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Age-related changes in leaf area index of young Scots pine stands

100%
Jagodzinski A. M., Kalucka I.
Dendrobiology
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2008
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tom 59
57-65
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.
2

Stem volume and aboveground woody biomass in noble fir [Abies procera Rehder] stands in the Rogow Arboretum [Poland]

80%
Jagodzinski A. M., Banaszczak P.
Acta Scientiarum Polonorum. Silvarum Colendarum Ratio et Industria Lignaria
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2010
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tom 09
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nr 2
9-24
The study was carried out in 39- and 43-year-old stands of noble fir (Abies procera Rehder) grown in the Rogów Arboretum of the Warsaw University of Life Sciences (Poland). The main objectives of our study were (1) to estimate stem volume over bark of noble fir grown out of its natural range, (2) to develop suitable allometric equations for estimating aboveground woody biomass components and (3) to estimate aboveground woody biomass components using site-specific allometric equations and to compare them with biomass estimated using allometric equations developed in stands grown within natural range of noble fir. The study showed that the mean DBH of trees was 20.14 cm in the younger stand and 22.25 cm in the older stand. The basal area of the 39-year-old stand was 49.01 m2·ha-1 and 43-year-old stand was 47.53 m2·ha-1. Based on the developed equation stem volume over bark was 374.87 m3·ha-1 and 356.24 m3·ha-1 in the 39- and 43-year-old stands, respectively. Based on the developed site-specific allometric equations total aboveground woody biomass in the 39-year-old stand was 189 Mg·ha-1 whereas in the 43-year-old stand it was 184 Mg·ha-1. Branch biomass in both stands equaled 19.9% of total aboveground wood biomass. Total aboveground woody biomass, estimated by allometric equations published by Ter-Mikaelian and Korzukhin [1997], equaled 233 Mg·ha-1 and 228 Mg·ha-1 in the 39- and 43-year-old stands, respectively. This means that the aboveground woody biomass is overestimated by ca. 23% in comparison with biomass estimated by our site-specific allometric equation. Generally, the existing equations published by Ter-Mikaelian and Korzukhin [1997] overestimated total aboveground woody biomass and stem biomass, while branch biomass was underestimated across all tree sizes compared to directly obtained biomass data.
3

Allometric models of foliage biomass in Scots pine (Pinus sylvestris L.)

80%
Jelonek T., Pazdrowski W., Walkowiak R., Arasimowicz-Jelonek M., Tomczak A.
Polish Journal of Environmental Studies
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2011
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tom 20
|
nr 2
Presented analyses were connected with modelling foliage biomass of Scots pine (Pinus sylvestris L.) growing in northern and western Poland. In order to realize the study, a total of 38 one-hectare experimental plots were established in commercial pine monocultures growing on sites optimal for this species at a given geographical location. A total of 114 trees aged 32-114 years were felled and their needle weight and the weight of needles and young, 1-year old twigs were measured. Since social variation in the stand could affect the fit of the model, for each social class of tree position an individual allometric equation was proposed, based on easily measurable biometric traits of trees. Analysis of stepwise backward regression was conducted in order to determine variables in these equations. It turned out that to estimate foliage biomass of predominant and dominant trees, it seems most appropriate to apply diameter at breast height and tree age. In turn, for co-dominant trees, apart from diameter at breast height and tree age, the model needs to include additionally tree height and crown length. Moreover, due to the fact that the dependence between needle weight and the weight of needles and young twigs is practically linear, prediction was conducted for the biomass of foliage with young twigs. From the practical point of view, this makes it possible to precisely determine needle biomass on the basis of the weight of needles with young, 1-year-old shoots.
4

Size of the upper respiratory tract with reference to the body in scaup Aythya marila

80%
Pierko M.
Electronic Journal of Polish Agricultural Universities. Series Biology
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2008
|
tom 11
|
nr 4
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