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Results 181 to 210 of 740:

Investigation on Zagros forests cover changes under the recent droughts using satellite imageryOriginal Paper

Marjan Goodarzi, Mehdi Pourhashemi, Zahra Azizi

J. For. Sci., 2019, 65(1):9-17 | DOI: 10.17221/61/2018-JFS

Oak decline phenomenon has recently led to considerable dieback within Zagros forests, western Iran. In the present study, Landsat imagery (2005 to 2016) and synoptic station data were used to study the forest dieback in Dorood, Lorestan province. Sixteen vegetation indices were calculated and values in each year were obtained. The correlations between the index and climatic parameters of rainfall, temperature and relative humidity were investigated. Results showed that the correlation of some indices with rainfall and the correlation of other indices with temperature were more than 70%. Optimized soil adjusted vegetation index had 80% correlation with annual rainfall and the modification of normalized difference water index was correlated with average annual temperature by 75%. Using the numerical value changes of the indices, a map of forest cover change was prepared in four classes; healthy, weak, moderate and severe dieback and the process of its change were compared with the trend of variations in regard with rainfall values in the study period. There was a close relationship between changes in the area of forest cover dieback and rainfall and temperature values.

Growth response of seven multipurpose tree species to climatic factors: A case study from northwestern Himalayas, IndiaOriginal Paper

Sucharita Panda, D.R. Bhardwaj, C.L. Thakur, Prashant Sharma, Dhirender Kumar

J. For. Sci., 2022, 68(3):83-95 | DOI: 10.17221/159/2021-JFS

Identification of the species for dendrochronological studies is of great relevance to understand various aspects of climate change. However, in the northwestern Himalayan region, dendroclimatological investigations are confined to conifer species, with broadleaved species being disregarded. Thus, the present study was conducted to assess the growth response of seven multipurpose tree species (MPTs), namely Bauhinia variegata, Celtis australis, Grewia optiva, Paulownia fortunei, Toona ciliata, Ulmus villosa and Melia composita to local climate variables, viz. temperature as well as rainfall (seasonal, monthly, average) and CO2 level by evaluating the climatic signal in tree ring chronologies at Solan district, India (altitude 1 250 m) in the mid-hills of the northwestern Himalayas. The results indicated that only the maximum, rainy season temperature and CO2 level varied significantly (P < 0.05) between 1991 and 2017. Only G. optiva exhibited a significant (P < 0.05) tendency toward increased growth. C. australis has a remarkable negative correlation with temperature variables, viz. average, maximum, spring season, March temperature, whereas T. ciliata exhibits a positive correlation with temperature variables, such as rainy season, average and April temperature. Similarly, winter, total and December rainfall have a profound effect on P. fortunei, while March rainfall adversely affected the growth of B. variegata. On the other hand, G. optiva demonstrated sensitivity to both temperature (February and May) and rainfall variables (winter, February and May). U. villosa recorded a positive correlation with rainfall (autumn and October rainfall) but a negative correlation with temperature variables (maximum and April temperature). Elevated CO2 levels affected only two species (G. optiva, M. composita) out of the seven selected species. Our findings will contribute to a better understanding of the climate growth relationships of investigated tree species, as a result, to more accurate projections of the effects of climate change on these MPTs and directing future studies.

Geographical forest zonation: Perspectives, history and useReview

Petr Dujka, Antonín Kusbach

J. For. Sci., 2024, 70(7):335-352 | DOI: 10.17221/5/2024-JFS

The rate of climate change advancement and its predicted impact are valid reasons for intense discourse on the topic of choosing the most suitable silvicultural and adaptation measures for the longevity and sustainability of forest communities. Changes in growth conditions of plants can be expected in both vertical (altitudinal) and horizontal (geographical) directions. The anticipated occurrence rate of these changes should, according to climate models, be higher than the natural adaptability rate of longevous tree species. This study focuses on the possibility of utilising regional geographical units of the Czech Republic (Central Europe) – Natural Forest Areas (NFAs) – for introducing the principles of assisted forest migration to national silviculture policies in order to find solutions for the predicted climate change scenarios. The primary objectives are (i) to review the history of the NFA concept, (ii) to discuss the perspectives of NFAs with regard to climate change, and (iii) to propose possible solutions for further development in comparison with alternative approaches to horizontal classification of the Czech Republic. This study is the first of its kind that provides a complete textual and graphic overview of the NFAs' history from 1959 to 2018, highlighting the purpose of NFAs as both frameworks for the maintenance of the genetic potential of forest tree species' populations and frameworks for long-term strategic management planning. Further development of the concept is discussed in connection with the main principles of assisted forest migration and the possibility of employing geospatial modellation analyses for a more precise definition of current NFA borders. An assessment of the areas' potential is also debated, mainly with an emphasis on the zonality of forest sites.

Soil aggregate stability index and particulate organic matter in response to differently afforested lands in the temperate regions of IranOriginal Paper

Masoomeh Soleimany, Jamshid Eslamdoust, Moslem Akbarinia, Yahya Kooch

J. For. Sci., 2021, 67(8):376-384 | DOI: 10.17221/20/2021-JFS

Aggregate Stability Index (ASI) and particulate organic matter (POM) are strongly influenced by land use and management. This work illustrates the effects of plantations on ASI and POM-C and POM-N in northern Iran. Three plantations of P. deltoides (PD), T. distichum (TD), A. subcordata (AS), and a fourth site ‒ adjacent abandoned lands (BL, as control) were selected. Soil samples were taken within 16 quadrats of each plantation and BL from the two depths of 0-15 cm and 15-30 cm during the summer. Soil C was significantly higher under TD (2.10%) than under BL (2.02%) > PD (1.61%) > AS (1.30%). Soil N was found in ranked order of AS (8.99%) > TD (7.82%) > PD (5.30%) > BL (3.68%) (P < 0.019). The significantly higher ASI was found under TD (57.49) in comparison with PD (53.10), BL (51.23), and AS (36.57). The POM-C was as follows: TD (0.209%) > PD (0.141%) > AS (0.139%) > BL (0.075%) (P = 0.020). The highest POM-N was found under TD (0.035), followed by AS (0.0284%), PD (0.0288%), and BL (0.007%). The results indicate the positive effect of afforestation on soil ASI and POM-C and POM-N, especially in the surface layers of soil.

Burned area determination using Sentinel-2 satellite images and the impact of fire on the availability of soil nutrients in SyriaOriginal Paper

Rukea Al-hasn, Raed Almuhammad

J. For. Sci., 2022, 68(3):96-106 | DOI: 10.17221/122/2021-JFS

The objective of this research is the identification of burned forest areas that occurred in Syria from September 2nd to October 15th, 2020. Forest fire risk classes were determined using Sentinel-2 images. Normalized Burn Ratio (NBR), Differenced Normalized Burn Ratio (dNBR), and Burned Area Index for Sentinel-2 (BAIS2), and Normalized Difference Vegetation Index (NDVI) were used for the identification how much the forests have been destroyed and to establish fire risk classes. According to the study results, the size of the vegetation area that was destroyed due to fire was determined, and the probability of the forest fire exposure of these areas was established. The fires also altered some chemical properties in the soil during the combustion process. Thus, this study was focused on the impact of fire on the availability of soil nutrients. Soil samples were collected from three depths (0-10 cm, 10-20 cm and 20-30 cm) under the forest land a month after the fire in three locations: Al-Fazeen, Sawda and Gard Al-rihan. Pine (Pinus brutia) trees cover these areas. The results of this study indicated that the fire increased pH, EC and sand, the fire also led to an increase in the solubility of the available major soil elements N, P and K. There was an increase in the solubility of the soil microelements Zn, Cu, Mn and Fe while the content of organic material and silt and clay ratio decreased at the three sites in comparison with unburned soil.

Methods for monetary valuation of ecosystem services: A scoping reviewReview

Egor Selivanov, Petra Hlaváèková

J. For. Sci., 2021, 67(11):499-511 | DOI: 10.17221/96/2021-JFS

Adequate assessment of ecosystem services is important for the development of policies and management plans related to forestry activities and the environment. Carefully identified ecosystem values can determine which options policy makers should prioritize to provide the greatest benefit. There are numerous methods used by researchers to evaluate ecosystem services. The most widely applied methods are monetary valuation methods, they are often deemed to be the most pragmatic language when it comes to communication with political and business institutions. The main goal of this review is to analyse available literature using the methodology particular to the scoping review approach in order to identify and describe valuation methods that can be applied for monetary assessment of ecosystem services. As a result of the scoping review, over 20 monetary valuation techniques (including several less common methods such as willingness to sell and Delphi method) were derived from 16 literature sources. In the process of compiling the range of different methods, a few flaws and gaps in the communication of methods were observed such as lack of consistency in the names of different methods and mixing up concepts. In addition, a few areas for future research are suggested.

Preliminary assessment of effect of disturbance on natural regeneration in gaps of different sizesReview

Maame Esi Hammond, Radek Pokorný

J. For. Sci., 2020, 66(5):185-196 | DOI: 10.17221/25/2020-JFS

The study focused on natural regeneration of European beech (Fagus sylvatica), Norway spruce (Picea abies) and European larch (Larix decidua) within very small and four times bigger size gaps following a disturbance at a mixed temperate forest in the Czech Republic. In spring 2013, experimental gap design starts, when 1 m2 circular sampling plots along transects were delineated within four selected naturally occurring canopy openings with size below 20 m2. In December 2013, these initial canopy openings were artificially enlarged by felling to 226 m2 for small and 904 m2 for big gaps. Regeneration was monitored in the next two consecutive growing seasons after disturbance. Light conditions were measured before and after disturbance. Results indicated that four times larger gaps increased twice levels of light conditions, and that diffuse light starts to equilibrate to direct light there. Large gaps were favouring larch regeneration. Beech regeneration was predominant, independently on gap size as the study area belongs naturally to Beech Forest Vegetation Zone, however, the decline of spruce regeneration was presumably linked to drought. Gap size explained variation of larch regeneration in gaps. Contrarily, gap size could not be associated with the prolific regeneration of beech and abysmal regeneration performances of spruce in gaps.

Effect of different pre-treatments on seed germination of Prosopis juliflora and Dalbergia sissoo: a step towards mutation breedingOriginal Paper

Muhammad Javed Asif, Atif Ali, Muhammad Zaid Mazhar, Ayyoub Tanvir, Bilal Zia, Iqra Anmbreen, Muhammad Zohaib Anjum, Muhammad Shabir Mahr

J. For. Sci., 2020, 66(2):80-87 | DOI: 10.17221/64/2019-JFS

For improving the seed germination of Prosopis juliflora and Dalbergia sissoo different treatments were tested, including side cutting, abrasion, overnight soaking in boiling water, scalding in actively boiling water for 1 minute and immersion in 30%, 60% and 95% H2SO4 solution. Results showed that abrasion with sandpaper and side cutting were the most effective methods to break seed dormancy in both species, while scalding in actively boiling water for 1 minute, overnight soaking and different concentrations of H2SO4 gave low to zero seed germination. Based on the positive effects of scarification it was concluded that seed dormancy in both species was due to water impermeability of the seed coat. Mutation breeding involves the treatment of large quantities of seeds, therefore abrasion with sandpaper was the most efficient and less labour-intensive method; this method was subsequently used for determination of LD50 as it is a prerequisite in a mutation breeding program. Abrasion before irradiation had a positive effect on P. juliflora whereas it had a negative effect on D. sissoo seeds. Seeds of both species were exposed to different doses of gamma rays such as 0, 100, 200, 300, 400 and 500 Gy using a 60Co source. The LD50 for P. juliflora was 651 Gy based on the rate of seed germination indicating that P. juliflora had tolerance to irradiation and low radiosensitivity to gamma ray. A high LD50 of 1097 Gy was observed for D. sissoo, suggesting high tolerance to irradiation and very low radio sensitivity. These findings will help to initiate a mutation breeding program in both species to obtain desirable mutants with desirable characteristics such as thornless genotypes, better tree form, disease resistance and increased genetic diversity.

Potential of mixed Picea abies (L.) Karst. and Pinus sylvestris L. forests in lowland areas of Central BohemiaOriginal Paper

Pavel Brabec, Jakub Brichta, Zdenìk Vacek, Stanislav Vacek, Václav ©imùnek, Vojtìch Hájek

J. For. Sci., 2023, 69(11):470-484 | DOI: 10.17221/76/2023-JFS

Mixed forests play a key role in terms of stability, production potential, and adaptation to climate change. In addition, the studied Norway spruce [Picea abies (L.) Karst.] and Scots pine (Pinus sylvestris L.) belong to the most economically important tree species in Europe. The objectives were to determine the effect of the species composition of these two tree genera on the production, structure, diversity, and growth of mixed stands at lower elevations in the Czech Republic. Based on dendroecological samples, research was also carried out on the influence of climatic factors and climate change on the radial growth of these trees of interest. Mixed forests showed higher timber production by 29.8% compared to spruce and pine monocultures. The production of mature stands ranged from 328 to 479 m3·ha–1. Spruce achieved higher radial growth, but its growth variability was higher than that of pine. Compared to precipitation, temperatures had a greater influence on the radial growth of both tree species, especially in the growing season. In terms of diversity, mixed stands achieved significantly higher structural differentiation and overall diversity compared to monospecific variants. Mixed stands can achieve higher production potential, diversity, and especially resistance to climatic extremes in the lowland regions of the Czech Republic. The differences between mixed stands and monocultures, i.e. the effect of tree species mixing, depend on the appropriate proportions of tree species and their spatial pattern.

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

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 Üllõi 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 function with R2 ranging from 0.9948 to 0.9989. Except for PL251, the A/PPFD curves of the tested clones increased steadily with increasing illumination levels but flattened at the 600 µmol·m–2·s–1 PPFD level due to the effect of photorespiration on the assimilation rate. For PL251, the A/PPFD curve decreased at the 1 200 µmol·m–2·s–1 PPFD level. Unlike A/PPFD results, the PSII/PPFD exponential curve decreased as the PPFD level increased. Europe is forecast to experience significant negative climate change factors, including increased drought, heat, and irregular precipitation. Under such conditions, relatively drought-tolerant tree species such as black locust will play a vital role in new afforestation and uninterrupted wood supply. Consequently, growing and improving newly bred black locust clones, including the ecophysiological studies of relatively drought-tolerant clones, is increasingly vital.

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

Vladimir ®ikiæ, 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.


A pilot study of continuous cover forestry in boreal forests: Do remaining trees affect forwarder productivity?Short Communication

Jussi Manner, Back Tomas Ersson

J. For. Sci., 2023, 69(7):317-323 | DOI: 10.17221/44/2023-JFS


According to the literature, forwarding productivity depends chiefly on log concentration, the number of assortments, mean log volume, load-size, slope, and extraction distance. However, there is not much scientific knowledge available on forwarding in continuous cover forestry (CCF) in boreal forests, nor whether the presence of remaining trees actually affects forwarding productivity. Thus, the objective of our study was to isolate the effect of remaining trees (i.e. stand density) on forwarding productivity during CCF, specifically selection cutting. The results showed that productivity was explained mainly by the log concentration, while other factors had at most minor effects. Most importantly, stand density did not significantly affect forwarding productivity, ceteris paribus. Thus, we conclude that remaining trees do not affect forwarding productivity in boreal forests. Although the study results from this CCF operation must only be cautiously applied to even-aged forestry, our results raise a general question: do we need separate productivity models for thinning and clearcut operations in boreal forests if remaining trees (stand density) do not affect forwarding productivity? Because of the small dataset, we consider our paper to be a pilot study whose findings need to be verified by studies based on larger datasets including several operators and stands.

Responses of soil-inhabiting mesostigmatid mites to deforestation and disturbance in oak (Quercus brontii) forests of southwestern IranOriginal Paper

Ali Bagheri-Kordeshami, Jahangir Khajehali, Farshid Nourbakhsh, Masoud M. Ardestani

J. For. Sci., 2021, 67(12):562-569 | DOI: 10.17221/54/2021-JFS

The impacts of deforestation on edaphic mesostigmatid mites were investigated in oak forests of Lordegan, southwestern Iran, from April to October. A total of twenty-one species belonging to eighteen genera and ten families were collected and identified. The Shannon-Wiener, Simpson, Jaccard's and Margalef biodiversity indices were used for data analyses. Among the collected species, Antennoseius bacatus with 29% and Sessilunchus hungaricus with 16% relative abundance were the most abundant and dominant species in human-disturbed and natural forests, respectively. The estimated values were higher in natural oak forest than in disturbed and cultivated habitat. Significant differences were observed in soil nitrogen content and soil organic carbon between the two habitats, but not in pH values. Significant effects of sampling time and habitat were found on all four indices, but the effect of their interactions on these indices was not significant. It can be concluded that the changes in soil quality that resulted from deforestation may have a major role in reducing the soil mite density and related diversity indices in disturbed forests.

Effect of LED lights on the in vitro growth of Pinus pseudostrobus Lindl., plantsOriginal Paper

Luis Alberto Marín-Martínez, Lourdes Georgina Iglesias-Andreu

J. For. Sci., 2022, 68(8):311-317 | DOI: 10.17221/43/2022-JFS

Pinus pseudostrobus Lindl. is a species endemic to Mexico and is widely used in reforestation programmes, as it is highly adapted to poor, shallow, limestone soils and has high commercial importance. However, it is necessary to preserve this genetic material since it is in trouble due to high rates of deforestation, land use change, and forest fires, so it is necessary to have effective strategies to obtain good quality seedlings. Due to the properties of LED (light emitting diode) lamps used for illumination in the production of in vitro plants, the effects of two different lighting systems (LED and fluorescent) on an in vitro culture were analysed for the morphological characteristics of the growth and photosynthetic pigment content in P. pseudostrobus seedlings. The length and root size of the seedlings were affected by the type of illumination, where a red LED light was the most effective at 30 days of evaluation. However, a blue LED light was equally effective as a red LED light at 60 days of seedling development. On the other hand, the fluorescent light was better in terms of the number of needles in the first stage, but we found the blue LED light to be better in the second stage. For the photosynthetic pigment content, the highest values were found with the blue LED light. The results showed that the LED lighting system favours the growth, development, and photosynthetic pigment content of the species under study.

Old Juniper Troll stand – The oldest shrub population from ScandinaviaOriginal Paper

Jiøí Lehejèek, Matìj Roman, Martin Lexa, Paul Eric Aspholm, Jiøí Ma¹ek

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 ± 148 years) from Scandinavia with the oldest individual being 683 years old. This is a conservative estimate, as shrubs in extreme environments do not form even a single row of cells in some years. The cross-dating issues of poorly growing shrubs do not fully allow to rely on climate sensitivity of the juniper population studied, although the species' potential for dendroclimatological reconstructions is generally considered high, also because the common juniper is an abundant woody species distributed globally. Old populations present an important gene source in plant recruitment, particularly in the context of the present environmental change.

Analysis of forestry work accidents in five Australian forest companies for the period 2004 to 2014Original Paper

M.R. Ghaffariyan

J. For. Sci., 2016, 62(12):545-552 | DOI: 10.17221/80/2016-JFS

There is little knowledge available regarding Australian forestry work safety and accident rates. Machine operators and forestry workers are vital parts of the forestry sector and their health and well-being can greatly impact on their work quality and efficiency. To increase our knowledge of forest workers' safety this project aimed to analyse the frequency, type and root causes of work accidents which occurred within different forestry activities of five industry partners of Australian Forest Operations Research Alliance over the period from 2004 to 2014. A questionnaire was designed and distributed to the partners to collect the safety incident reports. Total number of work accidents was 470 for a period of 11 years (a rate of 43 accidents per year). Considering the estimated yearly production rates of the industry partners that participated in this project, the accident severity rate was 14.40 accidents per million m3 of harvested wood. The majority of accidents occurred in harvesting operations (37%) and forest management (30.2%). Based on the results 8.1% of the accidents occurred during firefighting and 24.3% of work accidents occurred in other forestry activities. Main root causes of accidents for different types of activities were personal errors such as lack of personal protective equipment, operator error, poor body position and poor techniques applied. Work safety training could be delivered to forestry personnel to minimise accidents caused by personal errors. Back and shoulder (as upper parts of the body) received most injuries. To avoid/reduce muscular damage (such as strain and sprain) the workers should be provided with proper ergonomic training.

Impact of different factors degrading cork oak stands in the Mediterranean region: A case study from AlgeriaOriginal Paper

Salah Eddine Younsi, Yasmine Adjami, Rym Ghanem, Billel Bouchaib, Mohamed Laid Ouakid

J. For. Sci., 2021, 67(12):570-581 | DOI: 10.17221/77/2021-JFS

In recent years, the cork oak forests that characterise the Mediterranean region have been exposed to various factors that result in their degradation. These cork oak trees, due to increasingly accentuated anthropogenic activity, undergo withering at different scales.The objective of the study is to assess the impact of various factors that degrade cork oak forests in the Mediterranean region located in northeastern Algeria, and this was achieved by prospecting 22 sampling locations. This allowed the creation of a database containing 745 trees that were observed and 27 measured variables. Different readings were then taken into consideration based on measurements and sometimes on ratings. The impact of several biotic and abiotic factors, which affect and damage the health of cork oak, was identified. These factors include in particular the infestations by xylomycetophagous insects such as Platypus cylindrus and Xyleborus sp., which can potentially infest the cork oak trees that we observed one year after bark harvesting. On the other hand, the stationary descriptors such as altitude, slope, exposure, etc., are important for the dendrometric and exploitation characteristics, but their unfavourable values do not necessarily lead to tree mortality; for example, medium to low slopes, associated with average altitudes of 600 m a.s.l., may ensure the healthiest trees like in our case study. Finally, we were able to find that certain decline factors may affect a particular category of trees, either because they are older, taller or have a large girth, or because they are subject to inadequate debarking.

Effects of tree diameter and some working conditions on residual stump height following selective logging - Short CommunicationShort Communication

Farshad KEIVAN BEHJOU, Omid GHAFFARZADEH MOLLABASHI

J. For. Sci., 2018, 64(2):91-95 | DOI: 10.17221/100/2017-JFS

The forests in the north of Iran are located on steep terrains. The stump heights were measured in three compartments under selective management in Caspian forests. The objective of this study was to evaluate the effects of site characteristics on stump heights. The trees were felled with a Stihl chainsaw in the region. Each compartment included three slope categories (0-15, 15-30, and 30-60%) and three diameter categories (40-60, 60-80, 80-100 cm). Also, three snow depths were identified in the felling places (0-15, 15-30, and 30-45 cm) because of the felling season. The results of ANOVA test indicated that slope categories and snow depth had significant effects on stump heights (P < 0.01). In addition, the results proved that the stump diameter of harvested trees had no significant effect on residual stump heights (P > 0.05). Besides, there is a multiple linear relationship between stump height (dependent variable) and ground slope and snow depth as the independent variables.

Comparison of the bond strength of oak (Quercus L.) and beech (Fagus sylvatica L.) wood glued with different adhesives considering various hydrothermal exposuresOriginal Paper

P. Král, P. Klímek, D. Dìcký

J. For. Sci., 2015, 61(5):189-192 | DOI: 10.17221/95/2014-JFS

The investigation of the hydrothermal exposure effect on the glue-line strength is obvious when outdoor application of wood products is in option. In our research the bonding quality of oak (Quercus L.) and beech (Fagus sylvatica L.) wood was tested in different conditions according to EN 205. After each exposure the lap joint test specified the shear strength of wood bonded with PVAC and PU adhesive. In our research different behaviour concerning both types of adhesives and selected wood species was observed. The most significant decrease (-80%) of the shear strength was found when the PVAC was used to bond oak wood. Therefore the PVAC adhesive is most likely less suitable for the bonding of the block board in outdoor conditions. On the contrary, the best results in the same conditions were obtained by the oak when the polyurethane adhesive was used. It indicates that the PU adhesive is more suitable for the bonding of oak wood. Considering results of beech wood, there were not found this interaction.

What does the mandible say about wild boar: Ontogenetic development, sexual dimorphism and habitat preferencesOriginal Paper

Klára Ko¹inová, Richard Policht, Ondøej Matìjka, Vladimír Hanzal, Milo¹ Je¾ek, Tomá¹ Ku¹ta, Vlastimil Hart

J. For. Sci., 2022, 68(2):61-71 | DOI: 10.17221/128/2021-JFS

Wild boar (Sus scrofa L.) is one of the most discussed game species, distributed across Europe, therefore the management of this species is considered important. This management should be based on data presented, population quality and preferences and craniometric dimensions show the development of the individual and its prosperity. A sample of 148 male and 153 female wild boar mandibles was studied to compare differences in craniometric measurements, especially to find out wild boar environmental demands and population trends. The width of the caput mandibulae and angle of the mandible showed significant difference between males and females. Measurements analysed with forest area size and other data also showed that larger craniometric dimensions were reached in hunting areas with at least 200 ha of forested area, which may be due to the wild boar's need for safety and vegetative cover in the first months of piglet development with respect to its home range. The development of young wild boar is dependent on rest and shelter in the first months of life. A forest cover of at least 200 ha appears to be sufficient in this respect. Information on habitat preferences and individual development can lead to improvements in wild boar management.

The distribution of Castanea sativa and its ability to regenerate in the Czech RepublicShort Communication

Jaroslav Holu¹a, Kamil Holý

J. For. Sci., 2024, 70(12):634-637 | DOI: 10.17221/71/2024-JFS

Castanea sativa is a type of cultivated chestnut tree found in the Czech Republic, growing in both lowland and midland regions. These trees are usually planted individually or in pairs, with over half of the plantings located in urban areas. One-fifth of chestnut trees thrive in parks, while chestnut orchards or forest stands make up only one-tenth of the areas where chestnut trees are located. In the Czech Republic, approximately 30 ha are covered by chestnut trees. Regeneration of chestnut trees occurs in only 6% of the localities due to regular lawn mowing. However, 40% of the surveyed forests showed signs of regeneration, demonstrating the species' ability to regenerate under Central European climate conditions.

Effect of forest management on the genetic diversity of Abies hidalgensis, a threatened species with restricted distributionOriginal Paper

Elena Rosales-Islas, Pablo Octavio-Aguilar

J. For. Sci., 2023, 69(5):193-204 | DOI: 10.17221/13/2023-JFS


Abies hidalgensis is an endemic species from the state of Hidalgo, Mexico, that has been registered only in nine fragmented relict populations that have a total of 1 000 individuals among them. Intensive forest management takes place in five of the populations under specific programs focused on Pinus spp. Still, it is necessary to know the impact of these activities on the genetic diversity of the threatened species, if restoration and conservation strategies are to be proposed. The aim of this work was to estimate the effect of forest management on the genetic structure of A. hidalgensis using seven nuclear molecular markers developed for A. guatemalensis (Ab07, Ab08, Ab09, Ab12, Ab15, Ab20, Ab23). The species was sampled growing under two different conditions; (i) areas under forest management and (ii) conserved areas. Two indexes of genetic diversity were evaluated, observed and expected heterozygosity. The genetic structure was determined by an analysis of molecular variance and a Bayesian assignment model. A bottleneck analysis was also carried out. The populations were found to have a common genetic base (differen­tiation coefficient FST = 0.056, number of mi­grants per generation Nm = 43), which suggests recent fragmentation of the distribution, which in turn increases the bottleneck effect in managed areas (Wilcoxon probability Wp = 0.007 and 0.016). This explains the apparently high heterozygous level (He = 0.69) and low inbreeding. Our results are important as they may be used to design strategies for management and conservation of A. hidalgensis.

Comparison of Scots pine growth dynamics in Polissya and Steppe zone of UkraineOriginal Paper

Viktoriia Lovynska, Andriy Terentiev, Petro Lakyda, Svitlana Sytnyk, Olexander Bala, Yuriy Gritsan

J. For. Sci., 2021, 67(11):533-543 | DOI: 10.17221/93/2021-JFS

The goal of the study was to compare the dynamic changes in individual biometric indices of Scots pine in different natural zones of Ukraine, Polissya and Steppe. Scots pine stands were mainly concentrated in the Polissya zone, and their area was 3.6 times larger than that of forests in the Steppe zone, and the total wood stock by 4.6 times. The regression equations for biometric indices of artificial modal stands were developed. A comparison of the average height, diameter, and wood stock for pine stands of site index Іа, I, and II growing in Polissya and Steppe was made. It was found that the average differences in the average height (from 1.9 to 2.6 m) are observed at the age of 15-20 years. For the average diameter, the difference increases with age and the growth of the site index. The difference in the average stock is constantly increasing with age. At the age of 20 years this difference is 20-30 m3, and at the age of 120 years from 100 to 120 m3 depending on the site index. The developed growth models can be used in planning and prioritizing appropriate forestry activities for pine stands growing in specific regional conditions.

Improving drainage conditions of forest roads using the GIS and forest road simulatorOriginal Paper

Mehran Nasiri, Behnaz Askari

J. For. Sci., 2020, 66(9):361-367 | DOI: 10.17221/16/2020-JFS

In this study a new method of locating culverts is presented with the composition of achieved discharge from hydrological analysis and simulated forest roads in RoadEng 3D simulator to improve drainage condition. Locating culverts was performed on a small scale (1:20 000, using GIS) and large scale (1:2 000, road geometric design simulator). The small-scale study regarding the achieved discharge from streams shows that the installation of some culverts is not necessary. The large-scale study also showed that the geometric design of forest road has a significant effect on locating culverts and its accuracy. To improve drainage conditions 6 culverts and 2 waterfronts taking into account the geometric design of forest road, hydrological conditions and appropriate intervals (155 m) have been proposed. No installation or lack of accuracy to find the best location of culverts may result in the occurrence of creep and landslide, so the cost of destruction would be several times higher than the cost of technical buildings construction.

Growth and structure of pre-mature mixed stands of Scots pine created by direct seeding in the boreal zoneOriginal Paper

Aleksey Ilintsev, Darya Soldatova, Alexander Bogdanov, Sergey Koptev, Sergey Tretyakov

J. For. Sci., 2021, 67(1):21-35 | DOI: 10.17221/70/2020-JFS

The purpose of the research is to analyse the successful creation of an artificial pine forest by seeding and develop recommendations for the guaranteed reproduction of pine stands in Northern European Russia. In recent decades, there has been a steady decline in the share of pine stands and their replacement with low-value and low-yielding tree species. We surveyed 12 permanent sample plots that were laid out in various variants of forest crops. The taxation parameters were obtained by a standard analysis of the experimental data. The evaluation parameters of the stands vary within the following limits: the average diameter of the pine trees varied from 21.9 to 30.9 cm; the total basal area of the pine varied from 19.1 to 38.8 m2∙ha-1; the average height of the pine varied from 20.1 to 26.8 m; the number of growing trees varied from 754 to 1 952 ha-1; the pines varied from 382 to 762 ha-1; the growing stocks of stands varied from 416 to 608 m3∙ha-1. The distribution of pine trees by thickness steps showed that all the studied samples were close to the normal distribution curve. The results of the correlation and multidimensional analyses showed that the creation method of the forest crops had a significant impact on the value of the taxation parameters. It was found that the best options for growing pure pine stands that can be recommended for practical production are plots with a large share of soil cultivation and the size of the seedbed.

Efficiency of adaptive cluster sampling and traditional sampling for coastal mangrove in Hainan of China

Y. Lei, J. Shi, T. Zhao

J. For. Sci., 2012, 58(9):381-390 | DOI: 10.17221/80/2011-JFS

Based on two species of Coastal Mangrove in Hainan of China, Sonneratia Apetala Buch-Ham and Sonneratia caseoli, we estimated the density of the two species to evaluate the efficiency of adaptive cluster sampling (ACS), simple random sampling (SRS) and traditional systematic sampling (SYS). Our initial experimental designs for ACS consisted of 5 unit areas, 6 initial sampling proportions, 4 initial sample sizes and 5 criterion values in 1,000 repetitions. From the aspect of factors influencing efficiency, we analysed the efficiency of ACS in various designs. We also compared the efficiencies of the three methods on the indexes of the relative error, the variance of density estimator and the relative sampling efficiencies. We found that ACS yielded smaller variance than the traditional sampling methods. ACS was a powerful sampling method when a population was spatially aggregated. We also determined the optimum unit area for the two species studied using the two estimators (HT and HH) of adaptive cluster sampling. They were 20 m2 (2 × 10 m), 15 m2 (3 × 5 m) for S. Apetala Buch-Ham and 25 m2 (5 × 5 m), 15 m2 (3 × 5 m) for S. caseolari, respectively.

Ca/Al ratio in Norway spruce fine roots on monitoring plots in the Czech RepublicOriginal Paper

V. ©rámek, V. Fadrhonsová, L. Jurkovská

J. For. Sci., 2014, 60(3):121-131 | DOI: 10.17221/85/2013-JFS

This article is focused on the evaluation of the Al/Ca ratio in fine roots of Norway spruce on the plots belonging to the ICP Forests monitoring programme in the Czech Republic. In total 122 fine root samples were collected from twenty plots from two soil layers of 0-10 and 10-20 cm and then analysed. The mean Ca/Al molar ratio in the fine roots from the 0-10 cm topsoil layer is higher than in the lower 10-20 cm soil layer, which corresponds to the distribution of fine roots - on average 80% of fine roots were found in the topsoil. 6% of the samples in the lower soil layer strongly indicate aluminium stress (Ca/Al < 0.1) and 30% of the samples may demonstrate the adverse effects of aluminium (< 0.2). On the other hand, no relationship was found between the Ca/Al ratio in the fine roots and the fine root biomass and vitality or crown condition. These results suggest that the potential aluminium toxicity is not the driving factor of the crown condition in Norway spruce and the Ca/Al ratio itself does not pose a risk to forest health in the region.

The impact of agricultural land afforestation on soil water content in Central BohemiaOriginal Paper

Jan Vopravil, Pavel Formánek, Darina Heømanovská, Tomá¹ Khel, Karel Jacko

J. For. Sci., 2021, 67(11):512-521 | DOI: 10.17221/108/2021-JFS

In the Czech Republic, the afforestation of agricultural land has been supported by providing subsidies from the government and the European Union. Afforestation of less-productive agricultural land provides many benefits including carbon sequestration, soil erosion control, biodiversity, water retention, cooling, social benefits, decreasing noise and light pollution, increasing air quality, wind speed reduction, oxygen production, wood production and non-wood products. In some aspects, it is possible to produce wood of the same quality on former agricultural land compared to permanent forest land. In this study, we attempted to find out the course of temperatures and volumetric water content as well as some other physical soil properties (at depths of 20, 40 and 60 cm) 9 years after the afforestation of agricultural land (warm, mild dry region of the Czech Republic) with a mixture of broadleaved tree species (Quercus robur L., Quercus rubra L. and Acer platanoides L.) or monospecific Pinus sylvestris L. stand; the study was performed in the period from April to the beginning of November 2020. Concerning the studied physical soil properties, the value of bulk density was higher (and total porosity lower) at a depth of 20 cm in Pinus sylvestris L. compared with agricultural land or the mixture of broadleaves; the water stability of soil aggregates was higher after the afforestation with the mixture of broadleaves. The temperature was lower in the soil of afforested plots (at all studied depths) compared to the agriculturally used land. Differences in rainfall interception, transpiration, soil(and forest floor) properties and other factors could influence the obtained values of water content in the soil of the studied plots. The average volumetric water contents were the highest in the plots with Scots pine (depth of 20 cm) and broadleaves (depth of 40 cm), and on the control plot (depth of 60 cm). The volumetric water content at a soil depth of 20 cm was not significantly (P > 0.05) different when the plot with Scots pine and agriculturally used land were compared. In all other cases and depths, the differences between plots were significant (P < 0.05).

Support for silver fir (Abies alba Mill.) in managed forestsEditorial

Jiøí Novák, Du¹an Kacálek

J. For. Sci., 2023, 69(2):41-43

City longhorn beetle (Aeolesthes sarta): A review of the species, its distribution, ecology, damage, prevention and controlReview

Umer Hayat

J. For. Sci., 2022, 68(6):199-212 | DOI: 10.17221/34/2022-JFS

The city longhorn beetle (Aeolesthes sarta) (CLB) (Coleoptera - Cerambycidae) is a polyphagous invasive pest of both healthy and suppressed broadleaved trees in central Asia. CLB causes a great degree of damage in the countries of its origin. To understand this pest in a better way, a detailed review study has been conducted to gather all the valuable information related to the CLB. This review study covers the main aspects of the CLB, its morphology, ecology, distribution, damage, and control measures. The life span of the CLB is two years. It is mainly distributed in the central Asian countries and preferably damages broadleaved tree species, especially Juglans regia, Populus alba, P. euphratica, Acer spp, Salix alba, S. babylonica, Malus pumila, M. sylvestris, Platanus orientalis and Ulmus spp. Effective control and management practices include cutting, removing + burning of infested trees, cultivating high resilient tree species, use of biocontrol agents (i.e. fungus), and use of aluminium phosphide as a pesticide to significantly help control the CLB population. A CLB invasion in a new favourable habitat could impose a serious threat to broadleaf forests and plantations. Therefore, the keen monitoring and surveying of woodland management techniques are recommended. The strict monitoring and inspection of traded wood material at airports and seaports are highly recommended. There is a need to conduct multiple research studies to profoundly understand the CLB phenology, ecology, transportation mode, and damage severity to bridge the gap.

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