Modelling the distribution of diameter growth along the stem in Scots pine

• Published in: Trees (Berlin, West) West), 2006-05, Vol.20 (3), p.391-402
• Main Authors: Ikonen, V.P, Kellomäki, S, Väisänen, H, Peltola, H
• Format: Article
• Language: English
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; conifers; Economic plant physiology; equations; Evergreen trees; forest thinning; forest trees; Fundamental and applied biological sciences. Psychology; Growth and development; mathematical models; Morphogenesis, differentiation, rhizogenesis, tuberization. Senescence; Pine trees; Pinus sylvestris; simulation models; spatial distribution; stand density; stand management; statistical analysis; stem form; stems; Studies; tree and stand measurements; tree growth; Trees
• ISSN: 0931-1890; 1432-2285
• DOI: 10.1007/s00468-006-0053-7

This paper presents an empirical model for the distribution of diameter growth along the stem in Scots pine (Pinus sylvestris L.) and for the consequent stem form over time. First, the distribution of annual mass growth in the stem is determined as a function of the total annual growth in stem mass, current stem mass and the distribution of the latter along the stem. Second, the distribution of diameter growth is obtained by converting the fraction of annual growth in the stem mass at a given height in the stem into the thickness of the annual ring at the same height. Application of the model to Scots pine data sets including both young and mature trees not used in parameter estimation showed that the model was capable of reconstructing the distribution of diameter growth from the stem butt to the apex and from the pith to the stem surface at any height in the stem in both young and mature trees. The resulting empirical model was also linked to a physiological, process-based model in order to study its performance in a simulated stand. Simulations representing trees grown in unthinned and thinned Scots pine stands with trees of different status (from dominant to suppressed) showed that the response in tree growth to thinning in terms of the distribution of diameter growth along the stem was quite realistic relative to measured data.[PUBLICATION ABSTRACT]