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Treść i zasady klasyfikacji siedlisk leśnych

100%
Sylwan
|
1992
|
tom 136
|
nr 08
47-49
This research regards the forests of Krynica surroundings (Western Carpathians). The object of the studies is to analyze the vegetal cover species in the undergrowth of deciduous mountain forest and mixed mountain forest, and to find floristic differences between these two types of forest environment. This subject was taken up because species indicating the type of environment in the Carpathian Region are useless in identifying the type of forest environments in Gorce and Beskid Sądecki Mountains. In the research, data from 50 model surfaces was used. In the studies the diagnostic value of indicator species, up to now used for forest environment identification, was judged according to their response for change in soil generosity of upper soil horizons. The types of soil found on model surfaces were divided into four groups, characterized by similar chemism of upper soil horizons (Fig. 1). Chemism of soil types in those groups is presented in Figure 2. The frequency of occurrence of different herb species depending on soil generosity is shown in Table 2. Specics of plants growing on soil of lesser generosity and receding as soil generosity increases, and those which became more frequent as the soil generosity increases, are useful to identify deciduous mountain forest and mixed mountain forest environments. Other species глге nearly useless for environment identification. It was also discovered, that species which became more frequent as soil generosity increases are joined by a significant correlation of coexistence (Fig. 3). Last phase of research defines forms of vegetal cover in forest undergrowth useful for differentiating between the two types of forest environment. Such forms are described by occurence of groups of plant species (lab. 3). It was found that the mixed mountain forest, growing on soil with upper horizons of low generosity, differs from the deciduous mountain forest by occurrence of plant species of Vaccinium group and lack, of Mercurialis group species. Typical mixed mountain forest, where upper soil horizons are of middle generosity, is similar to deciduous mountain forest because of presence of Mercurialis group species, but differs by occurrence of Vaccinium group species. The mixed mountain forest with upper soil horizons of high generosity docs not differ by floristic composition from the deciduous mountain forest. Soil generosity and productivity of both environments is caused by lower soil horizons.
In this study, the influence of species composition of tree stands of some chemical characteristics of leached brown, acid brown and cryptopodzolic soils, constituting the environ­ments of deciduous and mixed mountain forest, was studied. The soils of beechwoods, fir forests, spruce forests and spruce-larch-pine pioneer crops were compared. The soils of fir forests and beechwoods and been considered unchanged. Using these soils as norms fоr comparison, the degeneration changes taking place under spruce forests and pioneer crops were evaluated. The influence of improper tree stands was visible only in the humic-mineral horizons, where pH and base saturation decreased, and the types of humus became impoverished. Planted spruce forests and pioneer crops have not yet caused degradation of soils or environments. Probably, after the recreation of tree stands, the soils will spontaneously return to their natural condition.
14
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Siedliska lasow jodlowych Beskidow Zachodnich

63%
Praca nakreśla problemy, jakie napotyka się w gospodarce leśnej przy porównaniu jednostek klasyfikacji siedlisk wyróżnianych w dwóch systemach klasyfikacyjnych – typologicznym oraz fitosocjologicznym. Autorzy próbują wyjaśnić źródła tych problemów, a czasem nieporozumień. Praca zawiera ponadto propozycje odmiennego spojrzenia na relacje pomiędzy typami siedliskowymi lasu, a zespołami roślinnymi na obszarach niżowych, wyżynnych i górskich w Polsce.
The composition of isolated natural organic matter (NOM) fractions was studied by means of high pressure size-exclusion chromatography (HP-SEC), specific ultraviolet absorbance (SUVA) at 254 nm, total luminescence spectroscopy (TLS) and synchronous scanning fluorescence measurements. The HP-SEC, SUVA and TLS studies revealed that humic acids (HA) and hydrophobic acids (HOA) are composed of complex, aromatic and high molecular weight subunits. Hydrophobic neutrals (HON) consist of few groups of compounds with relatively low molecular sizes and a degree of condensed aromatic moieties. Similar characteristics were observed for hydrophilic acids (HIA) and bases (HIB). Obtained results also demonstrated that hydrophilic neutrals (HIN) are made of non-humic, aliphatic and low molecular weight components. Furthermore, the synchronous excitation-emission spectra indicated the presence of proteinlike constituents in HIB, HIN and HON fractions as well as lignin-derived constituents with relatively low molecular sizes in HIA.
Sylwan
|
1999
|
tom 143
|
nr 11
89-97
20
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Tocopherol content in edible plant oils

51%
Edible vegetable oils were analysed for tocopherols by reversed-phase HPLC. These included refined corn, soybean, sunflower, rapeseed, grapeseed, and peanut oils, and cold-pressed extra-virgin olive, linseed, rapeseed, and sunflower oils. Total measured tocopherol concentrations varied in the range from 121 to 829 mg/kg. The contents of individual α-, (β+γ)-, and δ-tocopherols show a great diversity depending on the kind of oil. Moreover, the effect of photooxidation on the tocopherol content was studied in cold-pressed sunflower and rapeseed oils. These studies revealed only a minor decomposition of tocopherols under visible light.
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