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Results 361 to 390 of 740:

Considering the relationship of slope and soil loss on skid trails in the north of Iran (a case study)Original Paper

M. Akbarimehr, H. Jalilvand

J. 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.

Growth of Norway spruce (Picea abies [L.] Karsten) from artificial and natural regeneration in the Krkonoše Mts. and air temperature variabilityOriginal Paper

K. Matějka, J. Leugner

J. For. Sci., 2013, 59(4):150-158 | DOI: 10.17221/25/2012-JFS

Our research was concerned with a description of the influence of variability in average temperatures on the height growth of selected young populations of spruce in the Krkonoše Mts. Several populations of spruce were evaluated while the majority of them originated by natural regeneration on plots under disturbance of the original tree layer. In addition, several planted spruce populations in similar environmental conditions were also evaluated. The main questions of this study are as follows: is there a difference in height growth between populations of natural and artificial origin? Is it possible to find a relationship between height growth and climate feature during the last several years? The growth of young spruce populations that originated by natural regeneration was different from the growth of the planted populations. The average air temperature in the growing period, estimated as average temperature during the months of May to August, was proved to have a significant influence on year-on-year variability in spruce growth. Based on this finding, it was possible to estimate an increase in the height increment of young spruce caused by warming up since the mid-70s of the 20th century to equal approximately 16% per decade in the spruce altitudinal zone in the Krkonoše Mts.

Costs of basic methods of forest landmaintenance in protective zones of high-voltage power lines in the Czech Republic

L. Šišák

J. For. Sci., 2010, 56(1):35-41 | DOI: 10.17221/75/2009-JFS

: The paper describes the basic potential methods and their costs of maintenance of forest lands in protective zones under high-voltage power lines (HVPL) 400 kV and 220 kV. In the present situation and with available information and data, it was possible to accomplish the average cost calculations for the whole area of the Czech Republic. The paper analyses the following mechanical and chemical methods of maintenance of forest lands: full-area scrub clearing with power saw (PS), selective individual scattered clearing of trees with PS, full-area scrub clearing by milling, full-area scrub clearing by the application of herbicides and arboricides, selective individual scrub clearing of individual trees by cutting followed by spray treatment with arboricides. The maintenance of forest lands in zones of HVPL (scrub clearing) by milling belongs to the economically most convenient mechanical methods, for example when removing 3,000 trees.ha-1, the cost of this option is 20,000-23,000 CZK.ha-1ha in a period of 3-year periodic frequency, while the most expensive method is selective individual scrub clearing of scattered individual plants with PS at costs of around 84,000 CZK.ha-1.

The health and nutritional status of Norway spruce stands in the Krušné hory Mts. 15 years subsequent to the extreme winter of 1995/96Original Paper

B. Lomský, V. Šrámek, R. Novotný

J. For. Sci., 2013, 59(9):359-369 | DOI: 10.17221/37/2013-JFS

Since 1994, the nutritional status and the air pollution load have been evaluated on 20 research plots, located in young Norway spruce stands in the ridge area of the Krušné hory Mts. The most recent acute damage to the spruce stands, in the winter of 1995/96, was connected with a long-lasting inversion situation in the eastern area of the Krušné hory Mts. Today, the health status of the spruce stands, expressed in terms of the crown defoliation, has recovered and is comparable to that found in other regions of the Czech Republic. The sulphur and fluorine content of the needles has decreased significantly. The long-term negative effect of acid deposition that contributes to the degradation of forest soils remains an important part of stressors acting on forest ecosystems in the region. In recent years, nitrogen and sulphur concentrations in the needles have increased slightly again. A long-term tendency towards a decrease in the phosphorus, calcium and potassium content of the needles was detected.

Methods of digital photogrammetry in forest management in SlovakiaOriginal Paper

M. Kardoš

J. For. Sci., 2013, 59(2):54-63 | DOI: 10.17221/35/2012-JFS

The practical aspect of utilization of digital photogrammetry methods and their products in Slovak forestry is presented. We deal with the comparison of various data obtained by digital cameras, their accuracy, utilization and effectiveness for mapping. Based on presented results we summarize the main conclusions in the field of forest mapping. We also deal with the process of pan-sharpening for the preparation of image data for the interpretation and classification of forestry features. Also, the statistical characteristics of two photogrammetric projects with different geometric resolution photos (Ultracam D digital camera with ground sample distance of 10 cm and UltracamX digital camera with ground sample distance of 20 cm) from the same experimental area of the University Forest Enterprise Zvolen are described with the aim of finding an appropriate solution suitable for forest mapping. In both cases, the horizontal accuracy of the photogrammetric projects is presented. Finally, the process of true orthophoto generation and its utilization in forestry is the focus. Both experiments in this paper presented results which fulfil the accuracy standards defined by the state cadastre within the mapping of large scale maps. All projects, apart from the project of direct georeferencing, fulfilled the third accuracy class of mapping, so they can be used within cadastral mapping, land consolidations and, of course, within forested land mapping. Still, all the projects meet the accuracy requirements within the forest mapping standard, where the forestry features and forest spatial distribution units are mapped.

In vitro reproduction of rare and endemic species of rowan treeOriginal Paper

P. Máchová, J. Malá, H. Cvrčková, J. Dostál, V. Buriánek

J. For. Sci., 2013, 59(10):386-390 | DOI: 10.17221/46/2013-JFS

The preservation and reproduction of gene resources of rare and endemic rowan species were the main aims of this study. Rowan species represent important woody trees from the aspect of forest biodiversity. There are only several endemic rowan species in the Czech Republic which are of hybridogenous origin from the whitebeam (Sorbus aria) range. Most of them have been described only at the end of the 20th century. For these species, the new procedures of vegetative reproduction were developed. In vitro cultures from dormant buds of 57 mature trees were established. The successful induction of organogenesis was achieved in a MS modified medium with 0.2 mg.l-1 of BAP, 0.1 mg.l-1 of IBA, 200 mg.l-1 of glutamine, 2 mg.l-1 of glycine, 200 mg.l-1 of casein hydrolysate, 30 mg.l-1 of sucrose, and 6 mg.l-1 of agar. The pH was adjusted to 5.8. NAA in the concentration of 13.5 mg.l-1 was efficient for the rooting of microcuttings. An efficient protocol for the reproduction of endemic rowan species by means of organogenesis induction in apical meristems of dormant buds is reported.

Silvicultural strategies for adapting planted forests to climate change: from theory to practice

W.L. Mason, M. Petr, S. Bathgate

J. For. Sci., 2012, 58(6):265-277 | DOI: 10.17221/105/2011-JFS

Adapting forests to climate change involves silvicultural measures such as use of a range of species and the fostering of mixed stands. We tested these in a Sitka spruce forest in southern Scotland, employing the Ecological Site Classification to match suitability of 24 species to six climatic and edaphic variables under values of accumulated temperature and moisture deficit projected for a medium emissions scenario for the present century. Both median and 90th percentile values were contrasted. In the first case there was a small change in species suitability with Sitka spruce, noble fir, downy birch, sycamore and aspen being the most suitable species. When the 90th percentile values were employed, the suitability of Sitka spruce and similar conifers had declined by the 2050's due to soil moisture deficits. The actual performance of a range of species in a long-term experiment on a similar, warmer site showed several productive conifers including Sitka spruce that maintained reasonable growth when planted in mixture. Mixed plots were developing into pure stands of the most productive species. Species diversification was the most practical adaptation measure for this forest and should concentrate on areas of the greatest risk like south-facing slopes with free-draining soils.

Foliar nutrient status of a natural fir forest in GreeceOriginal Paper

P. Michopoulos

J. For. Sci., 2013, 59(5):191-195 | DOI: 10.17221/11/2013-JFS

The foliar nutrient status was examined in a degraded Greek fir (Abies cephalonica Loud.) forest in Mount Parnitha near Athens, Greece. The examination lied in comparing the foliar concentrations of Ca, Mg, K, N, P, Fe, Mn, Zn and Cu with the critical values referring to conifers and the elemental percentages with regard to N of the forest with the corresponding percentages of a healthy Bulgarian fir (Abies borisii regis) stand, the closest relative of the Greek fir. It was found that the needles of the Greek fir had significantly lower concentrations from the N and P critical values. Significant differences were found for the Ca/N, Mg/N, P/N, Fe/N and Mn/N percentages. Significant correlations for the Greek fir were found between needle weight and foliar N as well as between needle weight and the percentages Ca/N and Fe/N. It is highly probable that N and P in the Greek fir are in short supply.

Effect of repeated fertilization on stem growth in old stands of Pinus sylvestris in South East NorwayOriginal Paper

O. Haveraaen, L.H. Frivold

J. For. Sci., 2015, 61(2):72-79 | DOI: 10.17221/110/2014-JFS

We studied effects of repeated applications of nitrogen on stem growth of mature Scots pine at four sites with yield potential around 3 - 4.5 m3 ha‑1 yr‑1. Treatments included control (0) and fertilization with ammonium nitrate at 100 and 200 kg N ha‑1. Some plots were supplied with corresponding doses of urea. Applications were repeated up to five times, at five to twenty years intervals. Plot size was 22 x 22 m with buffer zones of 4 m. Measurements were made on an inner plot, 14 x 14 m. Tree ring widths usually reached a maximum two to four years after fertilization, returning to about the original level after seven to ten years. Responses were larger to 200 than to 100 kg N ha‑1. Annual volume increment over the experimental period was 1.5 to 2.0 m3 ha-1 larger in plots provided with 200 kg N ha-1 than in control plots, or even more as the buffer zones of 4 m did not completely exclude tree roots from growing into neighbouring plots.

Natural regeneration of senescent even-aged beech (Fagus sylvatica L.) stands under the conditions of Central Bohemia

L. Bílek, J. Remeš, D. Zahradník

J. For. Sci., 2009, 55(4):144-145 | DOI: 10.17221/823-JFS

The natural regeneration of beech (Fagus sylvatica L.) was studied under various shelterwood densities and silvicultural treatments in senescent beech stands in Central Bohemia. Four permanent research plots differed in shelterwood density, crown cover and average relative light intensities. Between 2003 and 2007, seed production, seedling emergence and survival were followed. The mean density of beech seeds (full and empty) per 1 m2 was estimated in another forest stand. In the autumn of 2003 the values were distinctly higher than those indicated for full mast years of beech. Despite high losses during the wintering of seeds, relatively low germination and high first-season mortality, the high density of 1-year-old beech seedlings indicates that these elements are not the factors which hinder natural regeneration. The thickness of the humus horizons influenced the density of young beech seedlings during all the three years. Ground vegetation was more frequent outside the crown projections of parent trees and increased with distance from the nearest tree. A reduction of crown cover to the level of 80% was an appropriate measure that assured the high survival of beech regeneration during the observed four-year period. Border cutting with the outer face oriented towards the east has to be considered as less suitable for beech regeneration than shelterwood systems and group selection harvesting.

Development of forest soils in the Krkonoše Mts. in the period 1980-2009

K. Matějka, S. Vacek, V. Podrázský

J. For. Sci., 2010, 56(11):485-504 | DOI: 10.17221/79/2010-JFS

This paper documents the development of soil conditions in the set of 32 permanent research plots in the Krkonoše (Giant) Mts. These plots represent an altitudinal gradient covering the ecosystems of beech, mixed beech-spruce and spruce stands. In all plots, representing the site conditions of the highest areas of the mountain range, standard soil pits were prepared and the soil sampling was performed in autumn of years 1980, 1993, 1998, 2003 and 2009. The results reflect extreme site conditions, soil acidification, large scale surface liming and in minor extent also different tree species composition of the stands. The general type of the soil-genesis is represented by the podzolisation, overlapping the other soil-genetic factors, including the tree species composition. Nevertheless, this development is mostly expressed in the spruce stands. The beech dominance and/or co-dominance are reflected especially by more efficient N-cycling, higher pH, S and V values and fluctuation and lower extractable Al3+ content. More efficient cycling in beech ecosystems is insignificantly documented for plant available phosphorus, calcium and magnesium contents; on the contrary higher dynamics for iron ions was registered in the spruce stands. The long-term soil dynamics with a hysteresis (evident on the base of ordination analysis) can be divided into some periods - processes of acidification (typical in the 1980's samples), liming (main effect in 1993 and 1998) and regeneration (2003, 2009). Other features, important for the soil development, are probably related to the vegetation change, but this relation is not statistically significant.

Growth of Norway spruce seedlings after transplanting into silty soil amended with biochar: a bioassay in a growth chamberShort Communication

J. Heiskanen, P. Tammeorg, R.K. Dumroese

J. For. Sci., 2013, 59(3):125-129 | DOI: 10.17221/44/2012-JFS

Biochar (BC), the carbon-rich by-product resulting from pyrolysis of biomass, is used for bioenergy and increasingly as a soil additive for carbon sequestration and soil improvement. However, information about the effects of BC on forest productivity and reforestation success, especially on boreal and temperate forest soils, is scant. We examined the effects of two BC types (Canadian and Finnish) added in proportions up to 60 vol.% into a common alluvial silty soil on the growth of transplanted Norway spruce (Picea abies [L.] Karst.) seedlings in a growth chamber. We found no marked differences in seedling growth among the binary growing media mixes used. Seedling growth attributes (seedling height, terminal shoot growth, root volume) differed consistently only between the BC types in the highest proportion used. The terminal shoot growth differed overall among the two BC types. These results suggest that BC may be applied into mineral soils without detrimental chemical effects on tree plantation success. Our results provide foundation for further field research on the longer-term impacts of adding BCs to boreal forest soils.

On the potential policy use of some selected biodiversity indicators: limitations and recommendations for improvementsShort Communication

Z. Benedek

J. For. Sci., 2014, 60(2):84-88 | DOI: 10.17221/72/2013-JFS

In order to facilitate the use of biodiversity indicators in policy making at the country level, a few and well-established indices should be suggested. Promising candidates include biodiversity-related indices of the Convention on Biological Diversity; their current use and performance are evaluated through a Hungarian case study. Especially indices of the ecosystem level have already been in use, but they are not necessarily useful measures of the state of biodiversity in their current form. For example, ecosystems suggested globally for monitoring (forests and marine habitats) are not present in all the countries, thus the way of ecosystem selection should be standardized, not the actual ecosystem types. Besides the information on the extent of some selected habitats, the original cover should also be considered to evaluate the present situation. Recommendations are demonstrated in the case study. With the use of existing data, the applicability of certain indices can be improved, but in the long run, ecosystem-based indices of the natural capital should be favoured.

Forestry and wood sector and profitability development in the wood-processing industry of the Czech RepublicOriginal Paper

V. Kupčák, Z. Šmída

J. For. Sci., 2015, 61(6):244-249 | DOI: 10.17221/113/2014-JFS

Economic viability of sustainable forest management has been included in particular forestry strategic documents since 2003. In these documents, it is stated, among other things, that economic viability is a key pillar of sustainable forest management and is of conclusive significance in preserving forests and their multiple benefits for the society. At the same time - the economic viability of sustainable forest management depends essentially on wood-producing functions of forestry. The paper aims at an identification of this key concept and at a situation analysis of economic viability under current conditions of the forestry and wood sector in the Czech Republic with a special focus on the wood-processing industry as part of the forestry and wood sector using a financial analysis.

Felling and skidding damage to residual trees following selection cutting in Caspian forests of IranOriginal Paper

F. Tavankar, B. Majnounian, A.E. Bonyad

J. For. Sci., 2013, 59(5):196-203 | DOI: 10.17221/53/2012-JFS

The felling and skidding damage to residual trees was investigated in a selectively cutting operation in the Caspian forest of Iran. The logging operation was performed by chainsaw and cable skidder. Prelogging, after felling and skidding operations residual tree injuries (species, DBH and damage) were inventoried by systematic plot sampling. Two types of tree damage were observed: destroyed and injured. In this study felling operations mainly injured trees whereas skidding was the main cause of destruction. The percentage of destroyed and injured residual trees by felling operations was 1.4% and 3.4%, whereas the percentage of destroyed and injured residual trees by skid­ding operations was 5.2% and 11.1%. About 87% of destroyed trees were found in the DBH class smaller than 22.5 cm. Maple and Alder were the most damaged trees among the other trees species. Damage to the lower bole and wood damaged intensity were the most common type of injury. To reduce the stand damage, skid trails should be planned before felling and felling directions should be predetermined. In the selection cutting management, limiting logging damage to residual trees must therefore remain a major objective.

Regeneration of forest stands on permanent research plots in the Krkonoše Mts.

S. Vacek, I. Nosková, L. Bílek, Z. Vacek, O. Schwarz

J. For. Sci., 2010, 56(11):541-554 | DOI: 10.17221/65/2010-JFS

The article describes natural, combined and artificial regeneration on 38 permanent research plots in both Czech and Polish part of the Krkonoše Mts. The attention is paid to species composition, spatial (horizontal and vertical) and age structure of forest regeneration according to different stand and site conditions. Concerning the structure and dynamics of forest stands and their regeneration, the potential and prospects of regeneration according to particular developmental stages and stand types (beech stands; mixed stands: spruce-beech, fir-beech, spruce-fir-beech; spruce stands, stands in the ecotone of the upper forest limit and relict pine woods) were evaluated. In many aspects the plots show several similarities, nevertheless the regeneration in different site and stand conditions show clear differences in dynamics of development. The main differences are result of different ecological conditions, environmental limits and biological characteristics of dominant tree species.

Toward the rational use of forest biomass: Lithuanian case study

I. Varnagiryté-Kabašinskiené

J. For. Sci., 2012, 58(10):465-471 | DOI: 10.17221/10/2012-JFS

This paper contains the information about some principles of sustainable forestry which are still relevant in the world. In 2002, Lithuania started research on the nutrient balance in forest ecosystems when the forest fuel is harvested. The consequences of the intensive forest fuel harvesting on the forest ecosystem were analysed. At the same time, the experiment on the compensatory wood ash fertilizing was established in Lithuania. After the initial calculations, having the experimental data, the Ministry of Environment of the Republic of Lithuania has initiated the preparation of the Recommendations for compensating wood ash fertilization in the forests. This review briefly systematizes and analyses the main results of the related research and some ideas for the future studies are also presented.

Free European data on forest distribution: overview and evaluationOriginal Paper

J. Trombik, T. Hlásny

J. For. Sci., 2013, 59(11):447-457 | DOI: 10.17221/58/2013-JFS

A growing need for the evaluation of prospects and sustainability of forest resources calls for the availability of harmonized data on forest distribution. We described and evaluated nine datasets providing such information: Corine LandCover, four European forest maps and four tree species distribution maps. Apart from providing a condensed overview of these datasets, we focused on the match between selected forest maps and forest management plans (FMPs) of Slovakia, which can be thought of as highly accurate information on forest distribution. The degree of match between forest and species area, within 306 forest administrative districts of Slovakia, was used as an indicator of accuracy. In addition, the match between the total forest and species area in Slovakia, given by FMPs and by evaluated datasets, was addressed. We found a high degree of match for the datasets on forest distribution (R-square 0.77-0.93, depending on the dataset), as well as strong agreement in total forest area (± 5%). Both indicators are worse in the case of forest type evaluation (coniferous and broadleaved). Poor results were obtained for tree species maps, which under- or overestimated species areas by tens of per cent, although differences were highly variable among species. The obtained results are valid mainly for temperate forests.

Land-use legacies: multi-centuries years-old management control of between-stands variability at the landscape scale in Mediterranean mountain forests, FranceOriginal Paper

S. Chauchard, F. Guibal, C. Carcaillet

J. For. Sci., 2013, 59(1):1-7 | DOI: 10.17221/42/2012-JFS

Traditional land use has shaped the Mediterranean region for a long time and has resulted in present-day complex landscapes. The land abandonment dating from the 19th century at a site located in the southwestern Alps (France) makes it possible to analyse how present-day forest stands inherit from past land uses. Tree composition and tree age structure were analysed in three stands resulting from different former land uses, i.e. ancient coppice, formerly grazed area and formerly tilled area. The ancient coppice contains the densest tree cover and is dominated by Fagus sylvatica, whereas the formerly ploughed and grazed areas are less dense, both dominated by Pinus sylvestris. Forest stand in the ancient coppice is older than in the formerly grazed area, and forest stand is the youngest in the formerly ploughed area. These stand differences are largely explained by former land use and the abandonment process. Albeit strong changes result from the land abandonment, these landscapes inherit aspects of their land use during the 19thcentury at least and the dynamics does not match the expected pattern of soil fertility.

Time consumption and productivity analysis of timber trucking using two kinds of trucks in northern IranOriginal Paper

R. Mousavi, R. Naghdi

J. For. Sci., 2013, 59(5):211-221 | DOI: 10.17221/10/2013-JFS

Increasing productivity and reducing cost in long-distance transportation have become increasingly important in the logistics of forest harvesting operations. This paper presents the research results of the performance of loading with Volvo 4500 BM and timber trucking using two types of common trucks in the Nav watershed in Iran. Both trucks can carry logs shorter than 7.8 m in length. The study used a time study based on empirical data for loads collected from one procurement district in the Nav watershed. The models included the following explanatory factors: driving distance, number of logs, and load volume. The time consumption and productivity of loading and timber trucking depends on several variables such as volume and number of logs per cycle. To evaluate the current transportation system in the Nav watershed, the empirical time study was conducted. Since transportation includes several phases and since many factors affect the work performance, significant variation in the total transportation time was observed. This makes planning and cost accounting more difficult. The models developed in the study are a promising way to support route planning and optimization, and cost and profitability calculation for trucking en­trepreneurs and the forest industry. The average productivity of log transportation was 2.84 and 3.4 m3.effective h-1 for the dump truck and chassis truck, respectively. The average hauling unit cost was 18 and 15 USD.m-3 in the dump truck and chassis truck, respectively.

Double-spined bark beetle (Ips duplicatus) (Coleoptera: Curculionidae): a new host - Douglas fir (Pseudotsuga menziesii)Short Communication

J. Kašák, J. Foit

J. For. Sci., 2015, 61(6):274-276 | DOI: 10.17221/28/2015-JFS

Spruces (Picea spp.) are considered to be the primary host trees of the double-spined bark beetle Ips duplicatus (Sahlberg, 1836), but occurrences on pines (Pinus spp.) are often reported. This paper documents the first recorded successful development of I. duplicatus on Douglas fir (Pseudotsuga menziesii) (Mirbel) Franco. Two densely infested Douglas fir trees were found in a forest dominated by Norway spruce (Picea abies) (L.) H. Karst., close to the village of Valšovice (Czech Republic). Ips duplicatus is an oligophagous species that attacks different coniferous tree species but was not previously reported to develop on Douglas fir. The infestation of Douglas fir recorded in the present study was most likely promoted by a large population of I. duplicatus in the studied region combined with a local lack of primary host trees as a consequence of bark beetle outbreak.

Forest fires and their causes in the Czech Republic (1992-2004)Original Paper

E. Kula, Z. Jankovská

J. 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.

Spatial-temporal distribution of forest fires and fire weather index calculation from 2000 to 2009 in ChinaOriginal Paper

M.R. Ullah, X.D. Liu, M. Al-Amin

J. For. Sci., 2013, 59(7):279-287 | DOI: 10.17221/8/2013-JFS

This paper describes the forest fire dynamics in the city of Sanming in Fujian province, China, from 2000 to 2009 with a view to understand the number of fires and burned areas in different counties. It also includes the spatial-temporal distribution of fires and application of the Canadian Forest Fire Danger Rating System (CFFDRS). Daily forest fire data was provided by the Department of Wildfire Prevention of Sanming Forestry Bureau. FWI calculator v.7.0.2.76 was used in this study for analysing the weather parameter data. The results showed that a total of 818 fires and burned areas of 8721.16 ha were found during the study period of 10 years. However, the highest and lowest forest fires were found in Youxi county and Sanming district, respectively. Most of the fires with large burned areas occurred at 2 p.m. Moreover, occurrences of fires were found the highest and lowest in March and June, respectively. Based on FWI calculation, the highest danger rating value was found in March, 2009. This study proposes that it would be possible to manage regular forest fire occurrences through the application of CFFDRS. Finally, to plan the fire prevention and management in southern China and other tropical countries, this system has a great opportunity for further implementations.

Analytical hierarchy process to choose the best earthwork machine in northern forests of IranOriginal Paper

A. Parsakhoo, S.A. Hosseini

J. For. Sci., 2013, 59(12):487-492 | DOI: 10.17221/44/2013-JFS

This study attempts to use the analytical hierarchy process to choose the most appropriate earthwork machine for slope classes of 30-50% and 50-70%. Required data were collected by pairwise comparison as questionnaires filled by experts of forest engineering. Results showed that cross-sections and grade line (Technical criteria), soil excavation and displacement (Environmental criteria), production rate and multi-application (Operational criteria), production cost (Economic criteria) with the respective weights of 0.345, 0.345, 0.136, 0.058, 0.058 and 0.058 were the most important criteria for choosing the earthwork machines in the slope class of 30-50%. These coefficients for the slope class of 50-70% were 0.329, 0.329, 0.174, 0.056, 0.056 and 0.056, respectively. Overall priority of bulldozer in slope classes of 30-50% and 50-70% was 0.51 and 0.48, respectively. Therefore, in slope class of 30-50% bulldozer and in slope class of 50-70% hydraulic excavator must be selected for earthwork operation.

Scolytus koenigi Schevyrew, 1890 (Coleoptera: Curculionidae): new bark beetle for the Czech Republic and notes on its biologyOriginal Paper

J. Kašák, J. Foit, O. Holuša, M. Knížek

J. For. Sci., 2015, 61(9):377-381 | DOI: 10.17221/65/2015-JFS

In November 2013, Scolytus koenigi Schevyrew, 1890 was recorded for the first time in the territory of the Czech Republic (Southern Moravia, at two localities near the village of Lednice). This finding represents the northernmost occurrence of this species in Central Europe. Because the knowledge of the S. koenigi bionomy is very limited, the characteristics of 52 galleries on 10 different host tree fragments were studied. The species was found to develop on dead or dying branches and thin trunks of maples Acer campestre L. and Acer platanoides L. with diameters of 3‒12 cm. All of the galleries comprised a 1.6-2.9 mm wide and 8-67 mm long single egg gallery oriented parallelly to the wood grain, with 18‒108 larval galleries emerging almost symmetrically on both sides of the egg gallery.

Study of briquette properties at their long-time storageOriginal Paper

M. Brožek

J. For. Sci., 2013, 59(3):101-106 | DOI: 10.17221/27/2012-JFS

The paper presents the results of laboratory tests aimed at the study of storage place, storage manner and storage time in relation to mechanical properties of briquettes made from spruce shavings. A BrikStar 50 briquetting press with a pressure chamber 65 mm in diameter of the Briklis firm was used for the briquette production. All briquettes were made at the constant adjustment of all parameters of the briquetting press. The briquette properties were evaluated by determination of their density and rupture force. Moreover, mechanical durability, gross calorific value, total mois­ture and ash content were determined. It follows from the results of tests that at briquette storage in a well closed plastic bag neither place nor storage time influenced significantly their life time. At briquette storage in a net plastic bag various intensive damage to briquettes occurred, mainly depending on their storage place and storage time.

Structure of the montane taiga forests of West Khentii, Northern Mongolia

M. Mühlenberg, J. Appelfelder, H. Hoffmann, E. Ayush, K.J. Wilson

J. For. Sci., 2012, 58(2):45-56 | DOI: 10.17221/97/2010-JFS

Studies were undertaken to investigate the composition, structure and diversity of four different types of North Mongolian montane forest near the southern border of the taiga. These forest types, classified as willow-poplar, larch-birch, spruce-fir and Siberian-pine forests, were found to be significantly different with respect to the elevational gradient. In the study area, two fire regimes could be distinguished at lower and drier elevations, frequent surface fires resulted in less diverse forests comprising coniferous species, which in their adult form were found to be fire-resistant, burn-colonizing and light-demanding deciduous tree species. In contrast, the forests colonizing the moist, higher elevations and shaded slopes had a higher diversity of tree species with greater basal area, higher proportion of deadwood, and more regenerating trees; here the coniferous shade trees experienced infrequent but destructive treetop fires. Overall, our results showed that the four forest types differed in composition according to the tree species, diameter and height classes.

Influence of vegetation on phenolic acid contents in soilOriginal Paper

J. Malá, M. Cvikrová, M. Hrubcová, P. Máchová

J. For. Sci., 2013, 59(7):288-294 | DOI: 10.17221/23/2013-JFS

The study described in this paper was undertaken in order to assess the impact of different woody plants on the dynamics of phenolic acids in soil. The influence of plant litter on the amount of phenolic compounds occurring in soils beneath several deciduous and coniferous tree species was examined in pot experiments. The contents of endogenous methanol soluble free and conjugated phenolic acids in Norway spruce, larch, rowan and two species of willow were determined. We focused on the dynamics of water-soluble and reversibly bound phenolic acid contents in the upper layers of soil substrates in pots after the cultivation of studied woody plants.

Forest visitors' opinion of recreational facilities and trails in forests in the Blaník Protected Landscape Area - a case studyOriginal Paper

A. Drábková, L. Šišák

J. For. Sci., 2013, 59(5):185-190 | DOI: 10.17221/77/2012-JFS

Currently, recreation is the most common use of protected areas and there are scarce data on the users and their opinion. The research was focused on visitors to the Blaník Protected Landscape Area (hereafter referred to as PLA), a well-known recreational area where data on visitors, important for PLA management, are missing. Therefore, the aim of the paper is find out: what kind of visitors comes to the study area; the type of forest trails and tourist facilities the visitors prefer. A questionnaire survey of forest visitors was used. Results show that the visitors mostly prefer maintained trails. According to forest visitors' opinion, the most convenient facility to place near the forest tourist trail is the nature trail panels. Furthermore, based on the acquired data, it was possible to create a visitor's profile which is important for respective research and other case studies in similar areas, and for managers of protected landscape areas to comply with both the visitors' needs and the needs of the protected area.

Effects of rubber-tired skidder and farm tractor on physical properties of soil in plantation areas in the north of IranOriginal Paper

M. Nikooy, S. Ahrari, A. Salehi, R. Naghdi

J. For. Sci., 2015, 61(9):393-398 | DOI: 10.17221/125/2014-JFS

Physical properties of soil can be affected by machines that are used for skidding which have the potential to impact soil sustainability and forest productivity. The present study evaluated the effect of timber skidding by a rubber-tired skidder and farm tractor on the soil physical properties. The study site was located in Hafdaghanan plantation region in the north of Iran. Two treatments that consisted of skidding by HSM 904 skidder and ITM285 farm tractor equipped with trailer were applied. The trails were included in three traffic levels: primary, secondary and tertiary. Treatment effects were tested using analysis of variance (ANOVA) with skidding machine types and traffic levels. Results indicated that machine type and traffic intensity are the effective factors on soil physical properties. The results showed that with an increase of traffic frequency, bulk density increased but total porosity and soil water content decreased. The results of the study provide clear evidence that farm tractor is a more environmentally friendly machine than rubber-tired skidder in the plantation area.

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