Journal of Forest Science, 2021 (vol. 67), issue 5

Determination of standards of raw timber natural losses due to shrinkage at long-term dry storageOriginal Paper

Dalibor Šafařík, Petra Hlaváčková, David Březina

J. For. Sci., 2021, 67(5):195-203 | DOI: 10.17221/83/2020-JFS  

The aim of the article is to describe the issue of determining the characteristics and parameters of raw timber natural losses due to shrinkage at long-term storage, defining the theoretical basis for creating standards, and verify its finding by means of a case study in raw timber storing. This issue is very topical in forestry practice in the Czech Republic as well as in other countries. The lower and upper limits of the standards were calculated, and the proposed mean value was grouped according to woody plants that reflected the most frequent commercial usage with respect to subsequent processing. Subsequently, experimental verification was carried...

Possibilities of forest property insurance against the risk of fire in SlovakiaOriginal Paper

Michaela Korená Hillayová, Klára Báliková, Blanka Giertliová, Josef Drábek, Ján Holécy

J. For. Sci., 2021, 67(5):204-211 | DOI: 10.17221/199/2020-JFS  

Fire is considered one of the major natural hazards that damages European forests and causes losses for forest owner. The forest fires endanger the financial stability of forest enterprises, which may cause their economic decline. One possibility how to cover these losses is to insure forest land against this kind of specific risk of forest land management. The aim of the present paper is to analyse possibilities of forest fire insurance for forest owners and enterprises in the Slovak private insurance market. The market analysis was based on document analysis of general terms and insurance conditions of chosen private insurance companies and interviews...

Improving the quality of sorting wood chips by scanning and machine vision technologyOriginal Paper

Igor Grigorev, Anatoly Shadrin, Sergey Katkov, Vyacheslav Borisov, Varvara Druzyanova, Irina Gnatovskaya, Roman Diev, Natalya Kaznacheeva, Dmitry Levushkin, Dmitriy Akinin

J. For. Sci., 2021, 67(5):212-218 | DOI: 10.17221/10/2020-JFS  

Improving the quality of sorting wood waste is the main problem in the timber industry from the point of view of saving energy resources and preserving the environment, associated with the intensity of forest harvesting. Depending on the required quality characteristics, the sorting of wood chips makes it possible to determine their further use in production or utilization as a fuel. This paper presents the results of the development of a novel approach to sorting wood chips on a conveyor belt using machine learning and scanning technology. The proposed methodology includes functions to analyze the fractional size distribution among wood chips and...

Diversity and degradation of the vegetation of mountain belt forests of central Adjara (the Lesser Caucasus), GeorgiaOriginal Paper

Nana Goginashvili, Natalia Togonidze, Irina Tvauri, Zurab Manvelidze, Nino Memiadze, Stefan Zerbe, Zezva Asanidze

J. For. Sci., 2021, 67(5):219-241 | DOI: 10.17221/80/2020-JFS  

The Colchis forests contribute to the biodiversity hotspot in the Caucasus eco-region. We investigated the plant diversity of these forests in the central part of Adjara (W Georgia). The aims of our study were (i) to differentiate the forest vegetation diversity in the mountain belt forests by means of phytosociology, (ii) to associate endemic taxa with the revealed forest types, and (iii) to assess degradation of the forest vegetation diversity by means of environmental abiotic and biotic factors. We sampled the forest vegetation on 135 plots with the size of 10 × 10 m2 and 237 plant taxa were recorded. Principal Component Analysis (PCA) was used...

Mechanized tree planting in Nordic forestry: simulating a machine concept for continuously advancing site preparation and plantingShort Communication

Jussi Manner, Back Tomas Ersson

J. For. Sci., 2021, 67(5):242-246 | DOI: 10.17221/203/2020-JFS  

As labour for manual tree planting becomes scarcer, regeneration costs are steadily increasing in Nordic forestry. Today's intermittently advancing tree planting machines provide excellent silvicultural results, but are expensive to operate because of poor productivity. In contrast, continuously advancing planting machines, thanks to high productivities, are increasingly being regarded as a solution to these runaway regeneration costs. The Silva Nova was a historical, continuously advancing tree planting machine with high productivity. However, Silva Nova's weaknesses included high labour costs (it required two operators) and the random nature of how...