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Wyszukujesz frazę "young stands" wg kryterium: Wszystkie pola


Wyświetlanie 1-9 z 9
Tytuł:
Physiological workload of workers employed during motor-manual timber harvesting in young alder stands in different seasons
Autorzy:
Grzywiński, Witold
Turowski, Rafał
Jelonek, Tomasz
Tomczak, Arkadiusz
Powiązania:
https://bibliotekanauki.pl/articles/2085735.pdf
Data publikacji:
2022-08-01
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
forestry
heart rate
energy expenditure
logging
winter
summer
Opis:
ObjectivesThis study examined the physiological strain experienced by workers employed in motor-manual timber harvesting performed in winter and summer, and the applicability of heart rate indices for estimating energy expenditure.Material and MethodsThe heart rates (HR) of 2 teams consisting of 2 persons working simultaneously during felling and forwarding, in both winter and summer, were measured. Heart rate at work (HRwork), resting heart rate (HRrest), relative heart rate (%HRR), ratio of working heart rate to resting heart rate, and 50% level were used to estimate the physiological workload in particular jobs. The HRindex (HRwork/HRrest) equation was used to estimate the energy expenditure (EE). ResultsFor all jobs, significantly higher physiological workload and energy expenditure were recorded during winter.ConclusionsThe season significantly affects the physiological workload during logging operations. If there is no possibility of harvesting wood in summer, in order to limit the workload of workers during winter activity, attention should be paid to the proper organization of work and selection of workers.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2022, 35, 4; 437-447
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Above- and below-ground tree parameters and their development after modelling of thinning in young elm stands
Autorzy:
Šrámek, Martin
Hurt, Václav
Čermák, Jan
Powiązania:
https://bibliotekanauki.pl/articles/956995.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
elm
leaf area
absorptive root area
biomass
thinning
Opis:
During the last century almost two-thirds of all elms were lost due to the Dutch elm disease. Therefore, elms are an endangered species with a lasting lack of knowledge about ecosystem functions of elms in forest stands. The study describes several above- and below-ground tree parameters and their changes after simulation of thinning in one young forest stand with dominant Ulmus laevis Pall. in the Czech Republic. The distribution of the leaves was measured using the ‘cloud’ technique. The absorptive root area was measured with the aid of the modified earth impedance method to evaluate below-ground tree parameters. Using allometric equations, it was possible to calculate certain tree parameters of individual trees as well as the entire forest stand. The modelling of four thinning intensities (low, medium, high and very high) helped to establish the changes of these tree parameters after treatment. The leaf area index of the stand was 5.6, the absorptive root area index was 1.7 and the total biomass of foliage was 8.5 Mg ha–1 prior to the treatment. The absorptive root area amounted to 30% of the foliage area. The exponential models were developed to predict the above- and below-ground tree parameters. Under the different thinning intensities, the following were found: a negative correlation with the number of trees for the leaf area index, the foliage biomass and the absorptive root area index. This knowledge is important in the process of maintaining the presence of endangered elms in forest stands and in ecosystem services (e.g. carbon storage) throughout Europe.
Źródło:
Dendrobiology; 2017, 77; 77-90
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Age-related changes in leaf area index of young Scots pine stands
Autorzy:
Jagodzinski, A M
Kalucka, I.
Powiązania:
https://bibliotekanauki.pl/articles/41483.pdf
Data publikacji:
2008
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
Scotch pine
Pinus sylvestris
leaf area index
age-related change
young tree
pine stand
allometric equation
chronosequence
Opis:
We studied the chronosequence of six Scots pine (Pinus sylvestris L.) plantations (6-, 9-, 11-, 15-, 17-, and 20-years-old) to examine the changes in leaf area index (LAI) over stand age. The study site was located on a mine spoil heap (outer dumping ground) in the Belchatow lignite open-cast mining district (central Poland). The main goal of the study was to analyze LAI changes over stand age in a chronosequence of young Scots pine stands and to test the relationship between LAI estimates derived from a LAI-2000 Plant Canopy Analyzer and site-specific allometric equations. In addition, we tried to determine whether LAI estimated by a LAI-2000 PCA can be used to accurately estimate forest biomass. We hypothesized that LAI-2000 PCA underestimates LAI of the stands, and that stand age (and linked stand parameters) may influence the range of the hypothetical underestimation due to changes in biomass allocation. Our study revealed that LAI was highly dependent upon stand age and tree density (p<0.0001) regardless of the way how LAI was determined. Moreover, we found that LAI estimated by LAI-2000 PCA significantly correlates with stand biomass per area; the highest coefficients of determination were found for total aboveground biomass, aboveground woody biomass, and stem biomass. This means that data obtained by LAI-2000 PCA are good predictors of stand biomass in the young stages of stand development. In contrast to our prior assumption, the results showed that LAI-2000 PCA overestimates leaf area index. The relative differences between the values obtained with LAI-2000 and those calculated on the basis of the site-specific allometric equations increase with age. This may reflect changes in crown architecture over age caused by enlarging tree dimensions and over - crowding of trees leading to deterioration of light conditions inside the canopy.
Źródło:
Dendrobiology; 2008, 59; 57-65
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biomass dynamics in young silver birch stands on post-agricultural lands in Central Poland
Autorzy:
Zasada, M.
Bijak, S.
Bronisz, K.
Bronisz, A.
Gaweda, T.
Powiązania:
https://bibliotekanauki.pl/articles/52729.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Drewna
Tematy:
biomass dynamics
young tree
silver birch
stand
secondary succession
afforestation
biomass allocation
post-agricultural land
Central Poland
Opis:
The paper analyses the production and allocation of biomass in young, spontaneoussilver birch afforestation occurring on post-agricultural lands in the Mazowszeregion (central Poland). We investigated 114 sample plots of age varying from 1 to 19 years. During the first 15 years after their establishment on abandoned farmland, the naturally regenerated silver birch stands produced on average approximately 75 tons of dry biomass per hectare. The major (50–70%) part of this biomass was stored in the tree stems and this share increased with age. The fractions of biomass in the foliage and roots decreased over time, while the share of biomass in the branches remained rather constant. The significant age-dependency of the allometric relationships suggested the need to use age-sensitive biomass expansion factors to estimate the biomass from the stem volume.
Źródło:
Drewno. Prace Naukowe. Doniesienia. Komunikaty; 2014, 57, 192
1644-3985
Pojawia się w:
Drewno. Prace Naukowe. Doniesienia. Komunikaty
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Aboveground biomass allocation and accumulation in a chronosequence of young Pinus sylvestris stands growing on a lignite mine spoil heap
Autorzy:
Jagodzinski, A.M.
Kalucka, I.
Horodecki, P.
Oleksyn, J.
Powiązania:
https://bibliotekanauki.pl/articles/41764.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
aboveground biomass
allocation
accumulation
chronosequence
age
young plant
Pinus sylvestris
stand
lignite mine
spoil heap
Opis:
It is not clear to what extent trees growing on anthropogenic sites change their growth and biomass allocation to different organs. We assessed the aboveground biomass in a chronosequence of six Scots pine monocultures (between 6 and 20 years old) to examine how precisely the site-specific or control allometric equations may reflect the value of biomass accumulation and allocation in stands growing in harsh site conditions on the overlayer spoil heap made as a result of opencast brown coal mining. The site is characterized by poor edaphic and water conditions and nutrient deficiency. The control equations were developed from Scots pine stands growing on post-agricultural lands in the close vicinity of the spoil heap. We found that equation type significantly influenced results of predicted biomass accumulation for all biomass components studied (although results were only marginally significant for total aboveground biomass, P=0.08). Total aboveground biomass in younger stands (6–9 years old) estimated using site-specific equations was >40% higher and for older stands (17–20 years old) from 7 to 27% lower than estimated using equations developed for the control sites. Our study revealed that under harsh environmental conditions in spoil heaps, biomass of young Scots pine stands significantly differ from values calculated based on control equations developed for more fertile soils with better water conditions in the same region. The control biomass equations may not be suitable to estimate biomass accumulation in stands growing on infertile habitats with poor water conditions, if the control equations are developed for nearby stands but growing under better site conditions.
Źródło:
Dendrobiology; 2014, 72
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fine roots biomass and morphology in a chronosequence of young Pinus sylvestris stands growing on a reclaimed lignite mine spoil heap
Autorzy:
Jagodzinski, A.M.
Kalucka, I.
Powiązania:
https://bibliotekanauki.pl/articles/2130192.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
root
biomass allocation
morphology
chronosequence
young plant
Pinus sylvestris
Scotch pine
stand
growing
reclaimed area
post-industrial area
mine dump
lignite mine
spoil heap
Opis:
The morphology of fine roots ( 2 mm diameter) as well as fine and coarse root biomass was investigated in a chronosequence consisting of 6-, 9-, 11-, 15-, 17- and 20-year-old Scots pine (Pinus sylvestris) stands growing on a reclaimed lignite mine spoil heap. Core method of destructive root sampling was used to establish whether root morphology and biomass varied with stand age in the upper 20 cm of soil. Fine root biomass ranged from 0.78 to 3.11 Mg ha-1, coarse root biomass ranged from 0.82 to 2.74 Mg ha-1, whereas root necromass ranged from 1.03 Mg ha-1 to 2.87 Mg ha-1 in the chronosequence studied. Fine root diameter as well as length, projected area, and surface area expressed per unit area increased significantly with stand age. Moreover, our study revealed that when stand age increases, specific fine root biomass increases, whereas specific root length and area decreases. The results support our hypothesis that stand age has an effect on standing fine root biomass and morphology.
Źródło:
Dendrobiology; 2010, 64; 19-30
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Productivity and economic effectiveness of young black locust tree stands on afforested sulphur opencast mine sites
Autorzy:
Likus-Cieślik, J.
Leńczuk, D.
Woś, B.
Lubera, A.
Pająk, M.
Pietrzykowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/28407528.pdf
Data publikacji:
2023
Wydawca:
Instytut Badawczy Leśnictwa
Źródło:
Folia Forestalia Polonica. Series A . Forestry; 2023, 65, 2; 86-95
0071-6677
Pojawia się w:
Folia Forestalia Polonica. Series A . Forestry
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of increased nitrogen depositions and drought stress on the development of young Norway spruce Picea abies (L.) Karst. stands
Autorzy:
Palatova, E
Powiązania:
https://bibliotekanauki.pl/articles/41235.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
forest tree species
plant development
Norway spruce
Picea abies
young tree
drought stress
nitrogen deposition
tree stand
biomass
fine root
functionality
mycorrhiza
Opis:
The effects of drought stress, stress by increased nitrogen depositions and the combined effect of the two stress factors on the growth of Norway spruce Picea abies (L.) Karst. were studied in two stands. The drought stress was induced by reducing atmospheric precipitations by 60% and the increased nitrogen depositions were simulated by repeated applications of ammonium sulphate at a rate corresponding to 100 kg N ha–1 year–1. All stress factors under study affected the height increment of the above-ground part, the length and colour of needles, and the biomass, vertical distribution, functionality and mycorrhizal infection of fine roots. The root system responded to the simulated stresses right from the the very first year of their action, exhibiting a greater damage than the above-ground part of the plant. Drought acted as a stress factor stronger than the nitrogen depositions themselves. The strongest impact was recorded in the simultaneous influence of the stress factors.
Źródło:
Dendrobiology; 2004, 51 Supplement
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preliminary assessment of the ecochemical condition of soils after fertilization of younger spruce Picea abies (L.) H. Karst. stands in the Beskid Slaski and Zywiecki Mts.
Autorzy:
Malek, S.
Januszek, K.
Barszcz, J.
Blonska, E.
Wanic, T.
Gasienica-Fronek, W.
Kroczek, M.
Powiązania:
https://bibliotekanauki.pl/articles/38500.pdf
Data publikacji:
2011
Wydawca:
Instytut Badawczy Leśnictwa
Tematy:
ecochemical condition
soil
fertilization
young tree
Norway spruce
Picea abies
tree stand
mountain
Beskid Slaski Mountains
Beskid Zywiecki Mountains
Opis:
The experimental plots were located in the middle forest zone (900– 950 m) on two nappes of the flysch Carpathians: Magura (the Ujsoły Forest District) and Silesian (the Wisła Forest District) in the spruce stands of age class 21– 40 years. Serpentinite was introduced in the autumn of 2008 on all plots while other fertilizers (N, P, NP and NPK) in the spring of 2009. Based on the chemical composition of soil solutions collected in lysimeters placed at the depth of 20 cm in the autumn 2008 and the spring and autumn 2009, ecochemical parameters were calculated: acid neutralization capacity (ANCaq), alkalinity (ALK), the degree of soil acidity (Ma%), acidic cations (Ma), saturation of the exchangeable complex of the soil solid phase (Mb) with alkalis, saturation with alkalis (BS), molar relations Ca/Al, Mb/Al, BC/Al. After the winter, soil solutions became acidic, especially in the Wisła Forest District. The saturation of the studied soils demonstrates moderate flexibility of soils in the Wisła Forest District in relation to acid load, and high flexibility of the Ujsoły soils. The opposite trend was observed for the degree of acidity of soils. Acid neutralization capacity and alkalinity of the waters showed significant variations in soil pH even in the case of small variations in the composition of the solution, if they were caused by the inflow of the anions of NO3 - and SO4 2-. After application of the fertilizers, an increase of Mg, Ca and Mb was noted in the soil solution, determined in the overlaying highly acidic organic horizons trough the ion-exchange buffering mechanism of highly protonated functional groups with high buffering capacity. Highly improved content of Mg in a soil, and in some cases – also the content of N, P and K, present potential improvement of forest growth capacity without the hazard of adverse side-effects of liming. Aluminum stress in the spruce is unlikely, while trees in the control plots in the Wisła Forest District may already be sensitive.
Źródło:
Folia Forestalia Polonica. Series A . Forestry; 2011, 53, 2
0071-6677
Pojawia się w:
Folia Forestalia Polonica. Series A . Forestry
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-9 z 9

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