Pub Date : 2023-02-28DOI: 10.3897/silvabalcanica.24.e101560
Stanimira Shuleva, V. Gagov, P. Zhelev
Seed orchards are an important source of seeds with improved genetic quality. Here we present results of a study on the genetic composition of seed orchards crop of Austrian black pine (Pinus nigra Arn.). Two seed orchards were included in the study – a clonal seed orchard established near Sliven, and a seedling seed orchard, established in the region of Simitli. The outcrossing rates were higher in the clonal seed orchard (Sliven), 0.873 and 0.806 multi-locus (tm) and single-locus (ts) estimates, respectively. The same values were 0.623 and 0.530, respectively, in the seedling seed orchard (Simitli). The inbreeding coefficient was positive in both cases, but was significantly different from zero in the clonal seed orchard only (0.101 vs. 0.032). Thus, the two studied seed orchards demonstrate different genetic efficiency. The results are discussed in relation to seed orchard management and efficiency.
种子园是改良遗传品质种子的重要来源。本文报道了奥地利黑松(Pinus nigra Arn.)种子园作物遗传组成的研究结果。该研究包括两个种子园-一个在Sliven附近建立的无性系种子园和一个在Simitli地区建立的幼苗种子园。无性系种子园(Sliven)的异交率较高，多位点(tm)和单位点(ts)分别为0.873和0.806。在苗木种子园(Simitli)，同样的值分别为0.623和0.530。两种情况下近交系数均为正(0.101比0.032)，但单株种子园近交系数与零差异显著。因此，所研究的两个种子园表现出不同的遗传效率。研究结果与种子园管理和效益有关。
{"title":"Outcrossing rates in two seed orchards of Pinus nigra Arn. in Bulgaria","authors":"Stanimira Shuleva, V. Gagov, P. Zhelev","doi":"10.3897/silvabalcanica.24.e101560","DOIUrl":"https://doi.org/10.3897/silvabalcanica.24.e101560","url":null,"abstract":"Seed orchards are an important source of seeds with improved genetic quality. Here we present results of a study on the genetic composition of seed orchards crop of Austrian black pine (Pinus nigra Arn.). Two seed orchards were included in the study – a clonal seed orchard established near Sliven, and a seedling seed orchard, established in the region of Simitli. The outcrossing rates were higher in the clonal seed orchard (Sliven), 0.873 and 0.806 multi-locus (tm) and single-locus (ts) estimates, respectively. The same values were 0.623 and 0.530, respectively, in the seedling seed orchard (Simitli). The inbreeding coefficient was positive in both cases, but was significantly different from zero in the clonal seed orchard only (0.101 vs. 0.032). Thus, the two studied seed orchards demonstrate different genetic efficiency. The results are discussed in relation to seed orchard management and efficiency. ","PeriodicalId":52662,"journal":{"name":"Silva Balcanica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48739805","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-28DOI: 10.3897/silvabalcanica.24.e101383
P. Mirchev, G. Tsankov, M. Georgieva, G. Zaemdzhikova, M. Matova, G. Georgiev
Studies on egg parasitoids of the pine processionary moth (Thaumetopoea pityocampa) were conducted during the period 1991-2018 in native localities of the pest on the Balkan Peninsula and in Asia Minor. In Bulgaria the biological material (2510 egg batches and 579273 eggs) was collected in 48 host localities. A number of 650 egg batches and 135611 eggs were studied from the Balkan countries (North Macedonia, Bosnia and Herzegovina, Albania and Greece), and in the Asian part of Turkey (Asia Minor), the biological material was examined from nine habitats. Eight species of egg parasitoids (Ooencyrtus pityocampae, Baryscapus servadeii, B. transversalis, Pediobius bruchicida, Anastatus bifasciatus, Eupelmus vesicularis, E. vladimiri and Trichogramma sp.) were found. The total regulating effect of egg parasitoids in Bulgaria was on average 17.6%, and in the other Balkan countries – 24.9%. Trichogramma sp. was found in 63.1% of the analysed samples in Bulgaria and in 55.6% from the neighboring countries. The percent of parasitism of T. pityocampa eggs by Trichogramma sp. was low - on average 0.39% for Bulgaria and 0.73% for the other Balkan countries. The relative share of the species in the total percentage of parasitised eggs for Bulgaria and the other countries was 2.2% and 2.9%, respectively.
{"title":"A review of Trichogramma Westwood parasitoids on eggs of Thaumetopoea pityocampa (Denis & Schiffermüller) in habitats of the Balkan Peninsula and Asia Minor","authors":"P. Mirchev, G. Tsankov, M. Georgieva, G. Zaemdzhikova, M. Matova, G. Georgiev","doi":"10.3897/silvabalcanica.24.e101383","DOIUrl":"https://doi.org/10.3897/silvabalcanica.24.e101383","url":null,"abstract":"Studies on egg parasitoids of the pine processionary moth (Thaumetopoea pityocampa) were conducted during the period 1991-2018 in native localities of the pest on the Balkan Peninsula and in Asia Minor. In Bulgaria the biological material (2510 egg batches and 579273 eggs) was collected in 48 host localities. A number of 650 egg batches and 135611 eggs were studied from the Balkan countries (North Macedonia, Bosnia and Herzegovina, Albania and Greece), and in the Asian part of Turkey (Asia Minor), the biological material was examined from nine habitats. Eight species of egg parasitoids (Ooencyrtus pityocampae, Baryscapus servadeii, B. transversalis, Pediobius bruchicida, Anastatus bifasciatus, Eupelmus vesicularis, E. vladimiri and Trichogramma sp.) were found. The total regulating effect of egg parasitoids in Bulgaria was on average 17.6%, and in the other Balkan countries – 24.9%. Trichogramma sp. was found in 63.1% of the analysed samples in Bulgaria and in 55.6% from the neighboring countries. The percent of parasitism of T. pityocampa eggs by Trichogramma sp. was low - on average 0.39% for Bulgaria and 0.73% for the other Balkan countries. The relative share of the species in the total percentage of parasitised eggs for Bulgaria and the other countries was 2.2% and 2.9%, respectively. ","PeriodicalId":52662,"journal":{"name":"Silva Balcanica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48099872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-27DOI: 10.3897/silvabalcanica.24.e101297
G. Georgiev, M. Georgieva, P. Mirchev, Sevdalin Belilov, G. Zaemdzhikova, M. Matova
The pine processionary moth (Thaumetopoea pityocampa) was reported for the first time in North Bul-garia in 2022. Winter nests of the pest were observed in a number of pine plantations in more than 10 sites of four Forest State Enterprises (Troyan, Sevlievo, Gabrovo, Plachkovtsi). The penetration of the pest into the new localities is due to a long-distance dispersion by vehicles. In January 2023, the nests in new localities contained fifth-instar larvae of T. pityocampa. Only about 3% of them were empty as larvae had descended in the soil for pupation. Based on the high population density and presence of old nests in some localities, it was assumed that the pest penetrated into Northern Bulgaria most likely 3-4 years ago.
{"title":"First penetration of pine processionary moth (Thaumetopoea pityocampa) in North Bulgaria","authors":"G. Georgiev, M. Georgieva, P. Mirchev, Sevdalin Belilov, G. Zaemdzhikova, M. Matova","doi":"10.3897/silvabalcanica.24.e101297","DOIUrl":"https://doi.org/10.3897/silvabalcanica.24.e101297","url":null,"abstract":"The pine processionary moth (Thaumetopoea pityocampa) was reported for the first time in North Bul-garia in 2022. Winter nests of the pest were observed in a number of pine plantations in more than 10 sites of four Forest State Enterprises (Troyan, Sevlievo, Gabrovo, Plachkovtsi). The penetration of the pest into the new localities is due to a long-distance dispersion by vehicles. In January 2023, the nests in new localities contained fifth-instar larvae of T. pityocampa. Only about 3% of them were empty as larvae had descended in the soil for pupation. Based on the high population density and presence of old nests in some localities, it was assumed that the pest penetrated into Northern Bulgaria most likely 3-4 years ago. ","PeriodicalId":52662,"journal":{"name":"Silva Balcanica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46097681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-24DOI: 10.3897/silvabalcanica.24.e101192
Elena Todorova, M. Zhiyanski, Leonid Todorov
The present study is focused on examining the changes of key weather parameters using detailed daily data for the period 1985-2021 in an area of interest situated in Rila mountain in Bulgaria which is a territory that is prone to wildfires. Using this long-term horizon, the research defines the main climate factor trends and relates them with real events of wildfires by using the Angström index and statistical methods with focus on outlining specific weather conditions that indicate fire risk. As a result, the Angström index was proven to be a reliable source for determining the potential weather conditions for fire occurrence in the area of interest, part of protected area BG0000496 Rilski manastir. Low relative humidity was identified as the main factor influencing fire occurrence in the reviewed real wildfire events. Specific range and behavior of the key weather parameters, influencing wildfire occurrence were detected. These findings could be a good source of information when elaborating a forest fire prevention system and may help for appropriate prioritization of factors and management of resources.
{"title":"Using high precision climate data for wildfire risk assessment","authors":"Elena Todorova, M. Zhiyanski, Leonid Todorov","doi":"10.3897/silvabalcanica.24.e101192","DOIUrl":"https://doi.org/10.3897/silvabalcanica.24.e101192","url":null,"abstract":"The present study is focused on examining the changes of key weather parameters using detailed daily data for the period 1985-2021 in an area of interest situated in Rila mountain in Bulgaria which is a territory that is prone to wildfires. Using this long-term horizon, the research defines the main climate factor trends and relates them with real events of wildfires by using the Angström index and statistical methods with focus on outlining specific weather conditions that indicate fire risk. As a result, the Angström index was proven to be a reliable source for determining the potential weather conditions for fire occurrence in the area of interest, part of protected area BG0000496 Rilski manastir. Low relative humidity was identified as the main factor influencing fire occurrence in the reviewed real wildfire events. Specific range and behavior of the key weather parameters, influencing wildfire occurrence were detected. These findings could be a good source of information when elaborating a forest fire prevention system and may help for appropriate prioritization of factors and management of resources.","PeriodicalId":52662,"journal":{"name":"Silva Balcanica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44826128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-20DOI: 10.3897/silvabalcanica.23.e84213
L. Sarvananda, P. Fernando, P. Palihaderu, Amal D. Premarathna
In the contemporary generation, rapid urbanization, industrialization, and declining woodland lead to global weather modifications. The massive scale of deforestation for firewood, constructions, paper products, textile, and plenty of different packages are steadily enforcing a critical poor impact on the surroundings. Inherently, plant cellulose has restrained utility because of the presence of hemicellulose and lignin. Consequently, studies in the discipline of microbial cellulose display many benefits over plant cellulose. It possesses numerous crucial and unique properties compared to plant cellulose, including high purity, better absorptivity, excellent polymerization, crystallization, in-situ mold potential, biodegradability, biocompatibility, and plenty of others. This assessment looks into a potent cellulose producer to develop an economically feasible manner for huge-scale production of microbial cellulose therefore, it may replace some of the requirements where plant cellulose has been currently in use.
{"title":"Microbial cellulose: an alternate source for plant cellulose","authors":"L. Sarvananda, P. Fernando, P. Palihaderu, Amal D. Premarathna","doi":"10.3897/silvabalcanica.23.e84213","DOIUrl":"https://doi.org/10.3897/silvabalcanica.23.e84213","url":null,"abstract":"In the contemporary generation, rapid urbanization, industrialization, and declining woodland lead to global weather modifications. The massive scale of deforestation for firewood, constructions, paper products, textile, and plenty of different packages are steadily enforcing a critical poor impact on the surroundings. Inherently, plant cellulose has restrained utility because of the presence of hemicellulose and lignin. Consequently, studies in the discipline of microbial cellulose display many benefits over plant cellulose. It possesses numerous crucial and unique properties compared to plant cellulose, including high purity, better absorptivity, excellent polymerization, crystallization, in-situ mold potential, biodegradability, biocompatibility, and plenty of others. This assessment looks into a potent cellulose producer to develop an economically feasible manner for huge-scale production of microbial cellulose therefore, it may replace some of the requirements where plant cellulose has been currently in use.","PeriodicalId":52662,"journal":{"name":"Silva Balcanica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47329572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-20DOI: 10.3897/silvabalcanica.23.e97628
V. Sakalian, G. Georgiev
New data on the distribution of 12 species and subspecies of ground beetles (Coleoptera: Carabidae), which belong to 9 genera, 6 tribes and 5 subfamilies (Anthiinae, Carabinae, Cindelinae, Dryptinae and Panagaeinae) in Kenya are reported.
{"title":"New data on the distribution of ground beetles (Coleoptera: Carabidae) in Kenya","authors":"V. Sakalian, G. Georgiev","doi":"10.3897/silvabalcanica.23.e97628","DOIUrl":"https://doi.org/10.3897/silvabalcanica.23.e97628","url":null,"abstract":"New data on the distribution of 12 species and subspecies of ground beetles (Coleoptera: Carabidae), which belong to 9 genera, 6 tribes and 5 subfamilies (Anthiinae, Carabinae, Cindelinae, Dryptinae and Panagaeinae) in Kenya are reported.","PeriodicalId":52662,"journal":{"name":"Silva Balcanica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42713943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-20DOI: 10.3897/silvabalcanica.22.e98314
G. Georgiev, M. Georgieva, Sevdalin Belilov, P. Mirchev, Stanko Deliyanchev, Velizar Mladenov, Kadir Kropov, Sirma Haydarova
Strong winds uprooted more than 100 thousand m3 of coniferous trees in natural forest stands nearby the town of Smolyan (the Western Rhodopes) in January 2018. Although damaged trees were quickly removed from the stands, the European spruce bark beetle (Ips typographus) attacked the healthy Norway spruce trees near the windthrow areas in August 2020. Our hypothesis was that the trees were infested by the pest in previous years when no symptoms of attacks were observed. This study was conducted in three spruce stands, located near the windthrow areas and attacked by I. typographus, and in three control (healthy) stands located 5-10 km from the affected areas. We used satellite images captured by Sentinel-2 in September 2017-2020. It was established that in September 2017 (a year before the windthrow), the mean values of the Normalized difference vegetation index (NDVI) in the attacked stands were concentrated between 0.60 and 0.75 (with a maximum at 0.70), indicating that the trees were in good health. During the period 2018-2020 the distribution of mean values of NDVI was stretched between 0.35 and 0.75, which is an indication of evidence of pest attacks on the individual trees. The detail comparison of pixel values of the NDVI in the attacked and control sample plots was made on the base of images captured on 27.06.2020. The mean NDVI values in the three control plots (0.74-0.79) were much higher than the mean values in the sample plots attacked by the pest (0.57-0.65). These results showed that the values of NDVI based on satellite remote sensing data of Sentinel-2 can be used for early detection of I. typographus infestations in spruce stands around the windthrows. These data are important for rapid planning and implementing the sanitary feelings that reduce the pest population.
{"title":"Early detection of Ips typographus infestations by using Sentinel-2 satellite images in windthrow affected Norway spruce forests in Smolyan region, Bulgaria","authors":"G. Georgiev, M. Georgieva, Sevdalin Belilov, P. Mirchev, Stanko Deliyanchev, Velizar Mladenov, Kadir Kropov, Sirma Haydarova","doi":"10.3897/silvabalcanica.22.e98314","DOIUrl":"https://doi.org/10.3897/silvabalcanica.22.e98314","url":null,"abstract":"Strong winds uprooted more than 100 thousand m3 of coniferous trees in natural forest stands nearby the town of Smolyan (the Western Rhodopes) in January 2018. Although damaged trees were quickly removed from the stands, the European spruce bark beetle (Ips typographus) attacked the healthy Norway spruce trees near the windthrow areas in August 2020. Our hypothesis was that the trees were infested by the pest in previous years when no symptoms of attacks were observed. This study was conducted in three spruce stands, located near the windthrow areas and attacked by I. typographus, and in three control (healthy) stands located 5-10 km from the affected areas. We used satellite images captured by Sentinel-2 in September 2017-2020. It was established that in September 2017 (a year before the windthrow), the mean values of the Normalized difference vegetation index (NDVI) in the attacked stands were concentrated between 0.60 and 0.75 (with a maximum at 0.70), indicating that the trees were in good health. During the period 2018-2020 the distribution of mean values of NDVI was stretched between 0.35 and 0.75, which is an indication of evidence of pest attacks on the individual trees. The detail comparison of pixel values of the NDVI in the attacked and control sample plots was made on the base of images captured on 27.06.2020. The mean NDVI values in the three control plots (0.74-0.79) were much higher than the mean values in the sample plots attacked by the pest (0.57-0.65). These results showed that the values of NDVI based on satellite remote sensing data of Sentinel-2 can be used for early detection of I. typographus infestations in spruce stands around the windthrows. These data are important for rapid planning and implementing the sanitary feelings that reduce the pest population.","PeriodicalId":52662,"journal":{"name":"Silva Balcanica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45171853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-20DOI: 10.3897/silvabalcanica.22.e96504
Eli Pavlova-Traykova
One of the most vulnerable to soil erosion parts in Bulgaria is the Struma river watershed. In the past, a lot of erosion control activities have been carried out in this catchment, but the topographic condition and easily prone to soil erosion soils are still redounding to erosion processes. As a global problem with severe effects on the environment, soil erosion is on the agenda of scientific community. Because of difficult recognition on time, various methods for erosion risk and sediment loss assessment were applied. For mountainous watersheds one of the most appropriate approach is Erosion Potential Model (EPM). The study aims to evaluate soil erosion and investigate its spatial distribution by applying EPM, also known as Gavrilovic method. The object of investigation is the upper part of the Dzherman river, which is tributary of Struma river. The method was implemented only for forest territories to determine the most vulnerable part of the forest. The results showed that for the forest territories the average value of the coefficient Z is 0.19, which defines erosion as “low” and the average soil loss only for forest areas is 15.28 m3/km2/year. Nevertheless there are territories with more than 100 m3/km2/year.
{"title":"using the epm method for the estimation of soil erosion in forest territories in the upper part of Dzherman River","authors":"Eli Pavlova-Traykova","doi":"10.3897/silvabalcanica.22.e96504","DOIUrl":"https://doi.org/10.3897/silvabalcanica.22.e96504","url":null,"abstract":"One of the most vulnerable to soil erosion parts in Bulgaria is the Struma river watershed. In the past, a lot of erosion control activities have been carried out in this catchment, but the topographic condition and easily prone to soil erosion soils are still redounding to erosion processes. \u0000 As a global problem with severe effects on the environment, soil erosion is on the agenda of scientific community. Because of difficult recognition on time, various methods for erosion risk and sediment loss assessment were applied. For mountainous watersheds one of the most appropriate approach is Erosion Potential Model (EPM).\u0000 The study aims to evaluate soil erosion and investigate its spatial distribution by applying EPM, also known as Gavrilovic method. The object of investigation is the upper part of the Dzherman river, which is tributary of Struma river. The method was implemented only for forest territories to determine the most vulnerable part of the forest. The results showed that for the forest territories the average value of the coefficient Z is 0.19, which defines erosion as “low” and the average soil loss only for forest areas is 15.28 m3/km2/year. Nevertheless there are territories with more than 100 m3/km2/year. ","PeriodicalId":52662,"journal":{"name":"Silva Balcanica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47220638","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-20DOI: 10.3897/silvabalcanica.23.e96802
Svetozar Madzhov
In the present study the main numerical characteristics of the reliability indicators for the Komatsu SAA4D104E-1 engines of the KOMATSU WB93R-5 backhoe loader have been determined, and the laws of resource allocation have been established. To study the level of reliability of machines, a methodology for experimental research has been developed, where the complex, comparative and formal methods, as well as the systematic, cybernetic and statistical approach have been used. It has been found that increasing the level of reliability of the engine elements can be improved by increasing the quality and timeliness of the repair and maintenance activities and compliance with the rules of operation. This study is a continuation of a study conducted by the author.
{"title":"Study on the level of operational reliability of diesel engines for backhoe loaders","authors":"Svetozar Madzhov","doi":"10.3897/silvabalcanica.23.e96802","DOIUrl":"https://doi.org/10.3897/silvabalcanica.23.e96802","url":null,"abstract":"In the present study the main numerical characteristics of the reliability indicators for the Komatsu SAA4D104E-1 engines of the KOMATSU WB93R-5 backhoe loader have been determined, and the laws of resource allocation have been established.\u0000 To study the level of reliability of machines, a methodology for experimental research has been developed, where the complex, comparative and formal methods, as well as the systematic, cybernetic and statistical approach have been used. It has been found that increasing the level of reliability of the engine elements can be improved by increasing the quality and timeliness of the repair and maintenance activities and compliance with the rules of operation.\u0000 This study is a continuation of a study conducted by the author.","PeriodicalId":52662,"journal":{"name":"Silva Balcanica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42914007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-20DOI: 10.3897/silvabalcanica.22.e95109
K. Petkova, E. Molle, Aysel Mustafova
Two provenance tests in North-Eastern Bulgaria have been studied, whose purpose is to test the response of beech provenances from Southern Germany to the drier and warmer climatic conditions in Bulgaria, in order to predict how they would perform in a warming and drying climate. The provenance tests were established in the spring of 2010 in the area of the Varbitza and Kipilovo Forest Services with 2-year-old seedlings in a 2 x 1 m scheme in 3 replications. Four provenances of common beech were studied - 2 German (Silberbach and Ebersdorf) and 2 Bulgarian (Petrohan and Berkovitza). On the 12th year after afforestation, an inventory and measurements of the height and root collar diameter were carried out. The results were processed statistically by applying one and two-factor analysis of variance, as well as Tukey’s test for multiple comparisons. A higher survival rate was found in the provenance test in Kipilovo. The Bulgarian provenances Petrohan and Berkovitza were characterized by better growth in height in both provenance tests, and in root collar diameter - provenance Petrohan. Provenance Ebersdorf could be recommended for use in drier and warmer places in Southern Germany.
{"title":"Survival and growth of Common beech (Fagus sylvatica L.) provenances in North-Eastern Bulgaria","authors":"K. Petkova, E. Molle, Aysel Mustafova","doi":"10.3897/silvabalcanica.22.e95109","DOIUrl":"https://doi.org/10.3897/silvabalcanica.22.e95109","url":null,"abstract":"Two provenance tests in North-Eastern Bulgaria have been studied, whose purpose is to test the response of beech provenances from Southern Germany to the drier and warmer climatic conditions in Bulgaria, in order to predict how they would perform in a warming and drying climate. The provenance tests were established in the spring of 2010 in the area of the Varbitza and Kipilovo Forest Services with 2-year-old seedlings in a 2 x 1 m scheme in 3 replications. Four provenances of common beech were studied - 2 German (Silberbach and Ebersdorf) and 2 Bulgarian (Petrohan and Berkovitza). On the 12th year after afforestation, an inventory and measurements of the height and root collar diameter were carried out. The results were processed statistically by applying one and two-factor analysis of variance, as well as Tukey’s test for multiple comparisons. A higher survival rate was found in the provenance test in Kipilovo. The Bulgarian provenances Petrohan and Berkovitza were characterized by better growth in height in both provenance tests, and in root collar diameter - provenance Petrohan. Provenance Ebersdorf could be recommended for use in drier and warmer places in Southern Germany.","PeriodicalId":52662,"journal":{"name":"Silva Balcanica","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48851016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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