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PRODUCTIVITY MODELS AND COSTS OF COMBINED SKIDDER - HARVESTER IN CONIFEROUS FORESTS
 

Stanimir Stoilov*, Georgi Angelov, Svetlin Aladzhov, and Pavel Nichev

Dept. of Technologies and mechanization in forestry, University of Forestry, 10 St. Kliment
Ohridski Blvd., 1797 Sofia, Bulgaria. E-mail: stoilovs@ltu.bg
 

Abstract:

In addition to natural pine forests in Bulgaria, there are also large artificial plantations (over 1.5 million ha), created in the period of 1950-1990. Large areas with non-thinned coniferous plantations located at low altitudes are associated with a high probability of reduced growth and significant health problems. Traditionally, adapted agricultural tractors are the most widely used equipment for timber extraction in Bulgaria. The shortage of work force due to labor-intensive and unattractive logging work is one of the reasons for making efforts to introduce more advanced, multipurpose equipment. However, in Bulgaria the use of harvesters is limited by the predominance of deciduous forests, steep terrains and by the maximum allowed harvesting intensity of 30 %. The latter requirement often makes modern logging equipment unprofitable. In an attempt to overcome some of these limitations, the use of a combined wheeled skidder-harvester (SH) has been introduced in the eastern Rhodopes Mountains in the last few years. The SH works as a harvester and fells the accessible trees located on the skid roads and on the corridors. The remaining marked trees are felled manually by chainsaw. The felled trees are dragged to the machine by a two-drum winch equipped with a remote control, skidded to the landing where they are delimbed, bucked and piled by the SH. The mean productivity of the SH which stands for a mean skidding distance of 69 m, a mean bunching distance of 14 m, a mean load volume of 4.06 m3, was estimated at 9.38 m3.PMH-1 (8.27 m3.SMH-1) timber piled at landing, which is comparable to two typical logging teams with adapted tractors and 4-5 workers in each team. The gross costs per unit done by the SH (14.24 €.m-3) are within the regional level for coniferous stands.

(Forestry Ideas, 2021, Vol. 27, No. 1) [Download]
Downloads: 15

STATISTICAL JUSTIFICATION OF THE REQUIRED SAMPLES’ SIZE OAK SAWN TIMBER BATCH
 

Heorhiy H. Hrynyk(1), Leonid S. Osadchuk(1), Liubov M. Kondratiuk(1), Olena M. Hrynyk(1), Volodymyr M. Gryb(2), Victoriia I. Melnyk(2)*, and Artur F. Likhanov(2)
 

1. Ukrainian National Forestry University, 103 Gen. Chuprynky Str., Lviv 79057, Ukraine.
E-mails: h.hrynyk@nltu.edu.ua; l.osadchuk@nltu.edu.ua; l.kondratiuk@nltu.edu.ua;
o.hrynyk@nltu.edu.ua
2. National University of Life and Environmental Sciences of Ukraine, 15 Heroyiv Oboronyst Str., Kyiv 03041, Ukraine. E-mails: gvm1958@nubip.edu.ua; nti_dep@nubip.edu.ua*;
likhanov.bio@gmail.com
 

Abstract:

The task of the study is to establish and justify the required amount of sawn timber, which must be measured to determine the conformity of the entire batch of sawn wood to the specified size on the basis of statistical processing of a sample of sawn timber from the total batch. It is established that the batch is homogeneous in width and thickness, and differs in length of a sawn timber. The values of variation coefficients for length of a sawn timber are much lower than similar values for thickness and width. Given the nature of the grouping of sawn timber particles around the central stage in terms of thickness, width and length, it can be argued that the samples are similar. Student’s t-test was used at the p-level to check the difference between the mean values of individual samples. Measurement error (ME) for almost all indicators of the studied sawn timber is in the range of 0.1-5.0 %, which indicates that the experiment was performed with sufficient accuracy. In fact, 144 units of lumber were selected from 5 packages, which is more than 125 of the minimum required to establish the batch conformity of size and quality characteristics. Using the values of SE, ME and SD, calculated for individual samples, it was found that to correctly determine the deviations, including measurement accuracy and appropriate moisture content errors, it is sufficient to use from each individual sample no more 24 pieces of the appropriate sawn timber types. Using the recommendations for checking the conformity of sample to acceptable quality level for the total batch of a sawn timber, which was 2207 pcs in 5 packages, was confirmed the sufficiency of usage of the sample of 125 pieces from 5 packages.

(Forestry Ideas, 2021, Vol. 27, No. 1) [Download]
Downloads: 12

FLORISTIC ANALYSIS OF PLANT COMMUNITIES WITH THE PARTICIPATION OF A NARROW TIEN SHAN ENDEMIC, TARAXACUM KOK-SAGHYZ L.E.RODIN
 

Anna A. Ivashchenko(1), Nashtay Mukhitdinov(2), Karime T. Abidkulova(2)*,
Abibulla Ametov(2), Alexander Tashev(3), and Alibek Ydyrys(4)
 

1. Department of Entomology, Institute of Zoology, al-Farabi Ave. 93, Almaty,
050060 Kazakhstan. E-mail: ivashchenkoanna64@gmail.com
2. Department of Biodiversity and Bioresorces, al-Farabi Kazakh National University,
al-Farabi ave. 71, Almaty, 050040 Kazakhstan. E-mails: nashtay41@gmail.com;
karime.abidkulova@kaznu.kz*; abibullaametov43@gmail.com; Ydyrys.Alibek@gmail.com
3. Department of Dendrology, University of Forestry, 10, Kliment Ochridsky Blvd.,
Sofia, Bulgaria. E-mail: altashev@abv.bg
4. Department of Biophisics, Biomedecine and Neuroscience, al-Farabi Kazakh National
University, al-Farabi ave. 71, Almaty, 050040 Kazakhstan. E-mail: Ydyrys.Alibek@gmail.com
 

Abstract:


Taraxacum kok-saghyz L.E.Rodin is a promising natural rubber source and an alternative to Hevea brasiliensis (Willd. ex A. Juss.) Mull.Arg. At the same time, T. kok-saghyz is a narrow endemic and a rare species with decreasing population size due to degradation of its natural habitat. Therefore, it is listed in the Red Data Book of Kazakhstan. Despite a large number of studies addressed various characteristics of this plant, the data on the floristic composition of plant communities it is part of are limited. The aim of our studies was to assess the floristic composition of plant communities with the participation of T. kok-saghyz. The article presents the most complete, up-to-date list of the flora comprising 169 species belonging to 110 genera and 35 families. We present the results of an analysis including taxonomic, chorological and ecological data, identified the basic spectrum consisting of 29 species which are the most characteristic indicators of the plant communities studied. For the first time, the ‘core’ of the flora was determined, consisting of 14 species. According to the habitat type, most of the basic spectrum was formed by mountain species (14) including one narrow endemic (Ketmentau), followed by Palaearctic species (8). According to ecological preferences, the following groups were distinguished: mesophytes (9 species), mesoxerophytes (7 species), and halophytes of various types (9 species). The share of species preferring saline habitats (halophytes) was 31.4 %. The most similar (Koch’s index of biotal dispersity of 23.1 %) were communities at the western border of the surveyed area, and the value of the index gradually decreased towards the eastern border (from 22.7 % to 18.7 %). The results obtained can be important in the further studies on the populations of T. kok-saghyz, in searching for potential habitats and organizing population monitoring. 

(Forestry Ideas, 2021, Vol. 27, No. 1) [Download]
Downloads: 17

FOSTERING THE SUSTAINABILITY OF COMMUNITY FORESTRY PROGRAM: CASE STUDY IN LAMPUNG-SUMATRA
 

Christine Wulandari(1), Samsul Bakri(2)*, Melya Riniarti(1),
and Supriadi Supriadi(3)
 

1. Forestry Department and Graduate Program of Forestry, Faculty of Agriculture, University
of Lampung, Jl. Soemantri Brojonegoro # 1, Bandar Lampung, 35145, Indonesia.
E-mails: christine.wulandari@fp.unila.ac.id, chs.wulandari@gmail.com
2. Forestry Department and Graduate Program of Environmental Science, University of Lampung, # 1 Jalan Soemantri Brojonegoro, Bandar Lampung, 35145, Indonesia.
*E-mail: samsul.bakri@fp.unila.ac.id
3. Way Seputih-Sekampung Watershed Management Unit, Ministry of Environment and Forestry of Republic Indonesia, Bandar Lampung, Indonesia.
 

Abstract:

Community Forestry Program in Indonesia (called HKm: Hutan Kemasyarakatan) as the scheme for recovering forest degradation from encroachment has been operating for 13 years now, but until nowadays there is no available guideline for fostering its sustainability (SUST). HKm Authority, however, still have 22-24 years remain to foster the program before the scheme due. It is in needing both economic and tree biodiversity indicators of every HKm’s member land as the guidance for sustaining the program. The income as the economic indicator itself is commonly affected by the endogenous and exogenous variables. This research aimed at determining the roles of: (i) endogenous and exogenous variables on income agroforestry yield (INCM), (ii) INCM on tree biodiversity performance (BIODV), and (iii) BIODV on the HKm’s SUST. Data collected by interviewing 230 members of HKm Jaya Lestari located in Way Kanan Regency-Lampung, Indonesia in February-May 2018. These HKm members consisted of four ethnic groups which the two are as the native (Semendonese and Lampungese) that more adaptive to agroforestry cultivation, whereas the remains (Javanese and Sundanese) are the offspring of people moved from Java Island under colonization program by Dutch Administration since 1905. We employed Ordinary Least Square regression postulate model to investigate the first purpose and Loglinear Regression to examine the second and the third purposes. Minitab Version 16 software was applied for the models’ goodness-fits test and parameter optimization at 90 and 95% confident level. The research suggests: (i) endogenous variables with positive effect on INCM were the family size, participation in extension activities, land  holding acreage, the tribes whose Sundanese and Semendonese were higher than Javanese, and with negative effect was the land elevation; whereas the exogenous variable affected negatively the rural facility construction and nursery demonstration plot activities; (ii) the higher INCM the higher BIODV, but (iii) the better BIODV the lower SUST will be. For the sake of pursuing SUST, it recommends to continue fostering HKm members by managing the endogenous variables in order to rise up INCM, and then multiply BIODV as well as to broaden HKm members’ awareness on voluntary planting some wooden trees that have been adaptive or endemic at local region such as iron wood (Fagraea fragrans Roxb), cinnamon (Cinnamomum verum J. Presl), and Shorea javanica.

(Forestry Ideas, 2021, Vol. 27, No. 1) [Download]
Downloads: 9

INFLUENCE OF WILDFIRE ON SOIL MICROBIAL COMMUNITY AND CHEMICAL PARAMETERS IN DOLNA BANIA REGION, BULGARIA
 

Boyka Malcheva(1)* and Emiliya Velizarova(2)

1. Soil Science Department, University of Forestry, 10 K. Ohridski Blvd., 1797 Sofia, Bulgaria. *E-mail: boika.malcheva@gmail.com
2. Ministry of Environment and Water, 22 Maria Louiza Blvd., 1000 Sofia, Bulgaria.
E-mail: velizars@abv.bg
 

Abstract:

Microbial indicators of forest soils affected by forest fire under conifers (Pinus sylvestris L., Larix desidua Mill.) and mixed (Pinus sylvestris L., Quercus cerris L.) forests from north slopes of Rila Mountain (Dolna Bania region) have been examined 7 days after a wildfire occurrence. An increased quantity of total microflora in the upper (0-5 cm) layer of fire-affected soil in comparison with that taken from a control (unburned) sampling site was established due to the rise of soil temperature and pH, accompanied with a simultaneous decrease in soil humidity. Results show the highest proportion of the analysed microflora represented by non-spore-forming bacteria, bacilli, bacteria assimilating mineral nitrogen. The quantity of Actinomycetes and Micromycetes decreased in soil affected by fire. The predominant groups of microorganisms (ammonifying and nitrifying bacteria) play an important role at different stages of mineralization processes of the organic matter in fire-affected soil.

(Forestry Ideas, 2021, Vol. 27, No. 1) [Download]
Issues: 1-5 | 6-10 | 11-15 | 16-20 | 21-23