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When using the unique in terms of the volumes of database on the level of a stand of the genus Larix Mill., the trans-Eurasian additive allometric models of biomass for Eurasian larch forests are developed for the first time, and thereby the combined problem of model additivity and generality is solved. The additive model of forest biomass of Larix is harmonized in two levels, one of which provides the principle of additivity of biomass components, and the second one is associated with the introduction of dummy independent variables localizing model for eco-regions of Eurasia. Comparative analysis of the biomass structure of larch stands of different ecoregions at the age of 100 years shows, that the greatest values of biomass (210-450 t/ha) correspond to the regions adjacent to the Atlantic and Pacific coasts, as well as to the regions, located at the southern limit of larch growing area and the lowest – to northern taiga regions of Siberia, where larch grows on permafrost. The biomass indices of different ecoregions differed not only in absolute value but also in biomass ratios of different components; for example, the proportion of needles in the aboveground biomass is maximum (5.0-7.3%) in the northern taiga of Central Siberia and the Far East on permafrost and is minimum (1.4-1.9%) in larch forests of upper productivity having biomass values 210-450 t/ha. The proposed model and corresponding tables for estimating stand biomass makes them possible to calculate larch stand biomass on Eurasian forests when using measuring taxation.
On the basis of the compiled database in a number of 3020 sample plots with determinations of forest biomass of two-needled pines (subgenus Pinus) on theterritory ofEurasia fromGreat Britain to southernChina andJapan statistically significant transcontinental gradients of stem, roots, aboveground and total biomass are established. In the direction from North to South these biomass components change according to a bell-shaped curvewith a maximum in the third (the southern temperate) zonal belt, while the biomass of needles, branches and understory is monotonically increasing within this zonal gradient from subarctic to subequatorial zonal belts. In the direction from the Atlantic and Pacific coasts to the continentality pole inSiberia there is a biomass decrease as of all components of the wood story and the understory. The root: shoot ratio increases in the range between subarctic and southern temperate zone from 12 to 22% and then decreases to 16% in the subtropical zone, and within the southern temperate zone it monotonically increases from 20% on the oceanic coasts to 23% near continentality pole. The ratio of understory biomass to wood story biomass reduced from 4.0 to 2.5% ranging from subarctic to southern temperate zone and then rises to 3.5% in the subtropical zone, and within the south temperate zone it monotonically decreasing from the maximum value of 22% near Atlantic and Pacific coasts, approaching the level of 2-3% near the continentality pole. The results can be useful in the management of biosphere functions of forests undoubtedly.
The analysis of the biomass of larch (genus Larix spp.) trees on the total component composition based on regression equations having the additive biomass structure. Two trends of changes in the tree biomass structure are revealed: due to the mean January temperature and due to the mean annual precipitation. It was shown for the first time that both trends are mutually determined: the intensity of biomass trend in relation to the temperature is changing when depending on the level of precipitation, and the intensity of biomass trend in relation to precipitation level is changing during to a transition from the cold zone to the warm one and vice versa.
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