Forest Regeneration Patterns Differ Considerably between Sites with and without Windthrow Wood Logging in the High Tatra Mountains

Bohdan Konôpka,Vladimír Šebeň,Katarína Merganičová

doi:10.3390/f12101349

Abstract

Our research focused on the impact of post-disturbance management on the subsequent forest stands in the territory of the High Tatra Mts. situated in the northern part of Slovakia. The field work was carried out within the post-disturbance area in 2019, i.e., 15 years after the windstorm. In total, we used data from 80 monitoring plots (MP): 40 plots situated inside the managed part and 40 in the unmanaged areas. Post-disturbance management specifically consisted of logging of wind-thrown wood; therefore, the main difference between the two areas (salvaged versus unsalvaged) was the amount of coarse woody debris (CWD) left on site. We focused on the characteristics of newly regenerated forest stands: the number of trees and tree species per MP, tree height and browsing (mostly by red deer, Cervus elaphus) were recorded as was their growth substrate, i.e., soil or CWD. Higher tree densities, larger trees as well as higher tree species richness were found at salvaged plots. In addition, more evident dominance of Norway spruce (Picea abies (L) Karst.) was recorded at unsalvaged plots. Common rowans (Sorbus aucuparia L.) were frequent at both plot types. Birch trees (Betula sp.) were very frequent at salvaged plots, while only a few birch individuals were recorded at unsalvaged ones. The proportion of trees growing on CWD was 15% at unsalvaged and 3% at salvaged plots. Trees growing on the soil contained nearly double the aboveground biomass than those on CWD. Red deer browsing was approximately two times more frequent at salvaged than unsalvaged plots. While rowan was extremely prone to browsing, spruce was damaged negligibly. These main findings could have two contradictory conclusions, the positive one being that differentiated post-disturbance management within a certain area can combine both forestry and nature conservation interests. Moreover, it can generate parallel forests with different properties that might positively influence the future stability of forest ecosystems as a whole. The negative side might be that contrasting post-disturbance management can cause an uneven distribution of red deer population and intensive browsing in areas favourable for game.

Highlights

A study on post-disturbance forest development after these windstorm episodes proved a close interaction between wind and bark beetle damage in forests, which is amplified by ongoing climate change [5]
Because of relatively high altitudes, the climate is typically cold and moist, and snow cover lasts around 120 days [14]
3037 trees were recorded and measured at all monitoring plots (MP), while 1834 individuals were found at salvaged MPs and 1203 individuals at unsalvaged MPs

Summary

Introduction

In the prevailing part of boreal and temperate forests in Europe, large-scale disturbances have been occurring with an increasing tendency over the last two to three decades [1]. The increasing contribution of wind to the total volume of disturbed wood has been observed, especially in Central, Northern and Western Europe [2]. The largest and most destructive storms in Central Europe were “Kyril” (17–19 Janury 2007) and “Emma” (28 February–2 March 2008), which damaged large areas of forests, especially in Germany and Czechia [3]. The storm caused forest destruction equalling nearly 200 million m3 of wood [4]. A study on post-disturbance forest development after these windstorm episodes proved a close interaction between wind and bark beetle damage in forests, which is amplified by ongoing climate change [5]

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