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Tytuł:
Analiza i ocena wyników gospodarowania w Lasach Państwowych w minionym dwudziestoleciu
Analysis and evaluation of forest management in the State Forests National Forest Holding in the last two decades
Autorzy:
Poznański, R.
Powiązania:
https://bibliotekanauki.pl/articles/972780.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
Polska
Panstwowe Gospodarstwo Lesne Lasy Panstwowe
gospodarka lesna
gospodarka zrownowazona
pozyskiwanie drewna
wyniki gospodarowania
ocena wynikow
average age
average standing volume
volume increment
final cut
intermediate cut
planned
and executed cut
Opis:
Forest management in the State Forests in the past two decades (1990−2009) focused solely on the aging of forest stands and augmentation of forest resources. This period saw an increase in the average age of forest stands from 54 to 61 years, the average standing volume from 186 to 245 m3/ha, and the share of harvested volume in annual increment volume from 50 to 58%. As a result, the share of stands older than 80 years increased from 21 to 28% while that of plantations and young stands decreased from 14.4 to 11%. This resulted in the deterioration of the health and sanitary condition of forests.
Źródło:
Sylwan; 2012, 156, 07; 542-547
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ocena szkód w lasach Polski spowodowanych przez huragan w sierpniu 2017 roku
Assessment of the damage to Polish forests caused by a hurricane in August 2017
Autorzy:
Dmyterko, E.
Bruchwald, A.
Powiązania:
https://bibliotekanauki.pl/articles/978974.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
wind−caused damage
risk model
stand growth model
allowable cut
Opis:
On August 11−12, 2017, a hurricane passed from south to north of Poland causing considerable damage to forests, especially in regional directorates of the State Forests in Wrocław, Poznań, Toruń, Szczecinek and Gdańsk. By the end of 2018, the volume of wind−broken and wind−fallen trees and deadwood approximated to 9 million m3. In 9 forest districts the harvested volume exceeded 440 thousand m3, including two entities with over 1 million m3 each. The harvested volume was expressed as a percentage of allowable cut, calculated from the stand growth model. It showed possibile timber harvest in final and intermediate cuts in the absence of natural disasters (strong wind, intense drought, heavy snowfall, insect outbreaks, etc.). In many forest districts, timber harvest accounted for 100% of the allowable cut, with the maximum value approximated to 1100% of the allowable cut. The high salvage harvest of post−hurricane timber prevents the execution of other economic tasks, including plans of stand rebuilding. On the example of forest districts with the largest damage, the possibilities of selecting forests classified as the most threatened by wind were examined. The wind damage risk model for the stand was used to determine the value of wind damage risk factor Wr for each stand (values from 0 to 3; the higher value, the higher risk). The damage risk factor allowed to create six damage risk classes of a span of 0.5 each and to assign individual stands to one of the damage classes. The share of the area of stands and damaged stands in Wr classes was also determined. In the Lipusz Forest District the share of stands in VI class of Wr was 9.8%, and the area of damaged stands in this class was 98.3%. In the Rytel and Przymuszewo forest districts, the areal share of such stands was 10.7% and 5.1%, respectively, and almost all stands in this class were damaged by the hurricane. The areal share of forests in the highest Wr class was reported in the Gniezno Forest District accounting for 4.8% and the hurricane damaged 85% of their area. The wind damage risk model for the stand allows to identify forests where damage is very likely to occur. It is, therefore, possible to take action on the rebuilding of stands before the wind comes and thus reduce its negative effects. The cutting plan should include, in the first place, stands classified to the high wind damage risk factor.
Źródło:
Sylwan; 2020, 164, 05; 355-364
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Warunki wilgotnościowe powietrza na zrębie zupełnym i gnieździe
Air humidity on the clear-cut and the gap
Autorzy:
Chojnacka-Ożga, L.
Ożga, W.
Andrzejczyk, T.
Powiązania:
https://bibliotekanauki.pl/articles/979332.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
clear−cut
gap
vapour pressure
relative humidity
vapour pressure deficit
Opis:
The aim of the study was to determine the spatial variation of vapour pressure (e), relative humidity (f) and vapour pressure deficit (Δ) on the clear−cut and gap as well as to compare the spatial distribution of air humidity conditions on both areas. The research was carried out in Rogów Forest Experimental Station (51.827023°N, 19.922315°E) on a clear−cut with a width of 60 m and on a gap of an ellipsoid shape (40×70 m). The measurements were carried out in two series: spring−summer, i.e. in the period when the height of the sun during the day conditioned inflow of direct solar radiation to any surface (May−August 2006), and autumn, i.e. when direct radiation was limited by neighbouring stands (October−November 2006). We found the modest spatial diversification of vapour pressure that, on average, amounted to 0.4 and 0.2 hPa in the clear−cut and gap, respectively, in spring−summer period as well as 0.3 and 0.7 hPa, respectively, in the autumn. The major impact of the clear−cut and gap location was marked in relative humidity and humidity deficit. Differences in relative humidity on the clear−cut amounted averagely to 3.7 and on the gap 12.7%, whereas the humidity deficit equalled 0.3 and 5.4 hPa, respectively. Particularly large diversification of relativity humidity and vapour pressure deficit was in spring−summer period in the situation of heat waves. In that weather conditions in sun−filled clear−cut and gap parts, the relativity humidity fall to about 17%, whereas vapour pressure deficit increased to about 60 hPa. In the same clear−cut and gap parts the occurrence of dry days was more frequent that in other places. It was noticed that in the positions located in sun−filled clear−cut and gap parts (z4, g3), the diurnal vapour pressure course was very similar to the one observed in the forest, whereas the course of the relativity humidity and vapour pressure deficit was significantly different. That is mainly involved with the extreme thermal conditions in this parts of the studied areas. The least beneficial humidity conditions for plants growth occurred in the north−east parts of clear−cut and gap, that’s why it necessary to take particular note of these locations when undertaking the silvicultural treatments.
Źródło:
Sylwan; 2020, 164, 07; 594-603
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prognoza użytkowania Lasów Państwowych na okres 2011-2020
Forecast of the harvest in the State Forests for the 2011-2020 period
Autorzy:
Poznański, R.
Powiązania:
https://bibliotekanauki.pl/articles/973942.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
zasoby drzewne
prognozy gospodarcze
użytkowanie przedrębne
leśnictwo
użytkowanie rębne
gospodarka leśna
Państwowe Gospodarstwo Leśne Lasy Państwowe
the state forests
stand survival and harvest probability
inductive forecast
final cut
intermediate cut
Opis:
Final and intermediate cuts volume in the State Forests are expected to range in 2011−2020 from 18.28 to 23.90 and from 13.39 to 13.58 million m3 netto annually respectively, with probability of 0.954. The final cut will account for about 60% of the principal harvest. Positive changes will occur during the forecast period in the average stand age from 3 to 4 years and in the average standing volume from 3 to 5 m3/ha.
Źródło:
Sylwan; 2011, 155, 12; 827-834
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mikoryza siewek i sadzonek drzew leśnych w odnowieniach na powierzchniach zrębowych
Mycorrhiza of forest tree seedlings in clear-cut regenerations
Autorzy:
Aleksandrowicz-Trzcińska, M.
Powiązania:
https://bibliotekanauki.pl/articles/1016143.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
grzyby mikoryzowe
zreby
sadzonki
mikoryza
lesnictwo
siewki
drzewa lesne
ectomycorrhizal fungi
regeneration
clear−cut
Opis:
Biotic and abiotic factors affecting the development of ectomycorrhizal fungal communities in forest regenerations on clear−cuts were discussed basing on the relevant literature.
Źródło:
Sylwan; 2007, 151, 11; 3-9
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biegaczowate (Col. Carabidae) na zrębach w Puszczy Białowieskiej
Ground beetles [Col. Carabidae] in cutting areas in the Bialowieza Primeval Forest
Autorzy:
Skłodowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1018610.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
owady
zreby
entomologia lesna
lesnictwo
biegaczowate
Puszcza Bialowieska
Carabidae
primeval forest
cler−cut area
carabidae
białowieża
Opis:
The research on ground beetle assemblages was carried out in the virgin forests of the Białowieża Primeval Forest and in managed forests. Ground beetle assemblages in restocked cutting areas were characterized by lower values of the indicators characterizing the state of their successional development: MIB and SCP, participation of relict and wingless species. No differences in the number of species harvested in virgin forests and regenerated stands were confirmed.
Źródło:
Sylwan; 2006, 150, 10; 3-11
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kolej rębu drzewostanów sosnowych według kryteriów ekonomicznych
Rotation age of pine stands on the basis of economic criteria
Autorzy:
Bednarski, K.
Miscicki, S.
Powiązania:
https://bibliotekanauki.pl/articles/972950.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
pozyskiwanie drewna
drzewostany sosnowe
kryteria ekonomiczne
leśnictwo
gospodarstwa zrębowe
kolej rębu
final cut
forest habitat type
income
maturity
value
Opis:
There is a lack of an acceptable and practical method for calculating the optimal moment at which a forest stand is considered ready for felling. The aim of the research was to: (1) develop a concept for the calculation of the rotation age for forest stands based on economic criteria and (2) develop a methodology for obtaining and processing empirical data necessary for such calculation. It is assumed that stands are felled at the age affecting the age structure (area of age classes) of a forest in such a way that the difference between revenues from the sale of timber harvested in inter−mediate cuts and final cuts and the costs of timber harvest, silvicultural management, forest protection and administration is the largest. The developed method of calculating the rotation age was tested on the example of three Scots pine forests under the clear−cutting system representing typical forest habitats. The collected empirical material consisted of (1) own measurement data used to determine the value of the growing stock, and (2) data from the State Forests Information System used to determine the management costs, timber prices and the volume of timber harvested from intermediate cuts. These data helped to calculate the relationship between the income from a forest (including: revenues from the final and intermediate cuts, costs of forest management as well as timber harvesting and extraction) and the rotation age. The highest net income was when the rotation age was 108−125 years. The more fertile habitat, the shorter was the rotation age. The proposed methodology can be treated as a useful tool for the calculation of rotation age related to forest management in Poland. The dependence of income from a forest on the rotation age can be used to calculate losses that may arise when other than an optimal rotation age is applied.
Źródło:
Sylwan; 2016, 160, 03; 197-206
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ocena metod i zasad gospodarowania w Lasach Państwowych w minionym dwudziestoleciu
Evaluation of the methods and principles of forest management in the State Forests in the past two decades
Autorzy:
Poznański, R.
Powiązania:
https://bibliotekanauki.pl/articles/991592.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
Panstwowe Gospodarstwo Lesne Lasy Panstwowe
gospodarka lesna
gospodarka zrownowazona
lasy gospodarcze
lasy ochronne
uzytkowanie rebne
uzytkowanie przedrebne
wiek rebnosci
regulacja uzytkowania rebnego
rotation age
allowable cut
cut determination by silvicultural needs
forest management planning
location of cutting sites
ecological forest management
Opis:
The adopted rotation age and prescribed cut are found not to be fully respected at any stage of regulation, planning and implementation of cutting plans. As a result, timber, the main crop in forestry, is not uniform in terms of rotation age and fails the adopted criteria of crop maturity. Protective forests are not subject to management unless cut determination derives from silvicultural needs, without specifying the criteria for these needs. The level of cuts subjectively determined by quality control inspectors is not respected in forest management practice and should be recommended for use in the forests administered by the State Forests.
Źródło:
Sylwan; 2013, 157, 04; 298-305
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Aspekty prawne określania wielkości użytkowania przedrębnego
Legal aspects of determining intermediate cut
Autorzy:
Borecki, T.
Pieniak, D.
Wójcik, R.
Powiązania:
https://bibliotekanauki.pl/articles/973975.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
aspekty prawne
regulacja uzytkowania przedrebnego
leśnictwo
użytkowanie lasu
użytkowanie przedrębne
regulacja użytkowania przedrębnego
forest management planning
forest utilisation regulation
intermediate cut
Opis:
The article depicts the legal aspects of determining intermediate cut in the State Forests. Analysed methods show a gradual departure from the stand−level management planning to that based on unit larger than a stand in the subsequent versions of the amended forest management planning instruction.
Źródło:
Sylwan; 2011, 155, 02; 75-83
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Regulacja warunków wzrostu odnowień na gniazdach - wpływ parametrów gniazd na oddziaływanie czynników biotycznych
Regulation of regeneration growth conditions in small clear cuts - the effect of gap parameters on biotic factors influence
Autorzy:
Bolibok, L.
Powiązania:
https://bibliotekanauki.pl/articles/1009593.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
czynniki biotyczne
odnowienia lasu
rosliny konkurencyjne
luki korzeniowe
lasy
lesnictwo
rebnie gniazdowe
dostepnosc skladnikow pokarmowych
small clear cut
patch selective cutting
gaps
root gaps
weeds
optimization
Opis:
Optimisation of patch selective cutting, especially the interaction between size and shape of artificial gaps and biotic factors influencing tree regeneration, is rather sparsely documented in Polish silvicultural textbooks. The removal of trees can increase availability of nutrients in artificial gaps. Establishment of root gaps and vigorous development of vegetative cover (weeds) is another consequence. This paper presents review of investigations that describe interactions between mentioned factors influencing regeneration growth and parameters of gaps. The special attention is paid to potential application of cited results in practical silviculture.
Źródło:
Sylwan; 2009, 153, 11; 733-744
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Urządzanie lasu wobec wyzwań wielofunkcyjnego gospodarstwa leśnego
Forest management planning in the face of challenges for a multifunctional forest holding
Autorzy:
Poznański, R.
Powiązania:
https://bibliotekanauki.pl/articles/973154.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
las wielofunkcyjny
urządzanie lasu
leśnictwo
gospodarka leśna
multifunctional forest
forest of exceptional values and functions
management system
prescribed cut
based on silvicultural needs
forest regulation method
Opis:
In this paper it has been established that multifunctional forests in Poland are not subject to regulation. It has been proposed that all multifunctional forests be divided into two categories: I – forests with exceptional (extraordinary) values and functions and II – other multifunctional forests.
Źródło:
Sylwan; 2007, 151, 03; 23-28
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zgrupowania biegaczowatych jako zooindykatory różnych sposobów przygotowania gleby na zrębach oraz ich zagospodarowania
Carabid communities as zooindicators of soil scarification techniques applied in clear-cutted forest stands and the further used management practices
Autorzy:
Skłodowski, J.
Powiązania:
https://bibliotekanauki.pl/articles/1009276.pdf
Data publikacji:
2010
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
zreby
zrab zupelny
zagospodarowanie lasu
gleby lesne
przygotowanie gleby
bioindykacja
bioindykatory
owady
biegaczowate
Carabidae
zgrupowania zwierzat
clear cut area
soil preparation
carabidae
structure of assemblages
regeneration
Opis:
In this paper the effect of different methods of soil scarification in a clear−cut area were studied. The following soil preparation techniques were applied: the soil cutter, the active soil plough, the traditional method with use of LPz plough, and the manual scarification of soil in circles surrounding the stem of the future young tree. The effect of management of the residual heaps of branches was also tested. Branches were either put in prisms in the original shape or, having been previously chipped, equally distributed over the entire area of the clear−cut. Additional studies focused on the effect of the time of clear−cut execution (winter or summer) on the condition of epigeic carabid communities. The least regressive effect to analysed communities was observed after the application of the point manual soil scarification. The clear−cuts carried out during the winter season, to a greater degree, favours the forest carabid fauna, preserving them in a structure more resembling the forest communities. More distinctive positive effect on the carabids is observed after putting the residual heaps of branches in prisms; the latter gives shelter for the carabid fauna and constitutes the refuge spots for it.
Źródło:
Sylwan; 2010, 154, 09; 625-638
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ sposobu przygotowania gleby na cechy odnowienia naturalnego sosny zwyczajnej (Pinus sylvestris L.) w Nadleśnictwie Spychowo
Effect of mechanical site preparation methods on characteristics of the natural regeneration of Scots pine (Pinus sylvestris L.) in Spychowo Forest District
Autorzy:
Aleksandrowicz-Trzcińska, M.
Drozdowski, S.
Ligocki, M.
Żybura, H.
Powiązania:
https://bibliotekanauki.pl/articles/987039.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
hodowla lasu
Nadlesnictwo Spychowo
odnowienia naturalne
przygotowanie gleby
sosna zwyczajna
Pinus sylvestris
siewki
zageszczenie roslin
przezywalnosc
wzrost roslin
soil scarification
self−sowing
seedling density
seedling growth
clear−cut
Opis:
Mechanical site preparation is recommended to create optimum conditions for seed germination and seedling growth in a clear−cut area. Lack of soil scarification or less−intense methods may be more suitable from an environmental point of view, but can result in a failure to obtain natural regeneration. This study compared the effects of three mechanical site preparation methods (SPM) characterized by different levels of soil scarification (i.e. double mould−board forest plough (LPz), active plough (PA) or forest mill (FL)), as well as a control variant without mechanical site preparation, on height, density, spatial distribution and survival among naturally regenerating Scots pines (Pinus sylvestris L.) in the first 2 years of growth in a clear−cut area of NE Poland. The experiment was based around a four−block randomized block design involving the four variants. Seedling height was measured at the end of the first and second growing seasons, with measurements performed on 8 meter−wide transects extending across the entire width of the cleat−cut. We found no effect of SPM on seedling height, though the density of seedlings regenerating naturally was found to be dependent. After two years, the highest density was achieved in the PA variant (8.1 seedlings/m2) and the FL variant (7.0 seedlings/m2). A significantly lower density characterized the LPz variant (5.1 seedlings/m2) and the lowest of all the variant without soil scarification (3.2 seedlings/m2). The most homogeneous natural regeneration was achieved following the use of PA (2.6% of 1 m2 plots without seedlings after two growing seasons), while the least homogeneous was the variant without soil scarification (22.4% of 1 m2 plots). Survival of pines after the second growing seasons was quite high (over 80%), and did not differ significantly depending on the SPM. Our research therefore confirmed that, in the absence of mechanical site preparation, natural regeneration of sufficient density and homogeneity cannot be obtained. The best natural regeneration was obtained on sites prepared with PA, and FL scarification being only slightly less favorable. The low density and uneven distribution of seedlings on the soil prepared with LPz was a surprising result. The probable reason for this lay in the high precipitation in the first growing season. On one hand, this provided very good moisture conditions for seed germination and seedling growth on a substrate with high porosity in the PA and FL variants, but on the other the high bulk density of mineral soil in the LPz variant led to oxygen deficit.
Źródło:
Sylwan; 2017, 161, 03; 196-207
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wpływ mechanicznego przygotowania gleby na zrębie na jej cechy
Effect of mechanical site preparation on features of the soil in a clear-cut area
Autorzy:
Aleksandrowicz-Trzcińska, M.
Drozdowski, S.
Żybura, H.
Powiązania:
https://bibliotekanauki.pl/articles/986611.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
zreby
przygotowanie gleby
zabiegi mechaniczne
maszyny lesne
plug LPZ
plug aktywny jednotalerzowy
frez lesny
gleby lesne
wlasciwosci fizyczne
wlasciwosci chemiczne
forest plough
active plough
forest mill
soil scarification
clear−cut
Opis:
In most cases, mechanical site preparation (MSP) is a precondition if high−quality (natural or artificial) regeneration of forests is to be achieved. However, the measures involved here may differ in terms of the level of intervention of the soil environment, at both the surface and deeper down. The choice of MSP methods should be based on climatic conditions, site type and the species whose renewal is sought, while the effect should improve conditions for the emergence and growth of the young generation of trees, with the influence on the soil environment being limited as far as possible. The research sought to compare physical and chemical features of the soils of the microhabitats created in clear−cut areas as a result of MSP using either an LPz double mould−board forest plough (furrow and ridge), an active plough (furrow and ridge) and a forest mill (belt and beyond the belt) as compared with unscarified soil. Investigated physical features included grain size (content of sand, silt and clay), bulk density and actual moisture, while the chemical ones: pHH2O and pHKCl, exchangeable acidity, total content of N and C and the C/N ratio, P2O5 content and base cations Mg2+, Ca2+, K+ and Na+. The most invasive MSP method for the soil environment is the active plough, which leaves the ridge exposed to processes of the decomposition of organic matter (and the highest content of N, C, Mg2+, Ca2+ and K+). Equally, this method may pose the greatest threat of mineral components of the soil being leached, with impoverishment of the habitat ensuing. The forest mill in turn offers the least invasive MSP. Most of the physical and chemical features of soil (other than exchangeable acidity and pHH2O and pHKCl) both in the belt areas and beyond them differed little from the those characterising non−scarified soil. Also the analysed features determined for the furrows ploughed by the active or LPz ploughs or the belt prepared using the forest mill did not differ significantly.
Źródło:
Sylwan; 2018, 162, 08; 648-657
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Utrata masy i zmiany gęstości średniowymiarowego surowca sosnowego pozyskanego i magazynowanego w okresie letnim
Weight loss and green density changes of Scots pine pulpwood harvested and stored during the summer
Autorzy:
Tomczak, A.
Wesołowski, P.
Jelonek, T.
Jakubowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/989611.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Leśne
Tematy:
lesnictwo
pozyskiwanie drewna
lato
sosna zwyczajna
Pinus sylvestris
drewno sosnowe
drewno sredniowymiarowe
drewno swiezo sciete
magazynowanie
utrata masy drewna
gestosc drewna
scots pine
mass of logs
timber
freshly−cut trees
bark
wood moisture
Opis:
The study objectives included: i) determination of the mass and green density of pulpwood (wood+bark) and ii) comparison of the changes in these parameters during 14−day−long storage period. The experiment was conducted between 15 and 28 July 2014 and the material was taken from the 67 year−old Scots pine stand (Tuchola Forest District, northern Poland). Using the Urich method, 30 model trees were selected. After felling and delimbing, logs of 2.5 m length were cut, with diameter at the small end not less than 7 cm outside the bark. In total, 133 logs were harvested (mean diameter inside the bark at the thicker end – 13.1 cm, in the thinner end – 11.4 cm). After diameter measurements were taken, each log was weighed (total over bark volume equaled 4.69 m³, while total weight – 3955 kg). Mass measurement took place daily between 8 and 10 a.m. In Poland, the raw material is not recommended to be stored too long in summer, due to the possibility of its depreciation. Storage time should be as short as possible and not exceed 2 weeks. The mass of the 1 m³ of wood harvested from freshly−cut trees amounted to 844 kg. After 14 days it decreased to 814 kg (–3.5%). Differences were not statistically significant. Because the moisture content has the highest influence on mass, the rain and thereby an increase in the air humidity significantly reduce drying. Mass of 1 m³ of raw material was reduced to the day of rain by 2.9 kg (–0.35%) per day on average. After the occurrence of rainfall, between 10th and 14th day of storage the mean weight loss was 1.3 kg/m³ (–0.16%). The mean weight loss reached 30 kg/m³ in analyzed period. Generally two weeks storage is too short time to obtain a large weight loss. However, in this case of total mass of haulage vehicles together with their cargo may be a few hundred kilos smaller.
Źródło:
Sylwan; 2016, 160, 08; 619-626
0039-7660
Pojawia się w:
Sylwan
Dostawca treści:
Biblioteka Nauki
Artykuł

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