Journal of Forest Science, 2023 (vol. 69), issue 12
Development of Douglas fir merchantable stem volume model in the conditions of the Czech RepublicOriginal Paper
Radoslav Hlavica, Zdenìk Adamec
J. For. Sci., 2023, 69(12):515-524 | DOI: 10.17221/92/2023-JFS 
A precise merchantable stem volume model of Douglas fir [Pseudotsuga menziesii (Mirb.) Franco] is missing in the Czech Republic. The aim of this study was to fit a new model through the reparametrization of volume equations (used in the Czech Republic or in other countries). We tested four volume equations (two from the Czech Republic, one from France and one from British Columbia) in the form of a nonlinear least squares model (NLS), weighted least squares model (WLS), and nonlinear mixed effects model (NLME). In all the tested models, the diameter at breast height of a tree and the total height of a tree were used as independent variables....
Thinning effects on growth and occurrence of rotting in aspen standsOriginal Paper
Alina Nasibullina, Marieke van der Maaten-Theunissen, Ernst van der Maaten, Holger Fischer, Sven Wagner
J. For. Sci., 2023, 69(12):525-538 | DOI: 10.17221/103/2023-JFS
Poplar species such as aspen (Populus tremula L.) play a very important role in the forest formation process not only in Eastern European regions. Unfortunately, such aspen stands are often severely affected by fungal diseases, causing mainly core rot. In this study, the indirect effects of thinning on the phytosanitary condition of aspen by promotion of tree growth were investigated. Two thinning methods, manual (thinning from below) and mechanical thinning (schematic), were applied to young stands dominated by Eurasian aspen to study their effects on tree growth and health. All trees were measured at breast height and diameter frequency...
Understanding the role of ecotypic factors in the early growth of Pinus sylvestris L.Original Paper
Jakub Hejtmánek, Jan Stejskal, Daniel Provazník, Jaroslav Èepl
J. For. Sci., 2023, 69(12):539-549 | DOI: 10.17221/102/2023-JFS
The ecological significance of Scots pine (Pinus sylvestris L.) in Europe, especially in areas devastated by bark beetles, has led to its consideration as a substitute for Norway spruce. This pioneering species boasts sun and drought tolerance, fast growth, and wood industry value. To gauge its potential, we examined two ecotypes across two test sites over two years, focusing on height and growth increment. Through statistical analysis employing R software and linear mixed models, we assessed heritability, genotype by environment interaction, and spatial correlations. Both ecotypes exhibited significant differences in height and increment, varying...
Stand structure of a juvenile Paulownia Shan Tong plantation grown in the temperate dry climate zone in Hungary – A case studyShort Communication
Fruzsina Szabó, Károly Rédei, Tamás Ábri, Elza Kovács, Lajos Juhász
J. For. Sci., 2023, 69(12):550-556 | DOI: 10.17221/90/2023-JFS
In this paper, empirical relationships between diameter at breast height (DBH), crown diameter (CD), and stem number per hectare (N) were improved in a Paulownia Shan Tong plantation. Various functions of these variables were defined, focusing on growing space (Gs) and stem number per hectare. The linear crown index between CD and DBH seems to be particularly important in predicting stem number per hectare. Based on an analysis of the relationships, a CD-DBH (R2 = 0.7254) and a DBH-N graphic model (R2 = 0.7302) can be applied...