Productivity differences between southern and northern slopes of Southern Carpathians (Romania) for Norway spruce, silver fir, birch and black alder

Lucian DINCĂ,Voichița TIMIȘ-GÂNSAC,Cristian M. ENESCU,Liviu HOLONEC,Lucian GEORGESCU,Gabriel MURARIU,Florin ACHIM,Adrian MURARIU

doi:10.15835/nbha48211824

Abstract

Forest vegetation across Southern Carpathians is distributed in altitudinal layers. The aim of this study was to highlight the productivity differences between the Southern and Northern slopes of the Southern Carpathians for Norway spruce, silver fir, birch and black alder. Data from 45 forest management plans (46.329 stands from the Southern slopes and 32.787 stands from the Northern slopes) were used. For each stand, the mean diameter, mean height, age, standing volume, current volume increment and production class were assessed. Elementary statistical methods were used to identify the factors influencing productivity. Significant differences between the Southern and Northern slopes were recorded for silver fir. The volume and the current volume increment were higher on the Northern slopes. In the case of birch and black alder, the same two parameters recorded higher values on the Southern slopes. As regards Norway spruce, insignificant differences were recorded between the two slopes. The correlation between structure type and stand volume was positive and statistically significant in the case of Norway spruce, silver fir and birch, but it was negative in the case of alder. Analysing the correlation between stand volume and the main stand characteristics also revealed a statistically significant positive correlation between age and stand volume for all analysed species. The results of this study are especially interested for the forest managers and forest owners whose aim is to obtain a higher productivity for the studied species.

Highlights

Carpathians account for a total area of 158.000 km2, of which 52.9% is distributed across Romania
Since four fifths of the total forested area of Southern Carpathians are represented by two species, namely Norway spruce and common beech, on one hand, and by taking into account the higher productivity recorded for silver fir on the northern side and the insignificant difference between the two slopes in the case of Norway spruce’s productivity, on another hand, future forest planning measures should increase the share of silver fir in the mixed forests or even in pure Norway spruce forests across northern side of Southern Carpathians
Introducing silver fir in various shares in pure Norway spruce forests will increase their stability against windfalls

Summary

Introduction

Carpathians account for a total area of 158.000 km, of which 52.9% is distributed across Romania. Located in the south of the Transylvanian Depression, they are bordered on the east by Prahova Valley and on the west by Timiş-Cerna Corridor (Figure 1). This mountain range includes the highest peaks in Romania: Moldoveanu (2.544 m a.s.l.) and Negoiu (2.535 m a.s.l.), both situated in Făgăraș Mountains, and Parâng (2.519 m a.s.l.), Retezat (2.509 m a.s.l.) and Bucegi (2.505 m a.s.l.). The mean air temperature ranges from +7°C to -2°C at altitudes of over 2100 m a.s.l. Rainfalls are influenced by the relief, with significant differences between the western and north-western slopes as well as between the eastern and south-eastern slopes. Rainfalls are heavier on the north-western slopes, recording average values of 800 mm/year on the southern border and approximately 1200 mm at higher elevations (Mihai et al, 2007)

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Conclusion