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Tytuł:
Porównanie metod szacowania pozyskaniowych szkód glebowych na przykładzie rębnego drzewostanu bukowego
A comparison of methods to estimate harvest-induced damage to the soil using the example of a beech timber stand
Autorzy:
Kulak, D.
Powiązania:
https://bibliotekanauki.pl/articles/1312645.pdf
Data publikacji:
2014
Wydawca:
Instytut Badawczy Leśnictwa
Tematy:
lesnictwo
drzewostany bukowe
pozyskiwanie drewna
ciecia rebne
zrywka drewna
szkody w lesie
gleby lesne
warstwa wierzchnia
uszkodzenia gleby
szacowanie szkod
metody szacowania szkod
logging damage
indicators of soil damage
beech timber stand
agricultural tractor
Opis:
The study determines the extent of soil disturbances occurring during mechanised harvesting operations in a beech timber stand and investigates whether applying different research methods can be used to classify, in a comparable way, forest areas with different levels of soil damage. In the analysed stand, felling and on-site processing were conducted with chainsaws, while extracting – using an farm tractor. After the completion of logging operations, visible soil disturbances on each sample plot were measured, including their area, volume and depth, and the value of five most common indicators of soil damage was calculated. The share of disturbed surface area, the volume of soil disturbances and different soil damage indicators allowed sample plots to be arranged in the same way according to increasing levels of soil damage occurring during harvesting. A different order was observed only in relation to the depth of the ruts formed. The similarity of the applied measures and classifications of soil disturbances indicates that all of the methods can be applied to make simple comparisons of the degree of soil damage. Because field trials are easy to perform, soil damage indicators based on a visual assessment of soil condition, without the need to take measurements, are worth recommending at first. A fuller picture of the level and nature of detected soil damage, however, can be obtained by taking into account the depth of the disturbance.
Źródło:
Leśne Prace Badawcze; 2014, 75, 3; 245-251
1732-9442
2082-8926
Pojawia się w:
Leśne Prace Badawcze
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kosztochłonność pozyskania drewna harwesterem w drzewostanach przebudowywanych z zastosowaniem cięć częściowych
Cost effectiveness of timber harvest with a harvester in the stands rebuilt under the shelterwood system
Autorzy:
Szewczyk, G.
Kulak, D.
Powiązania:
https://bibliotekanauki.pl/articles/991507.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
drzewostany przebudowywane
pozyskiwanie drewna
koszty
wydajnosc pracy
dzien roboczy
maszyny lesne
harwestery
harwester Silvatec 8266 TH Sleipner
timber harvest
felling
cost
productivity
Opis:
Paper presents the results of research on the productivity and economic effectiveness of timber harvesting in stands managed under complex cutting systems. Use of the operating time of a work−shift, including wood processing, loads preparation for skidding and changes at work sites, was low and amounted to 0.62. The main categories of the operating time were delimbing (45%) and travelling (31%). The unit costs of work of a harvester in the analysed stands were higher amounting to 69 PLN/m³ for eight−hour shifts and 110 working days a year, and 40 PLN/m 3 for sixteen−hour shifts compared to the work of the saw operator (32 PLN/m³ for the eight−hour shift).
Źródło:
Sylwan; 2013, 157, 04; 243-252
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ wybranych środków zrywkowych na uszkodzenia gleby w rębnych drzewostanach bukowo - jodłowych
The impact of selected skidding techniques on soil damage in beech-fir timber stands
Autorzy:
Kulak, D.
Barszcz, A.
Powiązania:
https://bibliotekanauki.pl/articles/1013081.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
gleby lesne
warstwa wierzchnia
oddzialywanie na glebe
zrywka drewna
uszkodzenia gleby
drzewostany bukowo-jodlowe
lesnictwo
skidery
zrywka ciagnikiem
zrywka konna
skidding
soil damage
horse
skidder
farm tractor
Opis:
The extent and structure of topsoil damage caused by different skidding techniques, like horse, skidder and farm tractor operating together, were determined. The research was carried out during the final cuts in the beech−fir stands situated in the foothill zone. The smallest extent of damage was caused by horse skidding (15% of stand area), while the largest – by skidder (18%). At the same time, the highest volume of disturbed soil (40 m3/ha) characterised horse skidding while the lowest (30 m3/ha) was observed when all the three skidding techniques were used. Analysis of the dimensions (area and volume) of single soil disturbances showed the smallest damage caused by skidder. The larger area and volume of disturbed soil was characteristic for the joint use of the three different skidding techniques. The research showed that soil damage caused by horse skidding was twice less likely than if skidder was used and over 2.5 times more probable if skidding was performed by several techniques.
Źródło:
Sylwan; 2008, 152, 12; 20-28
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rozmiar i charakter naruszeń wierzchniej warstwy gleby powstałych podczas pozyskiwania drewna w trzebieżowym drzewostanie jodłowym
Size and character of the damage to the top soil layer caused during harvest in a thinned fir stand
Autorzy:
Kulak, D.
Seńczyszyn, L.
Powiązania:
https://bibliotekanauki.pl/articles/1008885.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
drzewostany jodlowe
trzebieze
pozyskiwanie drewna
zrywka drewna
oddzialywanie na glebe
gleby lesne
warstwa wierzchnia
uszkodzenia gleby
damage from timber extraction
early thinning
fir stand
farm tractor
Opis:
The paper depicted size and character of the disturbances in top soil layer in a fir stand after early thinning. The treatment was performed in summer using engine−driven chain saws and a farm tractor with a skidding trailer. Size of topsoil damage was confirmed to be very low, with the value of Ug index below 1.5%. In the experiment, the probability analysis of topsoil disturbances showed their decline with the growing distance from the skid road.
Źródło:
Sylwan; 2011, 155, 08; 509-517
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Uszkodzenia drzew i odnowienia w wyniku trzebieży wczesnych w wybranych drzewostanach jodłowych
Damage to trees and advence growth resulting from early thinnings in selected fir stands
Autorzy:
Stanczykiewicz, A.
Kulak, D.
Powiązania:
https://bibliotekanauki.pl/articles/882663.pdf
Data publikacji:
2014
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Leśny Zakład Doświadczalny. Centrum Edukacji Przyrodniczo-Leśnej w Rogowie
Tematy:
lesnictwo
drzewostany jodlowe
trzebiez wczesna
pozyskiwanie drewna
pozyskiwanie reczno-maszynowe
pilarki
ciagniki rolnicze
pozyskiwanie maszynowe
harwestery
uszkodzenia drzew
Źródło:
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej; 2014, 16, 2B[39]
1509-1414
Pojawia się w:
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Klasyfikacja ekotypowa samców sarny europejskiej (Capreolus capreolus L.) na podstawie wybranych pomiarów ich ciała
Ecotype classification of the European roe deer [Capreolus capreolus L.] males on the basis of selected body parameters
Autorzy:
Kulak, D.
Wajdzik, M.
Powiązania:
https://bibliotekanauki.pl/articles/1011776.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
samce
pomiary zoometryczne
zwierzeta lowne
lowiectwo
sarna polna
ekotypy
Capreolus capreolus
lesnictwo
kozly
sarna
sarna lesna
european roe deer
field ecotype
forest ecotype
regression model
neural network
Opis:
The studies were carried out on the European roe deer (Capreolus capreolus L.) males from field and forest ecotypes harvested in the Opole Region. Attempts were made to identify the ecotype of the examined individuals on the basis of skull and body measurements. It was found that the most useful measurements for ecotype identification are skull dimensions: LTO (profile length), LCB (condylobasal length), LBA (basal length), LV (length between the front edge of the occipital foramen and the end of the jawbone), LHM (mandible length) and MG (body weight). 82% of individuals were correctly classified using the regression analysis method, while the use of the neural network resulted in correctness ranging from 90 to 98% depending on the type of the network applied.
Źródło:
Sylwan; 2009, 153, 08; 563-574
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Charakterystyka uszkodzeń powierzchniowych warstw gleby podczas zrywki drewna ciągnikami rolniczymi w trzebieżowych drzewostanach sosnowych
Characteristics of topsoil layers damage during wood skidding with farm tractors in thinning pine-stands
Autorzy:
Sowa, J. M.
Kulak, D.
Powiązania:
https://bibliotekanauki.pl/articles/290341.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
trzebież
sosna
zrywka
ciągnik rolniczy
szkoda
gleba
thinning
pine
skidding
farm tractor
damage
soil
Opis:
Celem badań było określenie rozmiaru i poznanie cech charakterystycznych naruszeń pokrywy glebowej powstałych w trakcie wykonywania zrywki drewna za pomocą ciągników rolniczych. Zakres prac ograniczono do niżowych, trzebieżowych drzewostanów sosnowych. Zrywka drewna w trzebieżach wczesnych spowodowała zniszczenia pokrywy glebowej na 2,57% powierzchni zrębowej, a w późnych na 3,63% zrębu. Dominującą formą uszkodzeń były ubicia, których udział w trzebieżach wczesnych wyniósł 84%, zaś w późnych 67%. Z przeprowadzonych analiz wynika, że o zaobserwowanych w badaniach różnicach w poziomie szkód w wierzchniej warstwie gleby pomiędzy trzebieżami wczesnymi i późnymi zadecydowała liczba powstałych naruszeń gleby, a nie powierzchnia pojedynczych uszkodzeń.
The purpose of the research was to determine size and to get to know characteristic features of soil cover damage occurring during wood skidding with farm tractors. The scope of works was limited to lowland, thinning pine-stands. Wood skidding in first thinnings resulted in soil cover destruction at 2.57% of total felling area, and in secondary thinnings at 3.63% of total felling area. Compressions were prevailing form of damage. Their share in first thinnings reached 84%, and in secondary thinnings - 67%. Completed analyses indicate that differences in topsoil damage level between first and secondary thinnings, observed during the experiment, are determined by total number of soil damages, and not individual damage area.
Źródło:
Inżynieria Rolnicza; 2008, R. 12, nr 1(99), 1(99); 353-361
1429-7264
Pojawia się w:
Inżynieria Rolnicza
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Czasochłonność zrywki drewna skiderem z drzewostanu do szlaku operacyjnego
Time consumption of log extraction from the stand to the skid trail using the skidder
Autorzy:
Szewczyk, G.
Kulak, D.
Stańczykiewicz, A.
Powiązania:
https://bibliotekanauki.pl/articles/979045.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
timber harvesting
skidding
working time
time consumption
modelling
Opis:
Skidders are used at two stages of log extraction: when pulling logs to a skid trail and for further semi−suspended log skidding along the trail to a landing. The aim of the study is to characterise the working time structure of a skidder operator performing timber extraction from the stand to the trail, and to develop time−consumption models depending on terrain slope and skidding distance. The research was done in stands situated in central and southern Poland, where late thinning and cutting in areas between tree groups (group clear cut) were performed. The timber was transported to skid trails by means of LKT 82 cable skidders. The timber was pulled to the trail on slopes with inclinations ranging from –30° (up the slope) via 0° (on a flat surface) to 38° (down the slope) at a maximum distance of 70 m. Time study of work cycles was performed and the volume of timber harvested in each package was calculated. Analyses of working time and its time consumption were performed for the operational working time. The measurements covered a total of 269 log extraction cycles with a total duration of over 20 hours. Altogether 752 logs with a total volume of over 520 m3 were extracted. The large share of time was devoted to load attaching and detaching (40%). Quite a large share of log extraction (24%) was associated with the long skidding distances. The time of stretching the collecting rope in the case of skidding up the slope (an average of 60 s) was significantly shorter than in the flat terrain or skidding down the slope (70 s). The average duration of a skidding cycle was also affected by the direction of the slope. Rectilinear relationships were determined between the duration of a skidding cycle and the terrain slope, as well as the skidding distance. The combined effect of these features on the duration of skidding was described. The duration of a skidding cycle was influenced by distance (61% of the general variability) more than the slope (16%). The time consumption of the skidding amounted to ca 12 min/m3. Two homogeneous groups were determined: uphill skidding as well as skidding in flat terrain and downhill. The relationship between the time consumption and the number of logs extracted along with their volume took the form of an exponential regression. The time consumption standard of log extraction performed with the use of a skidder along a skid trail should be supplemented with the time of forming timber packages in the stand and pulling them to the trail, with an additional distinction between the direction of skidding and terrain slope.
Źródło:
Sylwan; 2020, 164, 04; 311-320
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ zrywki konnej na uszkodzenia wierzchnich warstw gleby w trzebieżowych drzewostanach sosnowych
The influence of horse skidding on upper soil layer disturbances in thinned pine stands
Autorzy:
Kulak, D.
Stanczykiewicz, A.
Szewczyk, G.
Powiązania:
https://bibliotekanauki.pl/articles/880553.pdf
Data publikacji:
2014
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Leśny Zakład Doświadczalny. Centrum Edukacji Przyrodniczo-Leśnej w Rogowie
Tematy:
lesnictwo
drzewostany sosnowe
pozyskiwanie drewna
zrywka drewna
zrywka konna
oddzialywanie na glebe
gleby lesne
warstwa wierzchnia
uszkodzenia gleby
Źródło:
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej; 2014, 16, 2B[39]
1509-1414
Pojawia się w:
Studia i Materiały Centrum Edukacji Przyrodniczo-Leśnej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wydajność zrywki drewna skiderem na terenach pochyłych
Efficiency of timber skidding on the slopes
Autorzy:
Kulak, D.
Stańczykiewicz, A.
Szewczyk, G.
Wala, L.
Powiązania:
https://bibliotekanauki.pl/articles/980264.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
pozyskiwanie drewna
zrywka drewna
skidery
struktura czasu pracy
wydajnosc pracy
modelowanie
timber harvesting
skidding
working time
modelling
Opis:
The aim of the study is to characterise the working time structure of an operator of the LKT 82 skidder performing timber skidding on the sloping area, and to develop models of efficiency and time−consumption of the work depending on selected factors characteristic of the described transport process. The research was performed in the Sucha Forest District (S Poland). We considered two treatments: late thinning and felling performed in stands with the dominating share of beech. Logs obtained with chainsaws were initially extracted with horses and laid at the slope road. Later on the additional skidding with skidder tractor was done. Continuous timing of individual operations was performed with the use of a microcomputer equipped with time measurement software (accuracy of 1 second). We also determined skidding distance using a GPS device, the number of extracted logs in the load, and the volume of the logs. The total timing measurements lasted for a total of 70 h 24 min 27 s. During that time, the tractor made 72 cycles, transporting 998 logs with a total volume of 493.3 m3. In the mature stand, the average skidding distance amounted to approximately 1,160 m, a single load consisted of 3−4 logs with a volume of 7.7 m3. The operational efficiency of the skidding was 9.1 m3/h. In the thinning stand, the skidding distance was 1,230 m, the average load consisted of 22 logs with a volume of 5.8 m3. The operational efficiency amounted to 7.8 m3/h, on average. The working time structure was dominated by auxiliary (over 60%) and effective (nearly 30%) times. The obtained regression models of the duration of activities from the group of operational times were characterised by high correlation coefficient (about 0.75 for skidding time and driving without a load). Relatively strong relationships (r > 0.5) were also found between the times of collecting cable pulling and load attachment, and the volume of the extracted loads, and in the case of the times of collecting cable pulling also the type of treatment performed. The regression models for the times of log stacking, pulling the loads up with the winch and detaching them, despite the fact that they were statistically significant, characterised by relatively low correlation coefficients. The relationship between skidding efficiency and skidding distance was also determined (fig.). The duration of skidding cycles was described using the multiple regression with the volume of single loads and the skidding distance as the determinants. The regression models of skidding efficiency and time−consumption of skidding cycles may find practical application in estimating the efficiency of the tasks performed in stands and under conditions similar to those analysed in the present research.
Źródło:
Sylwan; 2019, 163, 07; 601-609
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rozmiar i charakter naruszeń wierzchniej warstwy gleby powstałych podczas pozyskiwania i zrywki drewna w trzebieżach wczesnych drzewostanów świerkowych
The size and nature of damage to the topsoil caused by timber extraction and skidding during early thinning operations in spruce stands
Autorzy:
Sowa, J.
Kulak, D.
Stańczykiewicz, A.
Szewczyk, G.
Powiązania:
https://bibliotekanauki.pl/articles/973654.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
pozyskiwanie drewna
zrywka drewna
warstwa wierzchnia
uszkodzenia gleby
zrywka konna
zrywka linowa
wciagarka Multi-FKS
leśnictwo
lasy górskie
drzwostany świerkowe
trzebież wczesna
oddziaływanie na glebę
gleby leśne
timber harvest
damage
early thinning
horse skidding
winch skidding
Opis:
The study concerns the impact of two harvesting technologies – one based on a traditional horse skidding and one using a small MultiFKS winch powered by chainsaw motor on the size and nature of damage to the surface soil layer. The study was conducted in a spruce stand where early thinning was carried out. The total share of soil disturbed during harvesting operations was not large accounting for 2.99% of the cutting area for horse skidding and 1.73% for skidding using a MultiFKS winch. The volume of damage to the topsoil was 8.38 m3/ha and 2.64 m3/ha, respectively. The likelihood of disturbances of the soil layer was 47% for horse skidding and 31% for skidding by means of a winch. Both technologies were character−ized by a similar, ca 5% likelihood of cutting of topsoil to a depth larger than 5 cm. For both technologies the likelihood of soil compaction was significantly lower than soil cutting.
Źródło:
Sylwan; 2011, 155, 05; 330-339
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza struktury czasu pracy przy pielęgnacji upraw wykaszarkami spalinowymi
Analysis of shift time structure during tree culture cultivation with brush cutters
Autorzy:
Sowa, J.M.
Szewczyk, G.
Kulak, D.
Pasiowiec, W.
Powiązania:
https://bibliotekanauki.pl/articles/796537.pdf
Data publikacji:
2002
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Opis:
Together with the growth of young trees cultivation carried out by the National Forestry Board it became necessary to mechanize the works that would increase their efficiency with equally high quality. Recognition and optimalization of worktime structure of brush cutter operators during cultivation is of great practical importance in this context. Technological improvement of cultivation in the analysed experiment applied a square method (fig. 1), while technical rationalisation consisted in cutting around young trees. The worktime structure of the described workstand was defined with the help of a working day photography being taken for three days for four workers. Next the measured time data were classified according to a scheme from fig. l. A relatively high fraction of resting time and maintenance of the brush cutter in a workshift proved that an exploitation shift time coefficient of effectiveness was 0.61. On the basis of differences between effective worktime and rest distributions as well as technological stand-still and everyday maintenance it was presumed that the cause of frequent work breaks were repeated repairs of brush cutters.(fig. 6). High value of coefficient of operating time efficiency (0.93) proved the optimum choice of the applied technology. The work efficiency assumed for the experiment - three times higher than for a hand tool -indicates that it is necessary to turn to a hand-machine level of cultivating.
Wobec dużego rozmiaru prac pielęgnacyjnych realizowanych przez Lasy Państwowe niezbędna jest ich mechanizacja, podnosząca wydajność przy niezmienionej jakości wykonania. Poznanie i optymalizacja struktury czasu pracy operatorów wykaszarek spalinowych przy wykonywaniu pielęgnacji upraw ma w tym kontekście duże znaczenie praktyczne. Racjonalizacja technologii pielęgnacji upraw w analizowanym doświadczeniu polegała na stosowaniu metody kwadratu (rys. 1), zaś techniki pracy na obkaszaniu drzewek (rys. 2). Strukturę czasu pracy opisywanego stanowiska określono na podstawie fotografii dnia roboczego prowadzonej dla czterech robotników przez trzy dni. Następnie sklasyfikowano pomierzone czasy wg schematu z tab 1. Stosunkowo duży udział w zmianie roboczej czasów odpoczynków i napraw urządzenia tnącego (rys. 3) spowodował, że współczynnik wykorzystania eksploatacyjnego czasu zmiany wyniósł 0,61. Na podstawie różnic rozkładów efektywnego czasu pracy i odpoczynków oraz czasów przestojów technologicznych i codziennej obsługi maszyn wnioskowano, że przyczyną częstych przerw w pracy jest wielokrotna naprawa urządzenia tnącego (rys. 5). Zależność tą potwierdzono, charakteryzując istniejący związek jako zależność liniową (rys. 6). Wysoka wartość współczynnika wykorzystania czasu operacyjnego - 0,93 - potwierdziła optymalny dobór zastosowanej technologii prac. Określona w doświadczeniu wydajność prac - trzykrotnie wyższa w porównaniu z narzędziem ręcznym, wskazuje na konieczność przejścia na poziom ręczno-maszynowy wykonywania pielęgnacji upraw.
Źródło:
Zeszyty Problemowe Postępów Nauk Rolniczych; 2002, 486, 1
0084-5477
Pojawia się w:
Zeszyty Problemowe Postępów Nauk Rolniczych
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Czynniki wpływające na zmiany zwięzłości gleb leśnych podczas pozyskiwania surowca drzewnego
Factors affecting the changes in penetration resistance of forest soils during timber harvesting
Autorzy:
Kulak, D.
Stańczykiewicz, A.
Szewczyk, G.
Lubera, A.
Strojny, T.
Powiązania:
https://bibliotekanauki.pl/articles/989881.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
drzewostany sosnowe
trzebiez pozna
pozyskiwanie drewna
metody pozyskiwania drewna
oddzialywanie na glebe
gleby lesne
ugniatanie gleby
zwiezlosc gleb
timber harvesting
mechanized
motor−manual
soil penetration resistance
Opis:
The objective of the studies was to determine the penetration resistance (cohesion) of soil compacted at timber harvesting in Scots pine stands subjected to late thinning. The scope of the investigations was limited to two technologies – the mechanized one, using a harvester−forwarder machine set, as well as the motor−manual one, employing petrol chainsaws and a farm tractor for forwarding and dragging of felled trees. The analyses were performed in central Poland, in the Staszów Forest District, for two habitats – fresh mixed coniferous forest and fresh mixed deciduous forest. The measurements of soil cohesion were taken with the use of Eijkelkamp 06.15.SA Penetrologger penetrometer along the five measurement lines situated perpendicularly to the main skidding track. The soil penetration resistance was measured in eight spots for every measurement line: in the middle of the left and right wheel−rut, between the wheel−ruts, on the left and right roadside within a distance of 0.5 and 1 m from the wheel−rut edge, and 10 m from the right wheel−rut; the latter location was treated as the reference. The mechanized timber harvesting caused stronger compaction of soil, particularly in wheel−ruts, where the recorded values of soil cohesion exceeded 3 MPa (fig. 1). For the technology with farm tractor for skidding, the greatest soil compaction was also encountered in wheel−ruts, reaching up to 2.5 MPa. With regard to both logging technologies, the analysis of variability in penetration resistance of the top 10−cm soil horizon revealed a statistically significant increase in soil compaction in wheel−ruts when compared with other measuring points along and nearby the skid track (fig. 2). The employed technology of timber harvesting and the degree of soil cohesion in wheel−ruts were proved to be correlated. In respect of the mechanized variant, the mean value of soil penetration resistance in the top 10−cm layer counted up to 2 MPa and was significantly greater than the one in motor−manual technology, where it did not exceed 1.3 MPa. No significant differences in soil compaction in reference to the investigated forest habitats were revealed, though it was stronger in fresh mixed coniferous forest, with regard to both technological variants. The motor−manual technology caused the increase in soil penetration resistance by 2% on the roadside, nearly 20% in the middle of the skid track and over 70% in wheel−ruts. While the mechanized logging operations resulted in 30% increase in soil cohesion on the roadside, 55% between the wheel−ruts and over 250% inside the wheel−ruts (fig. 3).
Źródło:
Sylwan; 2015, 159, 04; 318-325
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nomenclatural changes in Liparis-complex [Malaxidinae, Epidendroideae]
Autorzy:
Szlachetko, D L
Margonska, H.B.
Kulak, M.
Powiązania:
https://bibliotekanauki.pl/articles/59241.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
taxonomy
Disticholiparis
Australasia
Epidendroideae
Cestichis
Liparis
Malaxidinae
nomenclatural change
Opis:
Explanation of taxonomic and nomenclatural problems of few taxa of Liparis sensu lato are compiled. Taxonomic status of Disticholiparis is confirmed. New nomenclatural combinations within Stichorkis are proposed.
Źródło:
Acta Societatis Botanicorum Poloniae; 2008, 77, 1
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The physical and occupational activity of patients with multiple sclerosis depending on the form of clinical disease
Autorzy:
Wyszyńska, E.
Sienkiewicz, D.
Kułak, W.
Powiązania:
https://bibliotekanauki.pl/articles/1918844.pdf
Data publikacji:
2019-08-26
Wydawca:
Uniwersytet Medyczny w Białymstoku
Tematy:
Multiple sclerosis
physical activity
occupational activity
Opis:
Introduction: The progressive nature of multiple sclerosis (MS) is associated with numerous neurological deficits, leading gradually to deteriorating health and to disability. Purpose: The aim of this study was a subjective assessment of the physical and occupational activity of individuals with MS depending on the clinical form of the disease. Materials and methods: We used the original to conduct the research, with 28 closed questions. The study was carried out from December 1, 2018, to January 31, 2019, following approval by the Bioethics Committee of the Medical University of Bialystok, among persons belonging to the Association for Helping Sick People for Multiple Sclerosis in Białystok and patients of the Neurology Department of the University Clinical Hospital in Bialystok. The study sample comprised 50 people diagnosed with MS, 41 women and 9 men. Results: The most frequently occurring clinical form of MS was relapsing-remitting (68%). In this form, most participants had good physical fitness (44%). In those with the progressive-recurrent form (50%), very poor physical fitness was subjectively noted. Of those with the relapsing-remitting type of MS, 50% were professionally active, while none of the participants with the progressive-recurrent form were. Both the physical and occupational activities of MS patients were frequently limited by fatigue, balance disturbances, and movement difficulties. Fatigue was the most common symptom for most individuals with MS (82%). Conclusion: MS has a significant impact on both the physical activity and occupational functioning of patients. In the clinical form of MS, relapsing-remitting, patients’ physical fitness was better.
Źródło:
Progress in Health Sciences; 2019, 1; 126-131
2083-1617
Pojawia się w:
Progress in Health Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
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