Epsilon Archive for Student Projects

Abstract

Dendrometer measurements provide a non-destructive method for monitoring stem growth, whereas tree-ring analysis represents a traditional but destructive approach commonly used in dendrochronology. This study assessed the relationship between dendrometer-derived basal area increment (BAID) and tree-ring-derived basal area increment (BAITR) along the trunk of Norway spruce (Picea abies) and investigated whether root rot affects this relationship. The study was conducted at the Asa Research Station in southern Sweden, where 10 Norway spruce trees were selected from two plots, one of which was affected by root rot. Stem diameter measurements taken at breast height (1.3 m) using dendrometers to determine annual basal area increment (BAID) and compared with tree-ring-derived basal area increment (BAITR) at various heights along the stem (Base, 1.3 m, 4 m, 8 m, 12 m, 16 m, 20 m and 24 m). The results showed positive correlations between BAID and BAITR, with the strongest correlation observed at breast height (Pearson’s r = 0.891). Model performance generally declined with increasing tree height, with the weakest correlations observed at 24 m. Including root rot as a factor slightly improved model fit, although this effect was not statistically significant. The results indicate that dendrometer measurements taken at breast height provide reliable estimates of overall annual stem growth in Norway spruce, particularly at lower stem positions. However, growth patterns become increasingly variable with increasing height. This study demonstrates the potential of the dendrometer as a non-destructive tool for long-term forest growth monitoring, whilst also highlighting the importance of accounting for vertical variation within the stem and root rot.