JournalTOCs

Silva Balcanica
Number of Followers: 0

This is an Open Access Journal

Open Access journal
ISSN (Print) 1311-8706
Published by Pensoft

[58 journals]

An overview of work productivity evaluation of farm tractors in timber
skidding operations
- Abstract: Silva Balcanica 23(1): 21-36
  DOI : 10.3897/silvabalcanica.23.e82383
  Authors : Mohammad Reza Ghaffariyan : Farm tractors have been applied in forest operations to carry out several tasks such as tree/felling/process-ing, forwarding, loading, skidding and cable yarding. Farm tractors can be equipped with special logging equipment that allows for their safe and efficient work in the harvesting of forest stands. This research is aimed to collect and review available literary sources on the productivity of farm tractors during skidding operations. The study results showed that work productivity of farm tractors for timber skidding has been studied by several researchers around the world. According to the results, the reported work productivity of skidding with farm tractors varied from 1.2 m3/PMH0 to 15.8 m3/PMH0 among international studies. Main variables impacting the work productivity of skidding included skidding distance, load volume, number of pieces per turn, tree diameter, tree length, slope of skid trails and engine power. Proper skid trail planning, applying suitable skidding equipment (e.g. winches, sulkies etc.), considering suitable engine size and prop-er safety standards can all help improving the work efficiency of the farm tractors during timber extracting. The information provided in this research can help the forest industry users and researchers gain proper knowledge on the work productivity of farm tractors applied for timber skidding. The study results can be also useful for planning and development purposes within small-scale forest operations. HTML XML PDF
  PubDate: Thu, 21 Apr 2022 17:31:00 +030
Dendrochronological analysis of the influence of climate on autochthonous
and introduced coniferous tree species in the city park “Prostor”,
Kardzhali
- Abstract: Silva Balcanica 23(1): 11-19
  DOI : 10.3897/silvabalcanica.23.e79249
  Authors : Dimitar Petrov Dimitrov, Miglena Zhiyanski : The study focuses on the response to climate change of indigenous and introduced coniferous tree species – Austrian black pine (Pinus nigra Arn.) and Colorado spruce (Picea pungens Engelm.) situated in the urban city park “Prostor” in the town of Kardzhali. A multifactor regression analysis was used in the frame of the dendrochronological studies to establish the functional dependence “climate – radial growth”. The model was tested in a climate window with a segment of 16 years – from 2005 to 2020. The data for air temperature and monthly precipitation amounts for Hydro-meteorological station (HMS) Kardzhali were used as predictors for the radial growth. = Both species’s indifference to the temperatures and rainfalls during the months August and September, crucial for the ring formation, leads to the absence of significant growth depressions in tree-rings chronologies and justifies the good condition of the studied trees. HTML XML PDF
  PubDate: Fri, 18 Mar 2022 17:46:00 +020
New tachinid parasitoids on pine processionary moth (Thaumetopoea
pityocampa) (Diptera: Tachinidae) in Bulgaria
- Abstract: Silva Balcanica 23(1): 5-10
  DOI : 10.3897/silvabalcanica.23.e81890
  Authors : Georgi Georgiev, Zdravko Hubenov, Plamen Mirchev, Margarita Georgieva, Maria Matova : The tachinid parasitoids (Diptera: Tachinidae) of the pine processionary moth (Thaumetopoea pityocampa) were studied in 2019 and 2020 in the Eastern Rhodopes (Fotinovo, Kandilka and Sarnak vills.), the Western Rhodopes (Dobrostan vill.) and the Struma Valley (town of Sandanski). In total, 1193 larvae and pupae of T. pityocampa were collected in 40-50-year-old Pinus nigra plantations. They were transported and observed in laboratory conditions at 20-22 °С. Three parasitoids, Compsilura concinnata, Exorista (Exorista) fasciata and Phryxe vulgaris were reared from the host. In this study, E. fasciata was established for the first time in trophic association with T. pityocampa. In addition, P. vulgaris was confirmed as a parasitoid of the host. The mortality of the pine processionary moth caused by tachinids in different localities was 0.5-5.3%, with an average of 2.6% for the country. HTML XML PDF
  PubDate: Fri, 11 Mar 2022 16:29:00 +020
Assessing the carbon stock changes in forest soils in Bulgaria
- Abstract: Silva Balcanica 22(3): 69-78
  DOI : 10.3897/silvabalcanica.22.e76252
  Authors : Lora Stoeva, Lora Kirova : Forest soils are a key element of the forest ecosystems which could contribute to carbon storage and climate change mitigation. The carbon sequestration and storage potential of the forest soils, however, depends to a great extent on the forestry operations and forest management activities carried out in the forest. There is a widely accepted assumption that under a set of climate and management conditions the carbon content in the forest soils is at equilibrium. However, different factors like management activities, productivity, decay rates and/or natural disturbances could alter the carbon dynamics of forest soils. The aim of the current study was to assess the carbon stock and the carbon stock changes in mineral forest soils in Bulgaria based on the forest soil monitoring information gathered under the ICP Forest Programme. For that purpose, a dataset from the programme on mineral forest soils from 1998 was processed and analysed. The carbon stock for each sample plot was estimated for the 0-30 cm layer. The carbon stock change was calculated for all the sample plots with repeated measurements over the study period. The results were further analysed with parametric and non-parametric statistical tests to assess whether the carbon stock changes are significant. However, the lack of other relevant observations within the monitoring implementation such as litter decomposition, turnover rates, climatic conditions, etc., hinder the application of dynamic soil carbon models in assessing and predicting the current and the future rate of the soil carbon in forests in Bulgaria. HTML XML PDF
  PubDate: Fri, 31 Dec 2021 15:41:00 +020
Spassimir Tonkov (2021): The Postglacial Vegetation History in
Southwestern Bulgaria. A Paleoecological Approach
- Abstract: Silva Balcanica 22(3): 79-79
  DOI : 10.3897/silvabalcanica.22.e80737
  Authors : Spassimir Tonkov : Book Review HTML PDF
  PubDate: Fri, 31 Dec 2021 12:25:00 +020
Morphological and physico-chemical properties of Cryosoils in the
Bulgarian antarctic base on Livingston island, Antarctica
- Abstract: Silva Balcanica 22(3): 57-67
  DOI : 10.3897/silvabalcanica.22.e66704
  Authors : Rositsa Ilieva, Rositsa Yaneva, Miglena Zhiyanski, Evgeny Abakumov : Under the global climatic changes and anthropogenic impacts on the environment, information about characteristics and specific features of soils in remote regions as Antarctica is valuable and could be used as references. This study focuses on the analyses of original data about the physico-chemical composition and micromorphological structure of Cryosols, collected in 2019 from the sampling area of the Bulgarian Antarctic Base “St. Kl. Ohridski” located on Livingston Island, Antarctica. The studied Cryosols are moderately acidic with slow and incomplete transformation of organic residues. The organic carbon content is low, except for soils formed under the influence of an ornithogenic factor. The mezo- and micromorphological observations show a predominance of the mineral phase, weakly affected by weathering processes. Many soil pores and voids are observed, which facilitates water-air and intra-soil exchange during the short Antarctic summer. The analyses showed an evidence for the connection of the processes of soil formation of Cryosols in the region with the pulsating degradation of the glaciers. HTML XML PDF
  PubDate: Wed, 29 Dec 2021 17:34:00 +020
Acute toxicity of Galium odoratum to the freshwater cladoceran Moina
macrocopa
- Abstract: Silva Balcanica 22(3): 49-55
  DOI : 10.3897/silvabalcanica.22.e77816
  Authors : Mariam Bozhilova : Galium odoratum (L.) is a medicinal plant with a number of health benefits, used in traditional and modern medicine. The toxicity of the coumarin in Galium odoratum is classified as high, however, no experimental data or data on toxic effects in humans following intake of Galium odoratum are available. The potential toxic effect can be estimated based on the content of coumarin and knowledge of its toxicity.The aim of the current study is to evaluate the acute toxicity effects of a range of concentrations of Galium odoratum water extract on Moina macrocopa and calculate the LC50 within 24 hours. In order to compare the toxicity with those of other, well-known and widely used medicinal plants, extracts of Matricaria chamomilla and Tribulus terrestris are also tested. The results show that LC50 value of Galium odoratum is comparable with those of Matricaria chamomilla and Tribulus terrestris, and Galium odoratum has intermediate toxicity between the two other studied species. HTML XML PDF
  PubDate: Wed, 29 Dec 2021 08:43:00 +020
First record, new cultivated host and host plant preference of the
invasive oak lace bug (Corythucha arcuata Say, 1832) (Heteroptera:
Tingidae) in Transcarpathia (West Ukraine)
- Abstract: Silva Balcanica 22(3): 41-48
  DOI : 10.3897/silvabalcanica.22.e76231
  Authors : Antal Nagy, Kálmán Szanyi, Tímea Szalárdi, Szabolcs Szanyi : Oak lace bug (Corythucha arcuata) has continuously spread through Europe since its appearance in 2000, and it has become a dangerous pest of Quercus species in most countries. Despite of its high abundance in the surrounding countries it was found in West Ukraine only in 2020. During our investigation carried out in 2020 OLB was detected in all studied large forest patches of the Ukrainian part of the Carpathian Lowland. These were one of the newest distribution data from Ukraine after its appearance in the far coast of Black See near Yalta (South Ukraine). OLB most live on Q. robur and Q. petraea but in an orchard located near an infested forest patch we found infested sweet cherry (P. avium) trees, which is a new, formerly not mentioned cultivated host of the pest. HTML XML PDF
  PubDate: Tue, 21 Dec 2021 08:59:00 +020
Green roofs – good regulatory practices with potential to be applied in
Bulgaria and North Macedonia
- Abstract: Silva Balcanica 22(3): 29-39
  DOI : 10.3897/silvabalcanica.22.e75511
  Authors : Mariam Bozhilova, Miglena Zhiyanski, Biljana Stojanova, Plamen Glogov : Green roofs are used worldwide to mitigate the impacts of extensive urbanization, bringing benefits on social, economic, and environmental levels. In order to promote and facilitate the construction of green roofs by private investors, many countries have developed specific legislative requirements and incentives. However, there still are countries where the construction of green roofs is not properly addressed in the legislation, and where no incentive mechanisms are developed. The good practices in three European countries, leaders in regards to the implementation of green roofs – the Netherlands, Belgium, and Germany, are analyzed in this article. A variety of incentives is introduced to accelerate the construction of green roofs. Different requirements are also set to ensure that the roofs will be designed and maintained to provide the desired benefits. The existing local regulations in Bulgaria and North Macedonia were analyzed as well. The only incentive in Bulgaria is the possibility of reducing the legally required green area by compensating it with a green roof. In North Macedonia, no legislative documents or incentives related to green roofs were found.The regulations, applied in the Netherlands, Belgium, Germany, and other countries can be used as good practice examples, modified, and applied from the authorities of countries that still have not developed their own, in order to motivate the investors and facilitate the construction of green roofs. HTML XML PDF
  PubDate: Thu, 16 Dec 2021 09:57:00 +020
Biological control of gypsy moth (Lymantria dispar) by the
entomopathogenic fungus Entomophaga maimaiga in Bulgaria in 2021
- Abstract: Silva Balcanica 22(3): 17-27
  DOI : 10.3897/silvabalcanica.22.e78600
  Authors : Georgi Georgiev, Plamen Mirchev, Margarita Georgieva, Mihail Kechev, Sevdalin Belilov, Maria Matova, Vyara Petrova, Petya Mateva, Maria Kirilova, Ilian Mutafchiiski : In 2021, biological control programme against gipsy moth (Lymantria dispar) populations was carried out by introduction of the entomopathogenic fungus Entomophaga maimaiga on the territory of four State Forest Enterprises: Municipal Enterprise (ME) ‘Management of Municipal Forests, Agriculture and Forestry’, Nessebar; State Game Enterprises (SGE) Nessebar and Balchik; State Forestry (SF) Vidin. The pathogen was introduced during the period 15-26.03.2021 in 34 localities - five in ME Nessebar, eight in SGE Nessebar, ten in SGE Balchik and eleven in SF Vidin. The average number of gypsy moth population density in the locations of introduction was relatively high, ranging between 0.4-15.9 egg mass/tree in the area of SGE Balchik and 11.9-65.0 egg mass/tree in the area of ME Nessebar. The average mortality of young gypsy moth caterpillars (first-third instar) due to E. maimaiga varied between 2.6% (SGE Balchik) and 13.0% (SF Vidin), and of caterpillars in later fourth-sixth instar - between 20.7% (SF Vidin) and 52.4% (ME Nessebar). The overall mortality of the gipsy moth caterpillars due to E. maimaiga was lowest in the region of SGE Balchik (26.1%), followed by SF Vidin (33.7%), SGE Nessebar (48.5%) and ME Nessebar (55.9%). As a result of the introduction, gipsy moth severe outbreaks in the region of Nessebar was significantly suppressed. The high number of E. maimaiga resting spores persists in the surface layers of the soil in the other two areas (Vidin and Balchik) has the potential to suppress L. dispar attacks in next years. HTML XML PDF
  PubDate: Tue, 14 Dec 2021 07:46:00 +020
New data on the distribution and host plants of subfamily Buprestinae
(Coleoptera: Buprestidae) in Bulgaria
- Abstract: Silva Balcanica 22(3): 5-12
  DOI : 10.3897/silvabalcanica.22.e77434
  Authors : Vladimir Sakalian, Enrico Migliaccio, Victor Gashtarov, Danail Doychev, Georgi Georgiev : Data about the distribution and host plants of 47 species group taxa from subfamily Buprestinae are presented. In this study, three localities of Anthaxia (Anthaxia) suzannae were reported for the first time in Bulgaria. In addition, Paliurus spina-christi was established as a new host plant for Chrysobothris leonhardi. HTML XML PDF
  PubDate: Fri, 10 Dec 2021 07:41:00 +020
Biotic factors damaging forest stands in Gornata Koria and Chuprene
Reserves in Western Balkan Range, Bulgaria
- Abstract: Silva Balcanica 22(2): 91-102
  DOI : 10.3897/silvabalcanica.22.e77233
  Authors : Margarita Georgieva, Georgi Georgiev, Plamen Mirchev, Gergana Zaemdzhikova, Danail Doychev, Sonya Bencheva, Nikolay Zafirov, Stelian Dimitrov, Martin Iliev, Vladislav Trenkin : Assessment and monitoring of health status in deteriorated forest stands in Gornata Koria and Chuprene Reserves in Western Balkan Range (Bulgaria) were conducted in 2017. An integrated approach (based on remote sensing technologies and terrestrial validation) was applied. A series of subsequent terrain observations were carried out in both protected areas mainly in dead or in poor health status stands. As a result, sixteen insect species were identified in Gornata Koria and nine pests in Chuprene Reserves. The predominant number of pests included bark beetles and weevils (Curculionidae), longhorn beetles (Cerambycidae), etc. Attacks caused by the European bark beetle (Ips typographus) formed the main disturbance in the Norway spruce forests in both reserves. Ten parasitic and ten saprophytic fungi were identified in the stands of the Norway spruce (Picea abies), silver fir (Abies alba) and European beech (Fagus sylvatica). Among the parasitic fungi, six species were identified as destructive (Armillaria sp., Heterobasidion annosum, Fomitopsis pinicola, Fomes fomentarius, Ramaria flava and Pholiota squarrosa). HTML XML PDF
  PubDate: Fri, 19 Nov 2021 15:32:00 +020
Three species of bark beetles (Coleoptera: Curculionidae, Scolytinae) on
Pinus peuce in Pirin Mountains in Bulgaria
- Abstract: Silva Balcanica 22(2): 69-72
  DOI : 10.3897/silvabalcanica.22.e73436
  Authors : Sevdalin Belilov, Georgi Georgiev, Plamen Mirchev, Margarita Georgieva : In 2020 and 2021, three species of bark beetles (Coleoptera: Curculionidae, Scolytinae) were established on Macedonian pine (Pinus peuce) in the region of Vihren hut in Pirin Mts. Branches, damaged by snow were collected and studied in laboratory conditions. As a result, 24 specimens of Ips amitinus were reared in 2020 and 81 specimens of I. amitinus, Crypturgus pusillus and Pityogenes chalcographus in 2021. The most abundant species was I. amitinus with 75.2%, followed by P. chalcographus (21.9%) and C. pusillus (2.9%). HTML XML PDF
  PubDate: Wed, 20 Oct 2021 17:00:00 +030
New data on the taxonomy and distribution of subfamily Polycestinae
(Coleoptera: Buprestidae) in Bulgaria
- Abstract: Silva Balcanica 22(2): 73-79
  DOI : 10.3897/silvabalcanica.22.e74151
  Authors : Vladimir Sakalian, Enrico Migliaccio, Victor Gashtarov, Danail Doychev, Georgi Georgiev : Data on the distribution of 13 species group taxa of subfamily Polycestinae in Bulgaria are presented. Taxonomic notes about two species, Acmaeodera (Acmaeotethya) octodecimguttata and Acmaeodera (Acmaeotethya) degener, which allow their differentiation, are also given. HTML XML PDF
  PubDate: Wed, 20 Oct 2021 12:15:00 +030
Predicting productivity of timber loading operations: a literature review
- Abstract: Silva Balcanica 22(2): 81-90
  DOI : 10.3897/silvabalcanica.22.e69240
  Authors : Mohammad Reza Ghaffariyan : Loading is considered a bottleneck of the forest harvesting system as it acts as a connection between primary transport and secondary transport (from roadside/ landing to mills or central yards). Any delay during the loading component can cause delay in the primary wood extraction and/ or secondary transportation. This article reviewed the current knowledge on loading productivity studies. Based on the results, the main variables impacting the loading productivity include log size, log lengths, load volume per truck, number of logs (or pieces) per truck and number of safety straps. The productivity of loading operations ranged from 3.4 m3/PMH0 in a manual loading to 168.9 m3/PMH0 using mechanised loaders. The results of this review can assist the academic and industrial users for predicting, controlling and managing the productivity of loading operations. HTML XML PDF
  PubDate: Wed, 20 Oct 2021 11:53:00 +030
Challenges of assessment and mapping of ecosystem services in Bulgarian
(Rhodope) and Russian (Altai) mountain protected areas in the context of
post-socialist transformations and new conservation paradigms
- Abstract: Silva Balcanica 22(2): 43-68
  DOI : 10.3897/silvabalcanica.22.e69861
  Authors : Dmitry V. Chernykh, Maria Glushkova, Dmitry K. Pershin, Miglena Zhiyanski, Alina E. Zinovieva, Dmitry V. Zolotov, Lilia F. Lubenets, Roman Yu. Biryukov : The overarching goal of this survey was to identify the challenges of ecosystem services assessment and mapping in Russian and Bulgarian mountain protected areas in the context of post-socialist transformations, new conservation paradigms and climate change. The Altai Mountains in Russia and the Rhodope Mountains in Bulgaria were selected as key mountain territories for comparison due to their similar characteristics: agriculture, forest exploitation, tourism activities, etc. Both in Bulgaria and in Russia, perceptions of the protected areas functioning have been changing, facilitated by global shifts. Thus, the concept of ecosystem services has now been actively introduced in nature and biodiversity conservation policies. Based on WDPA data the emergence of different types of protected areas in Russia and Bulgaria was determined. Key problems of assessment and mapping of ecosystem services in Russian and Bulgarian mountain protected areas were recognised, mainly related to the shortage and quality of baseline data. At the same time, there were also some specifics for the two countries due to their size and national legislation. Like many other mountainous regions in the world, the Rhodopes in Bulgaria and the Altai Mountains in Russia are flagships in the improvement of nature conservation strategies. These regions often participate in a variety of international conservation programmes and are constantly expanding the range of protected areas. It is generally accepted that the Altai Mountains and the Rhodopes are not only centres of biodiversity richness in their countries, but also hotspots of a variety of ecosystem services. HTML XML PDF
  PubDate: Wed, 20 Oct 2021 07:23:00 +030
Insect pests and their role as biocontrol agents on populations of
Impatiens glandulifera in Bulgaria – a case study
- Abstract: Silva Balcanica 22(2): 33-41
  DOI : 10.3897/silvabalcanica.22.e72662
  Authors : Gergana Zaemdzhikova, Plamen Glogov : Based on data from available scientific publications, a review of the insects, trophically related to Impatiens glandulifera in its European invasion zone has been made. As a result, nine insect species (Pristerognatha fuligana, Deilephila elpenor, Xanthorhoe biriviata, Chrysolina herbacea, Siobla sturmi, Impatientinum asiaticum, Aphis fabae, Aphis nasturtii, Phytoliriomyza melampyga) were found on the invasive plant. Of the identified insects, seven species (D. elpenor, X. biriviata, A. fabae, A. nasturtii, C. herbacea, P. fuligana, P. melampyga) are widespread in the country, of which only two – C. herbacea and P. fuligana are associated with I. glandulifera. The remaining two (I. asiaticum and S. sturmi) are not pre-sented in the Bulgarian entomofauna. Тhe potential role of these insects as agents of biological control of populations of I. glandulifera in Bulgaria has been assessed. HTML XML PDF
  PubDate: Fri, 8 Oct 2021 07:13:00 +0300
A short review on studies on work productivity of mechanical tree planting
- Abstract: Silva Balcanica 22(2): 25-32
  DOI : 10.3897/silvabalcanica.22.e64233
  Authors : Mohammad Reza Ghaffariyan : Reforestation can be carried out using natural regeneration or artificial regeneration. There are vari-ous methods for the artificial regeneration, including manual planting, mechanical planting and aerial/or ground seeding. This article aimed to review the current reports on the productivity of mechanical planting to provide a summary of productivity rates for the planting machines. According to the review’s results, mechanical planting productivity may vary from 143 to 475 seedlings per productive machine hours depending on the machine type, environment (such as surfaces obstacles and stoniness) and the operator experience. Employing skilled operators and selecting suitable worksites can help increasing the work productivity. Integrating and optimising the whole planting chain, from the nursery to the plant-ing phase, can assist also with reducing the cost and improving the productivity. As mechanical planting machines get more widely adopted in different countries, their overall efficiency will improve over time. HTML XML PDF
  PubDate: Tue, 5 Oct 2021 08:35:00 +0300
Possible benefits from greening of public transport stops in Sofia,
Bulgaria
- Abstract: Silva Balcanica 22(2): 17-24
  DOI : 10.3897/silvabalcanica.22.e69245
  Authors : Mariam Bozhilova, Miglena Zhiyanski : Public transport shelters provide an unused surface that can be utilized in various ways, including for unconventional landscaping. The benefits from greening of public transport shelters are insufficiently studied and unutilized. The article evaluates some of the benefits which may result from the construction of green public transport shelters in the central part of Sofia.There are a total of 2780 aboveground public transport stops in Sofia. In the surveyed area are located 257 stops, 150 of which currently have shelters. The potential of greened shelters to remove PM10 and CO2 from the ambient air is estimated for several different scenarios. If 250 public transport shelters are entirely greened (roof and 3 walls) with Festuca sp., the removed PM10 will be about 20 kg/yr, or 0.01% of the yearly emissions of PM10 from transport in the surveyed area. The sequestered CO2 will be 17047.3 kg /yr., or approximately the CO2 emitted by 40 diesel cars with an average daily mileage of 10 km per day for a year. The reduction of PM10 and CO2 is not significant, however, in a big city with intensive construction and a constantly increasing population, every possibility for greening needs to be explored. Green stops may be used in combination with other measures. Proper selection of plant species and design solutions maximizing the green surface will increase the benefits. HTML XML PDF
  PubDate: Tue, 27 Jul 2021 10:25:00 +030
Factors affecting Thaumetopoea pityocampa emergence in laboratory
conditions
- Abstract: Silva Balcanica 22(2): 5-15
  DOI : 10.3897/silvabalcanica.22.e66436
  Authors : Plamen Mirchev, Margarita Georgieva, Georgi Georgiev, Gergana Zaemdzhikova, Maria Matova, Viara Petrova : To investigate the factors affecting the emergence of the pine processionary moth (Thaumetopoea pityocampa) in laboratory conditions, a number of 1487 larvae, prepupae and pupae were collected in the period February-May 2019 from five pest habitats: Fotinovo and Kandilka villages (inhabited by a summer phenological form), Sandanski and Klisura towns (winter phonological form occurs) and Sarnak village (both forms occur). At the date of collection, the rate of parasitism was very low (0-0.1%). Throughout the study, significant differences in the characteristics of pupal stage and mortality between both phenological forms were established. The rate of emerged adults varied from 21.4% to 77.6% in the observed habitats. The sex ratio between female and male specimens was almost equal. Only 0.6% of samples emerged in the second year, after diapause. In four localities (Fotinovo, Kandilka, Sandanski and Sarnak), the rate of infection by entomopathogens was between 6.0% and 20.8%, and the parasitism caused by tachinids – between 0.9% and 3.4%. The flight period of the summer and winter phenological forms of T. pityocampa were clearly differentiated with about a month. In summer form, the flight began in late May and ended in the last decade of June, and in winter form – from early July to the end of August. The duration of the flight period in both forms lasted 30 to 50 days with an equal number of emerged male and female specimens. HTML XML PDF
  PubDate: Tue, 15 Jun 2021 10:26:00 +030
Review of studies on motor-manual felling productivity in eucalypt stands
- Abstract: Silva Balcanica 22(1): 77-87
  DOI : 10.3897/silvabalcanica.22.e58750
  Authors : Mohammad Reza Ghaffariyan : Globally, about 20 million ha of land area is occupied by plantations of Eucalyptus. Motor-manual tree harvest-ing techniques (using chainsaws) are still applied in eucalypt plantations, especially in difficult terrains or for large- sized trees where mechanised felling may not be an effective and safe possible option to apply. There is little information available on motor-manual felling in eucalypt stands. This article reviewed available literature on the productivity of motor-manual felling. The results were classified into four regions, including Africa, Asia/Oceania, America and Europe. Results of international studies indicate that the main factors impacting the productivity of motor-manual felling include diameter at the breast height (DBH), travelling distance to trees, understory density and terrain slope. Operator experience also plays a key role in felling operations. The range of reported productivity varied from 0.6 m3/PMH0 to 48.9 m3/PMH0 in different regions. This article provides key recommendations on improving motor-manual felling productivity, which can provide a guide for sustainable harvesting planning purposes. HTML XML PDF
  PubDate: Fri, 19 Mar 2021 10:00:07 +020
Forest Long-legged flies (Diptera: Dolichopodidae) from the park of the
Forest Research Institute with new records for Bulgaria and notes on
habitat affinity
- Abstract: Silva Balcanica 22(1): 67-75
  DOI : 10.3897/silvabalcanica.22.e62052
  Authors : Mihail Kechev, Plamen Glogov : The paper gives information for 17 dolichopodid species collected from the park of the Forest Research Institute, Sofia. Two species (Lamprochromus kowarzi and Syntormon pseudospicatum) are recorded as new for the fauna of Bulgaria. Habitat preferences of the identified species are discussed. Two species dominate the study area: Hercostomus nanus dominates from early June to mid-July and then Sybistroma obscurellus dominates from mid-July to the second half of October. HTML XML PDF
  PubDate: Fri, 19 Mar 2021 10:00:06 +020
Effect of wastewater sludge treatment on early growth and physiological
responses of willow (Salix spp.) and poplar (Populus spp.) pot-grown
plants
- Abstract: Silva Balcanica 22(1): 57-65
  DOI : 10.3897/silvabalcanica.22.e58528
  Authors : Ivaylo Tsvetkov, Nikolina Tzvetkova, Svetla Marinova : Combining biomass production from fast-growing woody species with wastewater treatment is an attractive concept from the economic, energy and environmental points of view. A pilot experiment on study-ing the effect of wastewater treatment on the early growth and initial physiological responses of willow and poplar plants was carried out in greenhouse conditions. The survival, height growth, net photosyn-thesis, stomatal conductance and transpiration of two hybrid clones of black poplar (Populus x euroameri-cana (Dode) Guinier) (I-214 and I-45/51) and white willow (S. alba L.) pot-grown plants treated with different doses of agrochemically characterised wastewater sludge were studied during the establishment year. The height growth and number of resprouted willow shoots were also measured during the second year after cutting, at the end of the vegetation season. While the early growth height of poplar clones was markedly affected by the clone origin and wastewater sludge treatment, the latter did not considerably influence the height of the willow plants either during the establishment and the following year, but essentially increased the number of resprouted shoots during the second vegetation season. The rate of CO2 assimilation of willow plants was significantly influenced by the wastewater sludge treatment, with plants grown at the higher doses displaying higher photosynthetic performance. The application of wastewater sludge had no essential impact on the values of the physiological parameters of the poplar plants, but particular responses were found among the clones. HTML XML PDF
  PubDate: Fri, 19 Mar 2021 10:00:05 +020
Economics of forest biomass for bioenergy: potential site preparation
savings from coarse woody harvesting residue removal in a short-rotation
Eucalyptus globulus (Labill.) plantation
- Abstract: Silva Balcanica 22(1): 45-55
  DOI : 10.3897/silvabalcanica.22.e58636
  Authors : Martin Strandgard, Mathieu Béland : The study used time studies and cost analysis to assess potential economic benefits from site preparation cost reductions resulting from producing coarse woody harvesting residue (CWHR) for bioenergy. In contrast, previous studies have predominantly used anecdotal estimates of site preparation costs.The study was performed in a recently clearfelled 15-year-old plantation of Eucalyptus globulus (Labill) in Tasmania, Australia. The study area consisted of the control area (0.51 ha), containing ~35 m3 ha-1 of CWHR and the CWHR harvest area (2.47 ha), containing ≤12 m3 ha-1 of CWHR. The control area had been harvested with a harvester – forwarder system, which left all harvesting residue (HR) onsite, where-as the CWHR harvest area had been harvested with a feller-buncher – skidder – processor system which removed most of the HR. The latter site was used to simulate an area where CWHR had been harvested. The study examined productivities and costs of machines performing site preparation in each area. The preparation of the control area site was performed with an excavator that windrowed CWHR, fol-lowed by a skidder-mounted plough constructing planting furrows. Residual CWHR post-windrowing was
  PubDate: Fri, 19 Mar 2021 10:00:04 +020
Comparison of tree diameter distributions in managed and unmanaged
Kazdağı fir forests
- Abstract: Silva Balcanica 22(1): 31-43
  DOI : 10.3897/silvabalcanica.22.e58020
  Authors : Ferhat Kara : Forest structural complexity affects tree growth, species diversity, understory seedling density, wildlife habitat and fire behaviour. Thus, defining the structural complexity of forest ecosystems would play a crucial role in their management. The vertical structure in stands of shade-tolerant tree species can be described by using the distribution of tree diameters. In this study, the main objective was to determine and compare the diameter distribution patterns of managed and unmanaged Kazdağı fir (Abies nordmanniana subsp. equi-trojani) forests in northern Turkey. Hierarchical clustering analysis was used to define the diameter distribution patterns. Three main diameter distribution patterns were examined in both managed and unmanaged forests. Two of the patterns in the managed forest did not possess the expected diameter structure of selection silviculture (i.e. reverse J-shape). The observed patterns in the unmanaged forest were mostly representative of the diameter structure of old-growth forests. Given the initial findings, it is likely that the small-scale disturbances created by selection methods may not be adequate to establish and recruit sufficient number of trees into small- diameter sizes in Kazdağı fir forests. The assessment of patterns of tree diameter distribution in these forests would create a basis for future research, aiming to enhance the structural complexity. HTML XML PDF
  PubDate: Fri, 19 Mar 2021 10:00:03 +020
Biofertlizer Lumbrical improves the growth and ex vitro acclimatization of
micropropagated pear plants
- Abstract: Silva Balcanica 22(1): 17-30
  DOI : 10.3897/silvabalcanica.22.e57661
  Authors : Nataliya Dimitrova, Lilyana Nacheva, Małgorzata Berova, Danuta Kulpa : In vitro micropropagation of plants is highly useful for obtaining large quantities of planting material with valuable economic qualities. However, plantlets grow in vitro in a specific environment and the adaptation after the transfer to ex vitro conditions is difficult. Therefore, the acclimatization is a key step, which mostly determines the success of micropropagation. The aim of this investigation was to study the effect of the biofertlizer Lumbrical on ex vitro acclimatization of micropropagated pear rootstock OHF 333 (Pyrus communis L.). Micropropagated and rooted plantlets were potted in peat and perlite (2:1) mixture with or without Lumbrical. They were grown in a growth chamber at a temperature of 22±2 °C and photoperiod of 16/8 hours supplied by cool-white fluorescent lamps (150 µmol m-2 s-1 Photosynthetic Photon Flux Density, PPFD). The plants were covered with transparent foil to maintain the high humidity, and ten days later, the humidity was gradually decreased. Biometric parameters, anatomic-morphological analyses, net photosynthetic rate and chlorophyll a fluorescence (JIP test) were measured 21 days after transplanting the plants to ex vitro conditions. The obtained results showed that the plants, acclimatized ex vitro in the substrate with Lumbrical, presented better growth (stem length, number of leaves, leaf area and fresh mass) and photosynthetic characteristics as compared to the control plants. This biostimulator could also be used to improve acclimatization in other woody species HTML XML PDF
  PubDate: Fri, 19 Mar 2021 10:00:02 +020
First records of a potentially new plant community from the ruderal
vegetation in the Black Sea Coast, Bulgaria
- Abstract: Silva Balcanica 22(1): 5-15
  DOI : 10.3897/silvabalcanica.22.e56860
  Authors : Plamen Glogov, Mira L. Georgievа : The paper presents the first data of an unreported plant community dominated by Hordeum leporinum Link and Bituminaria bituminosa (L.) Stirt. (class Stellarietea mediae R. Tx., Lohmeyer et Preising in R.Tx. 1950). It is currently established in four localities in the region of the Black Sea coast, between the town of Ravda and the town of Nessebar, Bulgaria. Among the characteristic features of the community are: (i) it occupies places with an active human presence near the beach; (ii) preferences for shallow san-dy or rocky soils; (iii) Bituminaria bituminosa (L.) Stirt. as a dominant, diagnostic and constant species for the community. Other diagnostic species for the association are Anchusa officinalis L., Malva sylves-tris L., Sonchus arvensis L. and Avena fatua L. (iv) annual and perennial species have an equal participa-tion in the community; (v) increased presence of diagnostic species for the class Artemisietea vulgaris Lohmeyer et al. ex von Rochow 1951. Phytogeographically, the species composition of the community has a strong Mediterranean influence. In close proximity to its reléves there are always communities of xerophytic shrubs or low trees (in many cases alien species, such as Amorpha fruticosa L., Ziziphus jujuba Mill. and Robinia pseudoacacia L.) that participate in the association without forming a full second layer (their cover abundance is less than 30%). HTML XML PDF
  PubDate: Fri, 19 Mar 2021 10:00:01 +020