226 research outputs found
Barriers and bridges for intensified wood production and biodiversity conservation in NW Russia's boreal forest
Wood production and biodiversity conservation are two key objectives of sustainable forest management policy. These goals are rival and, therefore, hard to achieve at the same time and space. The aim of the thesis is to contribute to the understanding of barriers and bridges for intensified wood production and biodiversity conservation in NW Russia’s boreal forests. It was implemented by case study approach on both ecological and social systems of forest landscapes with different forest use histories in the European boreal biome.
I first studied the forest use history in a forest management unit in NW Russia (paper I). Second, I analysed how production and biodiversity goals are actually balanced on the ground by comparing indicators for wood production and biodiversity conservation in NW Russia, Belarus, Latvia and Sweden (paper II). Next, in order to test the hypothesis that there are no biophysical obstacles to intensified wood production in NW Russia, I compared tree growth rates at 4 latitudes in NW Russia and Sweden (paper III). Finally, I reviewed the history of forest zoning policy, which is an influential mechanism to conserve biodiversity in Russian forests, and assessed if zoning policy change towards intensification negatively affected riparian forests, e.g. biodiversity conservation (paper IV).
Results from this research shows that barriers for intensified wood production in NW Russia include limited silviculture, poor road development and conservative mind-set of decision-makers (paper I). Bridges for intensified wood production involve existing infrastructure of forest villages and available middle-aged forests (paper I) as well as equal biophysical conditions for tree growths (paper III). Biodiversity conservation goal is achieved better than wood production in NW Russia in comparison to countries with longer forest use histories (paper II). More relaxed zoning policy is considered as barrier to biodiversity conservation (paper IV). Developed zoning system (paper IV), landscape approach initiatives and remaining intact forests (paper I) provide opportunities for biodiversity conservation.
This thesis suggests that balanced sustained-yield wood production together with biodiversity conservation is possible when a segregative zoning model is employed. To conclude, there is a need to engage in transdisciplinary research on the role of landscape stewardship for satisfying both wood production and biodiversity conservation objectives
Chemical composition ana parameters on crystallization the Southern trachybasalts: : Evidence from and fluid inclusions
Extended Rein-Sehgal model for tau lepton production
The polarization density matrix formalism is employed to include the final
lepton mass and spin into the popular model by Rein and Sehgal for single pion
neutrinoproduction. We investigate the effect of the lepton mass on the
differential cross sections. The lepton polarization evaluated within the
extended RS model is compared against that follows from the single resonance
production model based upon the Rarita-Schwinger formalism with
phenomenological transition form factors.Comment: Contribution to the 3rd International Workshop on Neutrino-Nucleus
Interactions in the Few-GeV Region, 17-21 March, Gran Sasso (Italy
Intensifying forestry in NW Russia?
Inspired by Fennoscandian forestry, current Russian forest policy advocates intensification to reach higher sustained yields of wood as a base of economic growth. This requires knowledge about the consequences of regional forest histories, about the biological opportunities for tree growth, and about society. Focusing on a regional logging frontier in the Komi Republic in NW Russia we studied the history of wood use in terms of landscape changes, actors and their ideology. Past wood mining resulted in large areas of unmanaged young and middle-aged forests dominated by birch and aspen, and remnants of remotely located older spruce forests. To understand if biological conditions in NW Russia limit tree growth, we compared tree growth rates of young Scots pine and Norway spruce trees at different site types and latitudes in NW Russia and Sweden. While there was no difference in growth rate of young Scots pine between countries, Norway spruce grew more slowly in NW Russia. However, it was difficult to find young spruce trees growing freely without competition. Spatial planning is needed to segregate intensified wood production and forest management that also benefits rural development and biodiversity conservation. Ultimately, to succeed with intensification in the context of sustainable forest management also economy and society must be studied
Origin of the Laleaua Albă dacite (Baia Sprie volcanic area and Au-Pb-Zn ore district, Romania): evidence from study of melt inclusions
Crystal inclusions (plagioclase, biotite, magnetite) and melt inclusions were studied in minerals of the Laleaua Albă dacite (Baia Sprie, Romania). Electron microprobe analysis of 29 melt inclusions in the plagioclase, K-feldspar, and quartz confirm that crystallization of these minerals took place from typical silicic melts enriched in potassium relative to sodium (K2O/Na2O = 1.5). The sum of the petrogenic components is 92–99 wt%. This points to a possible change in water content from 8 to 1 wt% during crystallization of phenocrysts. According to ion microprobe analysis of 11 melt inclusions, the minimum water content is 0.5 wt%, and the maximum water content is 6.1 wt%. The presence of high-density water fluid segregation in one of the melt inclusions suggests that the primary water content in the melt could reach 8.4 wt%. Ion microprobe data revealed a high concentration of Cu (up to 1260 ppm) as well as higher U content (from 5.0 to 14.3 ppm; average 11.5 ppm) in some melt inclusions as compared to the average U contents in silicic melts (2.7 ppm in island-arc settings and 7.9 ppm in continental rift settings). Chondrite-normalized trace-element patterns in melt inclusions suggest a complex genesis of the studied magmatic melts. Contents of some elements (for instance Sr and Ba) are close to those in island-arc melts, while others (for instance Th, U, and Eu) resemble those in melts of continental settings
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