A giant tree stand in the West Carpathians—An exception or a relic of formerly widespread mountain European forests?

Abstract

In Europe, remnants of formerly widespread natural mixed forests are rare. We analyzed an exceptionally tall tree stand with a very high wood volume in Hrončokovský grúň reserve, covering 55.2 ha in Slovenské Rudohorie Mountains in central Slovakia (48°43′N and 19°35′E) between 730 and 1050 m a.s.l. We compared our data to other natural stands to see if the growing stock and tree height were higher in Hrončokovský grúň. Fifty-four circular plots of 0.05 ha each and spaced at 100 m × 100 m distance sampled the entire reserve. Within each plot, live and dead trees were measured. Number, basal area and volume of live trees and volume of CWD were calculated. Moreover, measurements of the tallest trees were conducted in the whole reserve area. Total volume of live trees and CWD in the studied reserve was 1030 m 3 per hectare. It is the second highest value ever recorded in an area of several hectares or larger in European forests. The feature that makes the stand in Hrončokovský grúň a unique one is the height of trees. In the whole reserve, about 600 trees exceeded the height of 45 m. Individuals of three deciduous species ( Acer pseudoplatanus, Fraxinus excelsior, Ulmus glabra) are the tallest ones found in unmanaged forests in the whole Europe. Those of Fagus sylvatica reached height near the maximum value ever recorded. In Europe, stands of average total live and dead wood volume above 1000 m 3 ha −1 with numerous trees above 40 m tall were probably very rare even several centuries ago, when virgin forests were widespread. Most likely, they were confined to rather small mountain areas, where rich soils supporting high stand productivity occurred along with wind-protected slopes, where natural disturbances were rare and stand turnover rate was low.