Journal of Forest Science - Latest articles

Environmental problems and biodiversity conservation through silviculture in Sri Lanka: Current state, struggles and cooperation with Czech foresters – A review

Channa Suraweera, Josef Gallo, Stanislav Vacek, Martin Baláš

J. For. Sci., 2024, 70(6):281-298 | DOI: 10.17221/19/2024-JFS  

Sri Lanka, as a developing tropical country, faces serious environmental challenges. Forests, as important ecosystems of Sri Lanka, are under pressure from intensive human activities and climate change. Invasive species represent a great hazard to autochthonous plant species and ecosystems, which are, at the same time, hosts to extraordinarily high biodiversity, of which a high percentage is endemic. In this paper, we reviewed the most challenging environmental problems of Sri Lanka and suggested the improvement of a number of them through silvicultural measures and cooperation with international experts, namely Czech foresters. We also reviewed the...

Evaluation of the effect of different thinning types on dendrometric parameters and subsequent spontaneous growth in a beech-oak-linden stand

Kateřina Novosadová, Jiří Kadlec, Petr Sýkora, Martin Kománek, Radek Pokorný

J. For. Sci., 2024, 70(6):299-316 | DOI: 10.17221/10/2024-JFS  

Due to an increasing risk of further damage to forests, forest managers are considering introducing an alternative direction for their future development – via the cultivation of mixed forests. At middle altitudes in the Czech Republic, an oak-beech-linden stand is the most natural type, and we tried to answer three main questions: (i) How the various thinning types affect dendrometric parameters and quality of the stand; (ii) How long thinning works on this stand until it loses its effect; (iii) How the stand develops spontaneously after abandonment. This experiment was conducted at the Training Forest Enterprise in the...

Overgrazing strongly impedes the natural regeneration of the endemic Boswellia species on Socotra Island

Salem Hamdiah, Klemen Eler, Kay Van Damme, Fabio Attorre, Dario La Montagna, Michele De Sanctis, Mohammed Shaneyehen, Mohammed Amar, Theodore Danso Marfo, Petr Maděra

J. For. Sci., 2024, 70(5):249-263 | DOI: 10.17221/3/2024-JFS  

Frankincense trees (Boswellia spp.) worldwide are affected by a number of threats, including global warming and changing land management practices. On the Socotra Archipelago (Yemen), which harbours eleven endemic Boswellia species, grazing is generally assumed to be one of the main threats preventing natural regeneration. To test the impact of overgrazing on natural regeneration, we established an in situ experiment on four different Boswellia taxa in different areas of Socotra Island. Mortality and the height increment of seedlings were measured for a period of two/three years in five plots excluded from grazing (fenced)...

Innovations in the methodological approach to quantifying and evaluating the supported effects of forests for recreational and educational ecosystem services

Zdeněk Odvárka, Jitka Meňházová

J. For. Sci., 2024, 70(5):235-248 | DOI: 10.17221/13/2024-JFS  

The paper deals with a new method of innovative assessment of the supported effects and ecosystem services of forests using the actual amount of their increased costs. Among the most important research findings and significance of the new method is that it contributes to the body of knowledge on valuation and payment for ecosystem services. The focus of the research task is to help address the current difficult economic situation of forest owners resulting from the impacts of climate change. The study aims to determine what work quantifies the amount of compensation for the provision of supported ecosystem services that is sufficient for owners by...

Tree resources decline in Saudi Arabia: Climate change or pest attack causes?

Naimah Alanazi

J. For. Sci., 2024, 70(5):223-234 | DOI: 10.17221/9/2024-JFS  

In Saudi Arabia, tree mortality has abnormally increased over the past ten years, exceeding regulatory standards without clear interpretation. The present study aimed to investigate three attacked tree populations in different biogeographic regions of Saudi Arabia. For this purpose, climatic data from the last thirty years, forest densities, soil cover, pest search, and insect damage to trees have been reported. The results of this study show a distinct climate change manifested by an increase of 2 °C in temperature accompanied by a decrease in precipitation and the extension of drought periods during the last 30 years. Analysis of satellite...

Sensitivity analysis and performance evaluation of neural networks for predicting forest stand volume – A case study: District 2, Kacha, Guilan province, Iran

Sima Lotfi Asl, Iraj Hassanzad Navroodi, Aman Mohammad Kalteh

J. For. Sci., 2024, 70(5):209-222 | DOI: 10.17221/111/2023-JFS  

Tree volume is a characteristic used in many cases, such as determining fertility, habitat quality, growth size, allowable harvesting, and the principles of forest trade. It is imperative to develop methods that predict forest stand volume to obtain this extensive information quickly and cost-effectively. This study used supervised self-organising map (SSOM), multi-layer perceptron (MLP), and radial basis function (RBF) neural networks to predict forest stand volume based on physiography, topography, soil, and human factors. A sensitivity analysis method called the importance of prediction was used to determine how input variables influenced network...

Effects of slope and tree position on soil properties in a temperate deciduous forest

Gabriela Tomášová, Tomáš Vichta, Nikola Žižlavská, Jan Deutscher, Ondřej Hemr, Martina Brychtová, Lenka Pavlů, Aleš Bajer

J. For. Sci., 2024, 70(4):185-201 | DOI: 10.17221/117/2023-JFS  

This paper examines changes in soil physical and chemical properties in relation to tree proximity on different slopes. Topsoil and subsoil were sampled at 12 research plots on four slope types, the soil pits being placed at the base of a tree (near tree, NT) and between the test tree and an adjacent tree (between trees, BT). We observed a significant decrease in vertical topsoil response to slope on lower, middle and upper slopes, and a decrease in fine roots (R < 2 mm) on flat ground. Overall, middle and lower slopes showed the highest similarity, and upper slopes and flat ground the least, with the greatest subsoil...

Light response curve analysis of juvenile black locust clones: A case study from eastern Hungary

Tamás Ábri, Dániel Gaganetz, József Csajbók

J. For. Sci., 2024, 70(4):202-207 | DOI: 10.17221/120/2023-JFS  

Assimilation (A) and photosystem II (PSII) efficiency value light response curves [A/PPFD and PSII/PPFD curves (PPFD – photosynthetic photon flux density)] of promising black locust clones (NK2 and PL251) and the registered Üllői clone were analysed to study the net assimilation rates and PSII efficiency within the function of PPFD levels. The natural logarithmic regression functions fitted well to the measured data points for A/PPFD, R² values varied between 0.9515–0.9884. For PSII/PPFD values, we used the exponential regression...

Old Juniper Troll stand – The oldest shrub population from Scandinavia

Jiří Lehejček, Matěj Roman, Martin Lexa, Paul Eric Aspholm, Jiří Mašek

J. For. Sci., 2024, 70(4):176-184 | DOI: 10.17221/118/2023-JFS  

Old plant communities are of utmost importance for nature conservation, carbon sequestration, as well as gene pool maintenance. Shrub populations occurring in extreme environments beyond abiotic tree-lines provide diverse ecosystem services and have potential as proxy archives because they often inhabit areas with scarce and short instrumental records. We provide dendrochronological insight into one such population made up of prostrate Juniperus communis shrubs in the northern Scandinavian tundra (Norway), growing on a competition-free boulder field. We dated and provided a growth chronology of the oldest living shrub population (190 ±...

Nutrient content in biomass of bilberry (Vaccinium myrtillus L.) in different habitats of protected areas of Inner Western Carpathians

Martin Kubov, Rastislav Janík, Jakub Tomes, Branislav Schieber

J. For. Sci., 2024, 70(4):161-175 | DOI: 10.17221/110/2023-JFS  

The primary objective of this paper was to compare the nutrient content (N, Ca, S, K, P, Mg) of bilberry biomass, both aboveground and underground, growing in different habitats along the altitudinal gradient. The research was conducted in protected areas of the High Tatras National Park (Slovakia). Two different habitats subjected to study, namely spruce forest stands affected by disturbances (D – disturbed forest stands) and stands unaffected by disturbances (U – undisturbed forest stands), were located at different altitudes: 1 100 m a.s.l., 1 250 m a.s.l., and 1 400 m a.s.l. We found significant differences...

Calculation and operational assessment of tyre contact areas in the tractor-and-trailer unit

Milan Marušiak, Tomáš Zemánek, Jindřich Neruda, Pavel Nevrkla

J. For. Sci., 2024, 70(3):144-159 | DOI: 10.17221/109/2023-JFS  

This paper deals with the verification of models for the calculation of the contact area with the soil using data measured during the testing of a tractor-and-trailer unit. The main emphasis was put on the method of calculating the contact area by means of a super ellipse. The comparison included calculation models with the input parameters of contact length and contact width of the tyre. These parameters were compared with values measured in the field where the main variables were tyre dimensions, inflation pressure and load. Results of comparisons show that the method of calculating the contact area using a super ellipse exhibited the best match...

Use of the threshold segmentation method as an alternative for estimating the volume of forest industry residues

Carlos Borrego-Núñez, Pablito Marcelo López-Serrano, Pedro Antonio Domínguez-Calleros, Jorge Luis Compeán-Aguirre, Artemio Carrillo-Parra

J. For. Sci., 2024, 70(3):135-143 | DOI: 10.17221/105/2023-JFS  

In recent decades, the interest in searching for procedures and strategies to make energetic and economic use of residues from different industries has been an important part of the political agenda. There are several methods to determine the volume of residues from the forestry industry, but they are too time-consuming to apply. The objective of the present study was to establish a simpler and more efficient method to quantify the volume of residues from the forest industry. Ten controlled piles were made with residues from a private sawmill in the city of Durango, Mexico. To calculate the volume, two manual methods and one automatic method were used...

Detecting land use/land cover changes and forest degradation: A case study of the lower Soummam valley, northern Algeria

Megdouda Smail, Zoubir Boubaker, Mohamed Sbabdji, Habib Mouaissa, Bimare Kombate

J. For. Sci., 2024, 70(3):122-134 | DOI: 10.17221/86/2023-JFS  

The environment is characterised by subtle and major mutations that cause changes in land use/land cover. Analysis of its dynamics and identification of vulnerable areas are critical to maintaining ecosystem services. The aim of this research is to quantify and qualify land cover dynamics over a 30-year period. It will also highlight forest degradation from a supervised classification of Landsat satellite imagery (L5 TM1987, L7 ETM+ 2000, and L8 OLI/TIRS 2019). The dynamics of land use/land cover were investigated by a maximum likelihood approach using geographic information system (GIS) and remote sensing (RS). Six major land use and land cover (LULC)...

Chemical forest amelioration: Experience from the Czech Republic and other selected countries – A review

Martin Baláš, Ivan Kuneš, Vilém Podrázský, Josef Gallo, František Lopot

J. For. Sci., 2024, 70(3):103-121 | DOI: 10.17221/72/2023-JFS  

This review article summarises the results of research on forest liming, fertilisation, nutrition flows and cycles in selected European and other countries. The presented studies mostly deal with assessing the effect of liming and fertilisation applied during planting or shortly after planting. The sporadic studies on fertilisation in older stands are also presented. The application of crushed limestone, dolomite or other alkaline rocks or their mixtures is usually used to improve the soil conditions on a large area through the adjustment of soil acidity and to supply any deficient elements, especially calcium and magnesium. These amendments are typically...

Applying the European Union (EU) assessment initiative of forest sustainability in Africa: A case study of the timber harvesting impact on the environment in Sierra Leone

Petra Hlaváčková, Sheku Kemoh Mansaray, Samuel Antwi Darkwah, Iva Živělová

J. For. Sci., 2024, 70(2):79-90 | DOI: 10.17221/74/2023-JFS  

The European Union (EU) provides both financial and expert support for sustainable forest management initiatives and also boosts compliance with such initiatives in Africa. Thus, there is a need to monitor the progress of implementing such initiatives. The objective of this paper is to describe the role of timber harvesting entities in environmental impact discussions, and to also identify the role of EU institutions in promoting forest sustainability in Sierra Leone. Data were collected in a controlled survey from four communities, using a questionnaire formulated according to guidelines recommended by Babbie and Mouton (2010). The reliability test...

Water content in soil afforested with a mixture of broadleaves or Scots pine

Jan Vopravil, Pavel Formánek, Tomáš Khel, Karel Jacko

J. For. Sci., 2024, 70(2):91-101 | DOI: 10.17221/114/2023-JFS  

Afforestation of agriculturally used land has many benefits which are described in different publications. As stated in these publications, afforestation of agricultural land can influence soil water content because of rainfall interception and concentration, transpiration, and properties of forest floor layer and soil; also, hydraulic lift may occur. In this study, we attempted to find changes in volumetric soil water content values (at depths of 20 cm, 40 cm, and 60 cm) on agriculturally used land afforested with a mixture of forest tree species (Quercus robur L., Quercus rubra L., and Acer platanoides L.)...

Comparison of growth, structure and production in stands of naturally regenerated Betula pendula and Populus tremula

Antonín Martiník, Zdeňek Adamec, Matúš Sendecký, Jan Krejza

J. For. Sci., 2024, 70(2):64-78 | DOI: 10.17221/107/2023-JFS  

In Central Europe, the most important pioneer species are silver birch and European aspen. Changes in disturbance regime and an economic interest for this species have led to studies on this species and stands. Two naturally regenerated dense stands of birch (Betula pendula Roth – silver birch monoculture) and aspen (Populus tremula L. – European aspen monoculture) were selected from a Querceto – Fagetum mesotrophicum site to observe responses under the same conditions in Central Europe. Both stands regenerated after the allochthonous Norway spruce stands dieback at the site in 1999. Within a 10 m × 25 m...

Administrative system of afforestation in the Czech Republic: A long journey to a new forest

Martin Baláš, Josef Gallo, Marcin Czacharowski, Michal Pástor, Jaroslav Jankovič, Igor Štefančík, Ivan Kuneš, Hubert Hasenauer

J. For. Sci., 2024, 70(2):41-63 | DOI: 10.17221/75/2023-JFS  

This review uses a case study based on an executed afforestation project to comprehensively describe the administrative procedure regarding afforestation of agricultural land in the Czech Republic, Central Europe. We consider the official proceedings for obtaining a permit to land-use change (i.e. changing the nature of land use and the mode of land use in the real estate cadastre) as a very complex and protracted procedure, which can substantially reduce the motivation of people to establish new forests. Therefore, we propose a simplification of the administration process of land-use change. The main idea is to make the procedure as simple as possible...

Index of reviewers 2023

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J. For. Sci., 2024, 70(1):I  

Characteristics of powdery mildew [Sawadaea bicornis (Wallr.) Miyabe] influence on the photosynthetic process in Norway maple (Acer platanoides L.) seedlings

Anna Alexeyeva, Kyrylo Holoborodko, Iryna Ivanko, Olexandr Zhukov, Iryna Loza

J. For. Sci., 2024, 70(1):31-39 | DOI: 10.17221/30/2023-JFS  

The article presents the results of research on the impact of Sawadaea bicornis (Wallr.) Miyabe on the state of photosynthetic apparatus in Acer platanoides L. seedlings using a technique of chlorophyll fluorescence induction (ChlF) measurement, which at the present time can be implemented through the use of biosensors. The research was conducted in September 2022 in the territory of the Botanical Garden of Oles Honchar Dnipro National University. To diagnose a violation of the native chlorophyll photosynthesis in fresh leaves of A. platanoides, a portable fluorometer 'Floratest' was used (the selected spectral range for fluorescence...

Comparison of the growth of the provenances of silver fir (Abies alba Mill.) on research plots in the regions Novohradské hory and Českomoravská vrchovina at the age of 50 years

Jiří Čáp, Martin Fulín, František Beran, Jaroslav Dostál, Martina Komárková

J. For. Sci., 2024, 70(1):14-23 | DOI: 10.17221/113/2023-JFS  

The study evaluates the results of a long-term research trial lasting 50 years in two research plots established in the 1970s aimed at solving the decline of the silver fir in the Czech Republic. A total of 103 different provenances occurring naturally across 12 countries were planted in research plots No. 67, Černovice (Českomoravská vrchovina), and No. 77, Nové Hrady (Novohradské hory). The total tree height, diameter at breast height (DBH) and assessment of the health status of all trees in the area were measured with the same methodology. Subsequently, the volume of large wood was calculated by the volume equation, and the growing stock...

First records of Glyptapanteles liparidis (Braconidae, Microgastrinae) and Gelis areator (Ichneumonidae, Cryptinae) in Slovenia

Vladimir Žikić, Tanja Bohinc, Christos Athanassiou, Paraskevi Agrafioti, Matilde Eizaguirre, Drago Trajber, Stanislav Trdan

J. For. Sci., 2024, 70(1):24-30 | DOI: 10.17221/106/2023-JFS  

Lymantria dispar, a well-known defoliating pest species, also presents a health challenge due to the allergenic potential of its hairs, making it interesting to study from various perspectives. As chemical control methods decline in popularity, the search for effective natural enemies of this pest, such as predators, parasites and parasitoids, are expanding. On this occasion, we report the discovery of the primary parasitoid Glyptapanteles liparidis and the secondary parasitoid Gelis areator for the fauna of Slovenia. Illustrations and a short biology are given for both species.

Genetic diversity and phylogenetic analysis of Robinia pseudoacacia L. populations using ISSR markers, ITS1 and trnL-F intergenic spacer sequences

Mehmet Emin Uras, Ertugrul Filiz, Ugur Sen, Ibrahim Ilker Ozyigit

J. For. Sci., 2024, 70(1):1-13 | DOI: 10.17221/95/2023-JFS  

Robinia pseudoacacia L. is a deciduous tree planted almost all around the world for a wide variety of uses such as ornamental in urban ecosystems and forest trees in afforestation. This study aims to evaluate the genetic diversity and phylogenetic relations of R. pseudoacacia using some selected populations in Istanbul and Kocaeli cities. For this aim, molecular marker-assisted and DNA sequence-based analyses were performed. According to the results, nine of 15 inter simple sequence repeats (ISSR) primers gave clear and distinguishable bands with a total of 100 loci. The percentage of polymorphic loci (PPL) was calculated as 100%...

Understanding the role of ecotypic factors in the early growth of Pinus sylvestris L.

Jakub Hejtmánek, Jan Stejskal, Daniel Provazník, Jaroslav Čepl

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...

Thinning effects on growth and occurrence of rotting in aspen stands

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...

Development of Douglas fir merchantable stem volume model in the conditions of the Czech Republic

Radoslav Hlavica, Zdeněk 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....

Stand structure of a juvenile Paulownia Shan Tong plantation grown in the temperate dry climate zone in Hungary – A case study

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 (G_s) 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...

Modelling the tree height-diameter relationship of Macedonian pine (Pinus peuce Gris.) forests in North Macedonia

Vladimir Tanovski, Bratislav Matović, Mihajlo Risteski, Pande Trajkov

J. For. Sci., 2023, 69(11):497-513 | DOI: 10.17221/68/2023-JFS  

The most crucial individual tree variables in forest management are diameter at breast height (DBH) and height of trees (H). Projection of stand development over time relies on accurate height-diameter functions. The main aim of this paper is to define the best usable model for tree height prediction from diameter at breast height. We explore the place where the Macedonian pine was discovered in the Baba Mountain in the Pelister National Park in North Macedonia. Thus, we established 48 experimental plots (EP) with a circle shape, a radius of 12.62 m and an area of 500 m² each. The EP were established in pure Macedonian...

Potential of Morus nigra in Central Europe focused on micropropagation: A short review

Pavel Švagr, Josef Gallo, Jan Vítámvás, Vilém Podrázský, Martin Baláš

J. For. Sci., 2023, 69(11):463-469 | DOI: 10.17221/73/2023-JFS  

This paper is focused on the description of the black mulberry (Morus nigra), its ecology and the possibilities of its in vitro propagation for quick and efficient obtaining of a large quantity of clones in a relatively short time for subsequent planting or sale. Due to ongoing climate change, it is considerable to use mulberry trees in horticulture, agroforestry and forestry under the conditions of Central Europe. The use of the mulberry is conditioned by the availability of planting stock. A proven and successful method of mulberry propagation is in vitro cultivation. Based on literature review, the recommended composition of planting...

Simulating differences between forwarding short and normal-length timber

Simon Berg

J. For. Sci., 2023, 69(11):485-496 | DOI: 10.17221/41/2023-JFS  

Normal log lengths in Norway are 3–6 m (NL), but occasionally there is a demand for short timber with a 2.5 m log length (ST). There are concerns that ST could reduce the forwarders' productivity. Six type stands were created based on harvester data. Different assortment distributions, conditions, and forwarders were simulated in each type stand. It was found that an additional ST assortment almost always decreased productivity (from –15.5 to +4%). Increased forwarding distance (m), more difficult driving conditions, and increased log concentration [m³·(100 m strip road)^–1] decreased the...