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Research article - Peer-reviewed, 2022

Effect of Aspect-Slope on the Growth of Conifers in a Harsh Boreal Climate of Northwest Sweden

Ogana, Friday N.; Sjodin, Fredrik; Holmstrom, Emma; Fries, Clas; Nilsson, Urban;

Abstract

Tree development is affected by different factors including topographic features. The effect could be even more complex in harsh environments such as in the northwest of Sweden. In this study, we analyzed the effect of aspect-slope on the development up to the age of 34 years of five species: black spruce, lodgepole pine, Norway spruce, Siberian larch and Scots pine. The species were planted in a field experiment on the southwest slope, mountaintop, and northeast slope in a randomized complete block design in the northwest of Sweden (latitude 67 degrees) with 2 m x 2 m spacing. No re-measurement data were available and, as such, retrospective diameters and heights were derived from sample discs and measurement of length to every branch whorl, respectively. Variations in tree survival rate, height and diameter were analyzed using a linear mixed-effect model. The results showed that there were significant (p < 0.05) differences between species in survival rate, diameter and height growth; in some cases, differences were found between contrasting aspect-slope. Black spruce and Siberian larch had the best survival rate under this harsh boreal climate. However, Siberian larch had the best growth and developed well on the mountaintop and northeast slope. Lodgepole pine developed well on the southwest slope. Scots pine also grew well on the southwest slope and mountaintop. Norway spruce had the slowest growth. Based on this study, Siberian larch and lodgepole pine can serve as alternatives to the two traditional conifer species, Norway spruce and Scots pine, used in Sweden. Siberian larch is particularly suitable because it is able to withstand the harshness of the boreal environment.

Keywords

Siberian larch; lodgepole pine; Scots pine; Norway spruce; black spruce; diameter and height growth; survival; harsh boreal climate

Published in

Forests

2022, volume: 13, number: 2, article number: 301
Publisher: MDPI

Authors' information

Ogana, Friday Nwabueze
Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre
Swedish University of Agricultural Sciences, Unit for Field-based Forest Research
Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre
Fries, Clas
Swedish Forest Agency
Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre

UKÄ Subject classification

Forest Science

Publication Identifiers

DOI: https://doi.org/10.3390/f13020301

URI (permanent link to this page)

https://res.slu.se/id/publ/119098