Young Silver Birch Grows Faster and Allocates Higher Portion of Biomass into Stem Than Norway Spruce, a Case Study from a Post-Disturbance Forest

Bohdan Konôpka,Jozef Pajtík,Katarína Merganičová,Peter Surový,Vladimír Šebeň

doi:10.3390/f12040433

Abstract

The aim of the paper was to compare young silver birch (Betula pendula Roth.) and Norway spruce (Picea abies L. Karst) growing at the identical site, from the point of contribution of tree components to their aboveground biomass stock, their wood density, radial increment and aboveground biomass production. Our research activities were performed in the High Tatra Mts., which belong to the Tatra National Park (TANAP), Northern Slovakia. Currently, the substantial part of the TANAP territory is covered by post-disturbance young forests which have been growing there since the large-scale windstorm episode in November 2004. Our study combined non-destructive repeated tree measurements performed at two transects in 2016–2020, with destructive tree sampling of twenty 14-year-old individuals for each species. From the gathered data, we derived models estimating standing stock and annual production of aboveground biomass in individual tree components (foliage, branches, stem bark and stem wood), using diameter at breast height (DBH) as a predictor. The results showed contrasting contributions of tree compartments to aboveground biomass stock between birch and spruce. While spruce trees had four times higher contribution of foliage than birches, the reverse situation (1.5-fold difference) was observed for stem over bark biomass. At the same time, birch trees had a 40% greater diameter increment and a 30% denser stem wood than spruce. As for aboveground biomass production, the contribution of the stem as an economically important component was greater in birch than spruce. The results suggest that, in the young growth stage, birch may be advantageous over spruce in both ecological and production properties. Therefore, we believe that strengthening research activities focused on birch ecology and production issues would bring practical recommendations for better utilization of this tree species in forestry and wood-processing industry sectors

Highlights

IntroductionWindstorms cause serious damages to forests in most European countries, especially in Western, Central and Northern Europe [1]
The results indicated that 14-year-old birch trees produced annually slightly more aboveground biomass than the spruce trees of the same age with the same diameter at breast height (DBH) (Figure 7a)
Silver birch is typical with fast growth and great production potential, its vitality and vigorous growth is sustained only if it grows as dominant trees in a stand with a relatively wide spacing [19]

Summary

Introduction

Windstorms cause serious damages to forests in most European countries, especially in Western, Central and Northern Europe [1]. Carpathians (mostly situated in Slovakia), where the area of damaged forests by windstorms accompanied by bark beetle outbreaks has a gradually increasing tendency especially since the beginning of the new millennium [2]. The main consequence of recent windstorm disturbances is the increasing windthrown area, later covered by young forests. This is the principal reason why current scientific attention should focus on post-disturbance areas and forest development to a larger extent than in the past

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