Fulltext search in archive
Results 181 to 210 of 527:
Impacts of Central Tire Inflation Systems application on forest transportation - ReviewReviewMohammad Reza GHAFFARIYANJ. For. Sci., 2017, 63(4):153-160 | DOI: 10.17221/111/2016-JFS Central Tire Inflation Systems (CTIS) have been introduced to forestry transportation in the last 30 years to the point the forest industry is one of the biggest users of the technology (Pletts 2006). The benefits of operating with this CTIS technology mentioned in the literature include: (i) reduced road surfacing and/or base course requirements, (ii) reduced road maintenance, (iii) reduced driver fatigue and medical complaints, (iv) lower vehicle operation costs, (v) increased vehicle mobility, (vi) extended haul seasons (Bradley 1995). This paper presents a literature review of previous international studies on the impacts of CTIS. This document can assist the forest industry and research users to gain basic information on this transportation technology. |
The structure of Scots pine and Black locust forests in the Northern Steppe of UkraineOriginal PaperV. Lovinska, S. SytnykJ. For. Sci., 2016, 62(7):329-336 | DOI: 10.17221/120/2015-JFS The article describes the distribution of areas of Scots pine (Pinus sylvestris Linnaeus) and Black locust (Robinia pseudoacacia Linnaeus) stands within the Northern Steppe of Ukraine based on forest biometry data. The total area of Scots pine stands is 21,472.9 ha, of Black locust it is 17,683.7 ha, which corresponds to 24.6 and 26.9% of the total forest-covered area. Scots pine is partly naturally, partly artificially regenerated. Black locust stands are man-made forests only. Both species form mainly pure stands within the study area. Mean age of Scots pine is around 60 years with a mean wood stock of 292 m3.hа-1. The dominant Black locust stands are overmature ones with a mean age of 43 years and a mean stock of 149 m3.hа-1. Generally, for both species, an increase in mean wood stock was observed, reaching its maximum at 71 to 75 (Scots pine) and 81-85 (Black locust) years of age. It has been demonstrated that the largest area of Black locust stands is represented by relatively rich soil conditions (54.3%), whereas in Scots pine stands there are relatively poor soils (56.5%). |
The mycological study of conifers in Tbilisi and its surroundingsOriginal PaperIrina Danelia, Nino Zaqariashvili, Lia Amiranashvili, Gulnara Badridze, Salome KvitsianiJ. For. Sci., 2021, 67(10):464-476 | DOI: 10.17221/79/2021-JFS Extensive microbiological research was carried out in Tbilisi (capital of Georgia) and its surroundings to determine the causes of massive disease and dieback of urban coniferous plantations. The biological material was picked up in June-July 2020 from trees with various degrees of the disease in 42 different localities. 247 conifers (15 species) were examined microbiologically. 1 169 samples of microscopic fungi were isolated. Based on cultural-morphological and molecular-genetic (PCR) studies, 34 strains were identified to the species level, 17 to the genus level, and 1 strain to the family level. Ascomycota were represented by 15 families and 33 species, Basidiomycota by 1 family and 2 species and Zygomycota by 2 families and 2 species. Among the isolated strains, 9 species were clearly dominant and found in all studied coniferous species: Alternaria alternata (Fr.) Keissl, Sphaeropsis sapinea (Fr.) Dyko & B. Button, Epicoccum nigrum Link., Sordaria lappae Potebnia, Curvularia spp., Dothiorella spp, Nothophoma quercina (Sydow & P. Sydow) Q. Chen & L. Cai, Phoma odoratissimi Q. Chen, Didymella aliena (Fries) Q. Chen & L. Cai. It may be supposed that massive activation of pathogenic fungi is the result of weakening of plant immunity on the background of increasing abiotic stresses in Tbilisi over the years; which led to an imbalance between latent pathogens and host plants and eventually to the depressing consequences of trees dieback. |
Comparison of the approach to determination of the rotation period of forest stands in the Czech Republic and in the Slovak RepublicOriginal PaperMichaela Korená Hillayová, Kateřina Holušová, Klára Báliková, Ján HolécyJ. For. Sci., 2022, 68(10):413-422 | DOI: 10.17221/107/2022-JFS The exact determination of the rotation period is still a current and important essential issue of forestry. It attracts the attention of forest economists, managers and owners worldwide, not only of forest economists but also of forest managers. The rotation period is defined by physical, technical or financial parameters of forest management. Therefore, it is necessary to distinguish between the biological and the economic optimal rotation period. A fundamental challenge in forest management is the need for appropriate determination of the rotation period. The primary interest of our research was to compare the effective legislation for the determination of the rotation period in the Czech Republic and in the Slovak Republic. Scientific methods such as document analysis and questionnaire survey were applied. The results of the legislation analysis and other related documents were compared with the expert opinions of the relevant stakeholders. Those who affect the decision process related to the problem and those where are "affected" by the problem were involved in the study. Results show that respondents do not agree with the regulation of rotation period according to effective law. Moreover, they consider it as not usable as the conditions in forest ecosystems have changed recently, which is not considered in the legislation. |
Methodology of monitoring wood sources and consumption in the Czech RepublicOriginal PaperAndrea Sujová, Róbert Babuka, Václav KupčákJ. For. Sci., 2021, 67(1):1-11 | DOI: 10.17221/64/2020-JFS Currently, it is difficult to identify correct data on wood sources and their consumption in the Czech Republic. Official statistics of wood production are relatively limited to obtaining data that accurately captures the objective wood production, which would enable the observation of the direction or consumption of particular tree species or products. This uncertainty is then transferred to the wood flow for industrial and energy processing, and it is not possible to compose a detailed picture of how much wood and which sources enter into the wood processing and how large the total material flow is. The aim of this paper is to present an option for how to determine this lack of valid information that enables clear outcomes necessary for decision making by means of the recalculation of wood sources consumed in the Czech Republic, using the data of processing capacities and foreign trade. The reverse model better expressed a conversion value of roundwood into the products and allowed optimal approximation in the wood sources assessment. |
Responses of soil-inhabiting mesostigmatid mites to deforestation and disturbance in oak (Quercus brontii) forests of southwestern IranOriginal PaperAli Bagheri-Kordeshami, Jahangir Khajehali, Farshid Nourbakhsh, Masoud M. ArdestaniJ. 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. |
Factors affecting the development of Phytophthora alni ssp. alni infections in Alnus glutinosa L.P. Štochlová, K. Novotná, K. ČernýJ. For. Sci., 2012, 58(3):123-130 | DOI: 10.17221/26/2011-JFS Phytophthora alni is responsible for a devastating disease in alder and changes in the environment of riparian and alder carr ecosystems. One of the main approaches to solve this problem is to find naturally resistant genotypes using a series of artificial inoculation experiments, to preserve and use them in programmes for resistance breeding. However, the results of artificial inoculation experiments (screening for natural resistance) can be affected by several factors. The potential effect of the social status of the host, the presence of naturally occurring P. alni infections, the season and the size of the sections of branches used were studied in a series of infection experiments. It was found out that the development of lesions was significantly affected by the year season (the largest lesions were found in summer) and by the presence of naturally occurring P. alni infections in the sampled trees (the lesions were five times larger in healthy trees and trees recovered from natural P. alni infections compared to trees with active disease development). |
Prediction of flood discharge and flood flow depth using a hydraulic model and flood marks on the trees in ungauged forested watershedsOriginal PaperVahid GholamiJ. For. Sci., 2022, 68(5):190-198 | DOI: 10.17221/6/2022-JFS It is difficult to estimate flood discharges and the flood zones as well as to design hydraulic structures in rivers without using hydrometric stations. Furthermore, using different models to determine the mentioned cases will be accompanied by errors. Therefore, flood marks on the trunks of trees located in the Babolrood riverbed were used to determine the peak discharge, flood flow depth, and flood zone in northern Iran. First, a hydraulic model for the study river was provided using topographic maps with a scale of 1: 1 000, HEC-GeoRAS extension (GIS), and HEC-RAS model. Then, the flood marks of past floods in the form of silt and clay sediments (deposits on the trees in the riverbed) were evaluated and the maximum flood flow depth was determined. Finally, the peak discharge of the past flood was estimated by the trial-and-error method to achieve the flood flow depth in the different river reaches. Then, the hydraulic model using the flow depth data was calibrated in the reaches, and, in the final step, based on the flood marks of other reaches, the model was validated. According to the results, the maximum instantaneous discharge rate of the study flood was 155 m3.s-1 and the maximum flood flow depth was about 2 m. Furthermore, the results showed that the flood mark data in forest lands can be used as a tool for the calibration and validation of hydraulic models. The present methodology is an efficient method for determining the flood peak discharge, spatial variation of the flood depth, and flood zone in forest watersheds without hydrometric stations. |
Forecasting drying up of spruce forests in Transcarpathia (Ukraine) using the FORKOME modelOriginal PaperIhor Kozak, Taras ParpanJ. For. Sci., 2019, 65(6):209-217 | DOI: 10.17221/30/2019-JFS This paper presents the results of analysis of drying up of spruce stands obtained by the use of the FORKOME computer model. The verification of this model was conducted with field data from spruce-dominated mixed forests in Transcarpathia (Ukraine). The forecast of drying up, based on the latest version of the simulation of FORKOME computer model, allowed to evaluate results regarding bioclimatic effects on the displacement, growth, survival and death of spruce and other tree species. The modelling was performed on the basis of statistical Monte Carlo simulations. The forecast of the spruce stand dynamics was conducted for 100-year period along with control and warm-dry scenarios. The analysis has revealed the rapid decrease of biomass in the first decade as a result of spruce decline. Auto-correlation analysis of spruce and cross-correlation analysis of the relation between tree species were conducted as well. |
The perception of forests by the Czech Republic general publicOriginal PaperHana Krejčí, Marta Stárová, Ivan Hrbek, Miroslava Navrátilová, Markéta BeranováJ. For. Sci., 2019, 65(6):226-233 | DOI: 10.17221/138/2018-JFS Forests as a part of landscape do not fulfil their economic function (timber production) only but a lot of other non-economic functions, especially ecological ones. Both economic and non-economic functions are indisputable and equally important for society. The aim of this paper is to identify current attitudes to forest perceptions by citizens in the Czech Republic. Primary data were obtained by means of a questionnaire research survey which was carried out in 2018. Altogether 824 respondents took part in this survey (n = 824). From the results follows that approximately 70% of respondents visit forest at least three times a month. In connection with this, the relationship between respondents' forest visit frequency and the forest density in the region where they come from was confirmed. 60% of respondents consider the forest exploitation and forest management to be the most important cause of damage and threats to forest. In relation to forest, 46% of respondents consider forest conservation and protection to be the most important topics. |
Prediction by financial and economic analysis in the conditions of forest enterprisesReviewAndrea Majdáková, Blanka Giertliová, Iveta HajdúchováJ. For. Sci., 2020, 66(1):1-8 | DOI: 10.17221/84/2019-JFS Individual companies need to know their financial condition. They have a wide range of methods and procedures to create a system of the financial and economic analysis of a company. The analysis is focused on the evaluation of a specific group of methods for predicting the financial health of a business entity. Evaluations of the financial situation of a company are divided into point methods, mathematical and statistical methods and neural networks. The individual methods differ from each other in difficulty, in the extent of the analyzed areas and possibilities of application. The aim of this work is to assess the possibilities of using selected methods of comprehensive evaluation of companies as a tool for an analysis of the position of each company in the branch. The suitability and feasibility of each method are tested on a selected group of companies. Quick Test, Tamari Model, Beaver Model are included in this work. Based on the results, improvements and recommendations for the practical use were suggested. The results showed that the best predictive methods are Quick Test and Tamari Model, because they are quick and unequivocal when assessing the analyzed companies. An inappropriate prediction method is the Beaver model, which uses only two financial indicators to evaluate companies. |
How different approaches to logging residues handling affected retention of nutrients at poor-soil Scots pine site after clear-cutting? A case studyOriginal PaperOndřej Špulák, Dušan KacálekJ. For. Sci., 2020, 66(11):461-470 | DOI: 10.17221/143/2020-JFS Biomass nutrient loss and retention were studied at nutrient-poor forest site dominated by Scots pine where two methods of logging residues handling after clear-cutting were compared. The experiment was conducted on nutrient-poor pine-oak forest site on deep sandy-gravel unconsolidated sediments at the altitude of 255 m. There were three treatments established such as (i) control - no harvesting, (ii) whole-tree harvesting with ca. 10% of the slash retained unintentionally on site as processing residues and (iii) stem-only harvesting when small-diameter wood and slash were left on site. The third treatment was found to retain much larger amounts of nutrients in logging residues representing 16% of total above-ground dry mass which accounted for 58% of N, 32% of P, 56% of K, 22% of Ca and 28% of Mg left on site. |
Spontaneous development of early successional vegetation improves Norway spruce forest soil after clear-cutting and renewal failure: a case study at a sandy-soil siteOriginal PaperOndřej Špulák, Dušan KacálekJ. For. Sci., 2020, 66(1):36-47 | DOI: 10.17221/150/2019-JFS Clear-cutting is the most common silvicultural system. Sometimes, if the new crop is not established successfully, clearcut is left unreforested. This study focused on a site where early successional species such as silver birch (Bi) and rowan (Ro) were accompanied with Norway spruce (Sp) in 13-year-old stand from natural regeneration at 550 m of altitude at an acidic site with eastern aspect and 25% slope. We found five types of stand composition: treeless gaps, Ro-Bi, Ro-Bi-Sp, Bi-Sp and monospecific Sp. Besides these juvenile ones, adjacent 100-year-old spruce (Sp old) stand representing pre-harvesting conditions was studied. In addition to the performance of trees, organic layer (Hum), topsoil (Ah) and upper subsoil (B) horizons were sampled to study an expected shift of chemical properties after clear-cutting and secondary succession at the site of interest. Birch dominated the natural regeneration; rowan and spruce were present mostly in understorey. Old spruce was more acidic and nutrient-poorer compared to the juvenile treatments. The treeless treatment showed also slightly higher pH and comparable nutrients compared to the young mixtures. Young spruce was higher in nitrogen compared to Ro-Bi-Sp mixture. |
The crown condition of Norway spruce and occurrence of symptoms caused by Armillaria spp. in mixed standsOriginal PaperPetr Čermák, Tomáš ŽidJ. For. Sci., 2020, 66(12):483-491 | DOI: 10.17221/86/2020-JFS Mixed stands are currently supported as effective management options to reduce forest vulnerability to climate change. However, our issues about benefits of mixtures, mechanisms of their incidence and conditions for their effectiveness have yet been only partly clarified. We assessed the crown condition of Norway spruce (Picea abies /L./ Karst) and occurrence of symptoms caused by Armillaria spp. on spruce in a small area in the Drahanská vrchovina Highlands (Czech Republic) in differently mixed stands in 2002 and 2019. We found that although the broadleaf abundance affected the total defoliation of Norway spruce, the effect was unstable in time. The observed effect of altitudinal zones and Norway spruce abundance on the occurrence of symptoms of Armillaria root rot in spruce was also unstable. The drought during recent four years and the implemented forestry measures (salvage and intermediate felling) can be reasons for the relationship instability. We did not identify any statistically significant relationship between tree species diversity (Simpson's Index) and defoliation. |
Does prolonged stratification of Douglas fir influence the yield of seedlings?Original PaperK. Houšková, A. MartiníkJ. For. Sci., 2015, 61(6):268-273 | DOI: 10.17221/7/2015-JFS The paper analyses the influence of an extended period of cold stratification on the germination capacity, emergence rate and yield of seedlings in the Douglas fir as well as on the morphological parameters of one-year-old seedlings. A total of ten seed lots were used for evaluating germination capacity, originating from the Czech Republic, Slovakia, France and the USA. Germination capacity, emergence rate and yield of seedlings were analysed for two seed lots of Czech provenance on seed beds in the settings of a forest tree nursery. Tested variants involved (a) no pre-sowing treatment, (b) seed stratified for 21 days, and (c) seed stratified for 49 days. The germination capacity of the stratified seed was higher than that of the control variant for all of the seed lots. The effect of the stratification period length was zero for both germination capacity and emergence rate. Differences were identified between the stratification variants as regards germination energy and emergence rate. For the control variant, seedling yield reached only 1% and 2%. For the stratified seed, yield of seedlings of two selected Czech provenances was 18% and 16% (variant 21) and 26% and 36% (variant 49). Differences in the morphological parameters of seedlings were not straightforward. |
Effect of Oriental beech root reinforcement on slope stability (Hyrcanian Forest, Iran)Original PaperE. AbdiJ. For. Sci., 2014, 60(4):166-173 | DOI: 10.17221/93/2013-JFS Vegetation significantly affects hillslope mechanical properties related to shallow landslides and slope stability. The objective of this study was to investigate and quantify the effect of Oriental beech root reinforcement on slope stability. A part of Hyrcanian forest in northern Iran was selected for the study area. To do the research, the Wu model (WM) was used and data related to the distribution and tensile strength of Oriental beech roots were collected. Root distribution was assessed using the concept of the root area ratio and trenching method. Laboratory tensile tests were conducted on fresh roots for strength characteristics. The factor of safety was calculated for two different soil thicknesses (1 and 2 m) and slope gradients between 10 and 45°. The results showed that the root distribution generally decreased with increasing soil depth and the mean root strength value was 38.23 ± 1.19 MPa for 0.35-5.60 mm diameter range. The results verified a power relationship between tensile strength and root diameter. The reinforcement effect (Cr) decreased with depth and the strongest reinforcement effect was in the second soil layer (10-20 cm) which showed a shear strength increase of 1.47 kPa. The increased factor of safety due to the presence of roots in one- and two-metre soil thicknesses was 27-44% and 15-26%, respectively. The improvement effect of roots was increased with increasing slope gradient and shallower soil thicknesses. |
Soil properties and carbon sequestration in Persian oak (Quercus brantii var. persica) forests, IranOriginal PaperAli Mahdavi, Azadeh Maleki, Masoud BazgirJ. For. Sci., 2019, 65(7):247-255 | DOI: 10.17221/140/2018-JFS One of the important issues both in the political discussion about climate change and in forest ecosystem research is carbon sequestration. In this paper, we estimated soil carbon sequestration (SCS) in two Persian oak forest stands of different origin (seed and coppice). Soil samples were taken at two soil depths (0-15 and 15-30 cm) and locations (under the tree crown and open area) in each oak stand. Results showed that surface layers (0-15 cm) had the highest soil carbon sequestration ranging from 41.2 t.ha-1 to 47.9 t.ha-1 for both oak forests. The total SCS was higher (between 79.5 and 89.07 t.ha-1) in open areas of the two forest stands than under the crowns of oak trees. Finally, the amount of total SCS in seed originated forest (SOF) (86.52 t.ha-1) was significantly greater (P < 0.05) than in coppice forest (CF) (77.70 t.ha-1). The results indicate that a relatively large proportion of C loss in CF is due to overgrazing, forest degradation and conversion to coppice forests in the study area. |
Assessing the relationship of slope and runoff volume on skid trails (Case study: Nav 3 district)M. Akbarimehr, R. NaghdiJ. For. Sci., 2012, 58(8):357-362 | DOI: 10.17221/26/2012-JFS The effect of slope on runoff volume was evaluated on skid trails in the natural forest in the north of Iran. The objective of this study was to determine the relationship between runoff volume and slope in order to control runoff and skid trail maintenance by using water diversions. Two levels of slope > 20% and < 20% were studied in adjacent parcels in district 3 of Nav in Asalem. Treatment plots with three replications were established on skid trails after skidding and the runoff volume was recorded after duration of 3 rainfalls. The results showed that there was a positive and significant correlation between slope steepness and runoff volume, and between runoff volume and slope length (P < 0.05). Also, regression analysis results showed that there was a linear relation between runoff volume, slope length and slope steepness. Effective recommendations to control and decrease runoff volume are precise scheduling of skid trail designing, construction, maintenance and limiting skid trails to a longitudinal slope of less than 20% and rehabilitation of skid trails by using water diversions. |
The effect of forest management on the frequency of dangerous trees in the Northern forests of IranOriginal PaperMehrdad Nikooy, Alireza Ghomi, Farzam TavankarJ. For. Sci., 2019, 65(8):301-308 | DOI: 10.17221/51/2019-JFS A study of work accidents in forests has shown that dangerous trees play an important role in forest accidents. Despite the importance of safe working environments for forestry operations, the definition of these areas in natural forests is still unclear. Dangerous trees are considered those snagged with broken branches and a canopy or ones with dead trunks and stumps that have a hazard potential to the forest workers. This study investigates the frequency of these trees in the managed and unmanaged forests in the Caspian forests of Iran. In order to do the study, 15 circular plots with a total area of 1,000 square metres in two studied parcels were selected and the trees, according to their dangerous characteristics, were evaluated. The final results indicated that 66 and 50 trees per hectare had signs of being dangerous trees in the managed and unmanaged stand, respectively. A comparison of the average number of dangerous trees in the two studied parcels using the Mann-Whitney test indicated a significant difference so that the average number of dangerous trees in the managed parcel was more than the ummanaged parcel. Trees with broken branches had the highest frequency in the managed stand, while trees with a dead trunk or stump, a broken branch and canopy in the unmanaged forest were more than the other classes. Considering the relative frequency of the dangerous trees in the two study areas, identifying them could be one of the main attempts in logging safety. The existence of hazardous trees with different risk classes in each of the forest stands requires the development of specific safety instructions to deal with the risks of each tree. |
Changes in decision making and cooperation among forest owners: the Lithuanian caseOriginal PaperPivoriunas Aidas, Girdziušas SigitasJ. For. Sci., 2019, 65(11):450-459 | DOI: 10.17221/106/2019-JFS Understanding of the basic determinants of cooperation among private forest owners is of crucial importance to forest owners, private forest owners' cooperatives and other key players in the forest sector. This topic concerns complementary empirical and theoretical studies from the fields of economics and social studies. A recent study shows that private forest owners differ in their attitudes towards forest management and processes of cooperation in terms of the time perspective and, correspondingly, make different decisions in various situations related to forest management. Based on the data from two surveys, this paper shows how private forest owners' views of forest management in Lithuania have developed over the last thirteen years and finds some basic socio-economic aspects that drive cooperation among private forest owners for joint forest management. |
Orthoptera assemblages of beech stand plots during early succession stages after clearcutting -Original PaperA. Sliacka, A. Krištín, L. NaďoJ. For. Sci., 2013, 59(3):93-100 | DOI: 10.17221/48/2012-JFS Open habitats in closed forests are formed by various biotic and abiotic factors. These new habitats differ from their former parent stands in light conditions and vegetation structure facilitating their colonisation by heliophilous insects. We studied interseasonal differences (2010 and 2011) in the Orthoptera assemblages on eight clearcuts in beech forests. Using a sweeping method, altogether 20 species were recorded on the clearcuts in the first year, 26 in the second. In the second year, species number and abundance were higher in all orthopterans and also in the suborder of grasshoppers (Caelifera). In the crickets (Ensifera), interseasonal differences in the species number and abundance were not significant. The species composition differed among the plots also within individual years. In the second year, the frequency increased in 22 species (84.6%) while it decreased in four. We suggest that the ground-dwelling Caelifera species are better bioindicators of the deforested plot colonisation than the arbusticolous Ensifera. |
Considering the relationship of slope and soil loss on skid trails in the north of Iran (a case study)Original PaperM. Akbarimehr, H. JalilvandJ. For. Sci., 2013, 59(9):339-344 | DOI: 10.17221/34/2013-JFS With increasing mechanization of forest harvesting operations the impacts on soil have increased quite dramatically. The objective of this paper was to examine the relationship of slope and soil loss. This research was carried out in parcels 14 and 26 of the third district of Nav-Asalem forest in the north of Iran. Erosion plots were 75, 150 and 225 m2 with two slope classes. After each rainfall event the amount of runoff was measured; then, a sample was taken to determine the weight of soil loss. The results of correlation analysis by Pearson's test between soil loss and slope classes, soil loss and slope length showed that there was a significant (P < 0.05) and positive correlation between the mentioned factors. Also, linear regression between soil loss, slope length and slope gradient was significant. It could be concluded that studying and underlying factors that increase soil loss such as soil type, rainfall intensity, should also be taken into consideration in future. Skid trail construction and skidding should be limited to the slope of < 20%; machine traffic should be restricted. The above-mentioned conclusions can be applied to proper harvesting and management of forest ecosystems. |
LIST OF REVIEWERS - 2017List of reviewerseditorsJ. For. Sci., 2018, 64(1):I-II | DOI: 10.17221/10758-JFS |
Objective and subjective assessment of selected factors of the work environment of forest harvesters and forwardersOriginal PaperM. Jankovský, V. Messingerová, M. Ferenčík, M. AllmanJ. For. Sci., 2016, 62(1):8-16 | DOI: 10.17221/120/2014-JFS This article was aimed at assessment of selected factors of the work environment, which influenced the operators of harvesters and forwarders. The selection of the work environment factors was based on a thorough literature survey. From the survey exposure to whole-body vibrations, noise (equivalent and peak), microclimatic conditions and mental load were selected for detailed observations. The measurements were conducted according to international standards and assessed according to European or national legislation. Subjective assessment of the effects of the work environment was conducted through a structured interview. The exposure to whole-body vibrations was 0.5 m.s-2. The equivalent noise exposure was 78 dB, peak noise exposure was 130 dB. The average temperature inside the machine cabs was 17.9°C and average airflow velocity was 0.06 m.s-2. Mental load was high according to the Meister questionnaire, three operators considered the load inadequate, two considered it adequate. Subjective assessment showed that operators considered other factors to be light or no load |
Forest fires and their causes in the Czech Republic (1992-2004)Original PaperE. Kula, Z. JankovskáJ. For. Sci., 2013, 59(2):41-53 | DOI: 10.17221/36/2012-JFS Forest fires under conditions of the Czech Republic are evaluated from the aspect of their frequency of occurrence in 1992-2004 at a level of particular years, seasons, days and daytime, and causes of their origin. They are confronted with a situation in the CR in 1974-1983. Effects of climatic conditions are a limiting factor not only for the frequency of their origin but also for the size of the burnt area. Spring (April) and summer (August) culminations were balanced. The burnt area of the best part of forest fires (88.9%) was < 1 ha. The increased frequency of forest fires was noted in afternoon hours and during weekends. Areas threatened by fires are characterized by the increased visit number. In the spectrum of causes, a dominant position is taken up by fire raising, smoking and management in the forest. Railway operation and lightning represent minority causes of the origin of forest fires. In the course of the year, the structure of forest fire origin changes depending on activities in the forest and visit number. |
Determining the recreational value of forest park by travel cost method and defining its effective factorsOriginal PaperM. Pirikiya, H. Amirnejad, J. Oladi, K. Ataie SoloutJ. For. Sci., 2016, 62(9):399-406 | DOI: 10.17221/12/2016-JFS Considering the importance of recreation and excursions in household's basket of expenditures on the one hand, and not paying attention to the economic value of recreational function for natural resources and environment as non-market goods on the other hand, this paper was written with the aim of estimating the recreational value of Shahid Zare Sari Forest Park when using the individual travel cost method. Requested data sets were obtained by completing questionnaires from 302 individuals who visited the above-mentioned park in 2012-2013. In the individual travel cost method, for the investigation of distributional effects of variables on the number of travels, a linear regression model was applied. For this purpose the travel generation function using linear, double log, linear-log and log-linear forms was estimated. Among these forms, according to the econometrical parameter, a linear function was selected and parameters were estimated based on the method of ordinary least squares. The consumer surplus was 12.53 USD per each visit and the annual recreational value of 72,500 people who visited the park annually was 52,558 USD.ha-1. The findings also showed that the involved variables, travel costs, income and visitor's distance were statistically significant at 1% level and family and education were significant at 5% level. Results revealed that forest parks have a considerable recreational value that, from this point of view, can help programmers and executives, social and economic managers in the preservation planning and sustainable utilization of natural resources. |
Impact of climatic conditions on the reproductive phenological phases of European hazel (Corylus avellana L.) in SlovakiaOriginal PaperJ. ŠkvareninováJ. For. Sci., 2016, 62(2):47-52 | DOI: 10.17221/55/2015-JFS The work presents the results of phenological observations of flowering and fruit ripeness of the European hazel (Corylus avellana L.) in Slovakia in two time periods: 1964-1983, and 1994-2013. The phenological stations at elevations from 100 to 875 m a.s.l. were grouped to 7 elevation zones, each 100 m wide. In the first studied period, flowering started on 19 March on average, while in the second period it started 5 days earlier. The average duration of flowering equal to 7-9 days did not depend on the elevation, but on the air temperature and weather patterns in the different elevation zones. During the first period, the average elevation gradient of flowering was 5.6 days per 100 elevation meters, while in the second period it was reduced to 3.5 days in the entire elevation profile. In the elevation zones between 300 and 500 m, a high correlation (P < 0.01) between the onset of flowering and elevation was reduced to a moderate level of correlation due to changing environmental conditions. In 1994-2013, the ripeness of hazel nuts started on average on 30 August in Slovakia, showed low variability and moderate correlation with elevation. The phenological elevation gradient was 2.9 days per 100 m of elevation. |
Prevalence of burnout among forest workers in Mazandaran, IranOriginal PaperMajid LOTFALIAN, Fatemeh SHEIKHMOONESI, Mahbobeh SABZI, Mahbobeh ABASPOUR, Saba PEYROVJ. For. Sci., 2017, 63(2):70-74 | DOI: 10.17221/111/2015-JFS Burnout imposes consequences and costs on the organization and employees, such as frequent job and workplace replacement, frequent absenteeism and permissions, and reduced work quantity and quality. So it seems necessary to perform institutional interventions to reduce the staff burnout. The aim of the present study was to determine prevalence of burnout among forest workers in Mazandaran. This descriptive cross-sectional study was conducted on a sample of workers in the forests of Mazandaran province. Result showed that a significant proportion of workers had burnout in terms of the three dimensions of Maslach Burnout Inventory. 46.90% of respondents suffered from high emotional exhaustion, 43.36% had high depersonalization and 49.56% of respondents suffered from low personal accomplishment. In this study it was shown that people with bachelor or higher degree (compared to people with a lower education level) were in better conditions in terms of all three dimensions of burnout; they had higher personal accomplishment and higher emotional exhaustion and lower depersonalization. It was shown that burnout is highly prevalent among chainsaw operators and skidder drivers. |
Climate change impacts on the Alpine ecosystem: an overview with focus on the soilReviewS. Chersich, K. Rejšek, V. Vranová, M. Bordoni, C. MeisinaJ. For. Sci., 2015, 61(11):496-514 | DOI: 10.17221/47/2015-JFS The Alpine ecosystem is very sensitive to climatic changes, which have an influence on glaciers, snow, vegetation and soils. The aim of this review is to illustrate the effects of global change on the Alpine soil ecosystem, which is an optimal marker to record them. The manuscript enhances our understanding of the global change effect on the Alpine environment: on morphology, on ice, on vegetation and points out how the cycles of soil nutrients equilibrium have been changed with a direct effect on soils that support plant species. The changes in cryosphere, glacier reduction and periglacial environment as glaciers retreat, decrease in the snow cover extent and earlier snowmelt, determine an effect on soils (on the structure, organic matter and humus forms, soil processes and soil types) from the top of the Alpine horizon to the bottom. The processes induced by climate change (such as erosion and tree line shifting) have a direct effect on water balance that can be observed on soil profile characters with an effect on upward migration, change in phenology, extensive losses of species. The equilibrium of the biogeochemical cycles has been changed and this has a direct effect on soils that support plant species. |
Intra-annual patterns of weather and daily radial growth changes of Norway spruce and their relationship in the Western Carpathian mountain region over a period of 2008-2012Original PaperA. Leštianska, K. Merganičová, J. Merganič, K. StřelcováJ. For. Sci., 2015, 61(7):315-324 | DOI: 10.17221/24/2015-JFS The contribution presents the results of a 5-year (2008-2012) dendroecological research in a Norway spruce (Picea abies [L.] Karst.) clone forest (Northern Slovakia). Due to different climatic and soil moisture conditions in the monitored years, different seasonal courses of stem increment formation were observed using band dendrometers with continuous data recording. The lack of precipitation affected growth processes mainly during the growth culmination and at the end of summer. The multiple regression analysis of the impact of individual factors on stem circumference changes on the basis of their partial correlation coefficients revealed that the individual environmental characteristics influenced daily stem radial changes with time lags of one to ten days. The results of the analysis of variance showed that the stem radial reactions to climatic and soil moisture factors were not significantly different between the clones. |
