeded in increasing the proportion of non-dominant species. Although, this increase is small now, compositionally much more heterogeneous stand is expected in the future as a result of the natural regeneration processes and due to further active management actions favouring the samplings of admixing species. The treatment contributed greatly to raise the amount of dead wood in the area. In the future we plan to continue the monitoring and analysis of the canopy layer and also to detect changes in the shrub layer and understory vegetation.