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One of the concepts of global protection of environment is to reduce greenhouse gas emissions, mainly carbon dioxide, into the atmosphere by replacing fossil fuels by the so-called biofuels, which can be obtained from cultivated plants or any plant waste biomass. Currently applied industrial technologies allow the production of biofuels to receive ethanol, mostly from the reserve carbohydrates of sugar cane and corn as well as biodiesel from oil, mainly from rapeseed or oil palm. Tobacco, which provides a high biomass, can be used to produce biogas, bioethanol and biodiesel. The latter derived from oil from seeds and leaves of tobacco has proved useful for driving cars. Modest oil content in tobacco leaves can be increased by the expression of foreign genes encoding its biosynthesis. Promising future source of biofuels is a waste plant biomass consisting mainly of cell walls, which can be subjected to the degradation to produce sugars suitable for fermentation and the production of bioethanol. A number of enzymes needed for efficient degradation of plant cell walls can be produced using recombinant DNA technology in a variety of plants, particularly in chloroplasts of tobacco.

Wood obtained from freshly cut trees has a high moisture content and therefore its mass per volume unit is higher than the mass of dry wood. The natural drying is a simple and effective method of weight (moisture content) reduction, making a better use of the vehicle's payload, and thus reducing costs, including environmental costs. The conclusion is based on simulations and analyzes attempting to evaluate different solutions. As evidenced, the drying process of logs depends on numerous factors, which entails attempts at development of an optimal logging method, especially concerning energy wood, allowing for maximum value growth in as little time as possible. The suggestions cover various forms of logging (of whole trees, long timber), arranging (in piles, bundles), storing (in stands, by the roadside near cutting areas), and protection. Combined methods such as storing under canvas for winter only or storing in cutting areas and later in piles at the exit road also work in practice, but require more funds because their cost is determined by the number of stages composing the whole process. In case of wood, development of an optimal and simultaneously universal method used to prepare the lumber for transport and its delivery with consideration of as little environmental impact as possible is complicated. The numerous variables, some of which cannot be controlled or affected, create a considerable scientific problem as well. The authors covered in the presented literature review often stress the role of specific weather conditions accompanying an experiment or its location, the storage method, or lumber dimensions in the drying process. Storage time is perceived as equally important, but it is a derivative more or less determined by the previous variables. Previous studies of drying at the cutting area have been focused mainly on energy wood and less on industrial wood. They analysed the results of long−term storage and did not stress the potential advantages of short−term drying. Furthermore, we do not have sufficient information on species, including forest trees, which have a lower share in the volume of the logged wood. Advanced research can help establish the minimum mass (moisture content) with considerable impact on supply chain effectiveness improvement or evaluated various storing and drying methods. We reviewed reports explaining the impact of various factors on natural drying of wood, models and storage effects, and analyzing potential economic and environmental benefits. Sylwan 161 (11): 898-908

So−far developed and published Polish equations for determination of aboveground biomass of Scots pine are based on two predictors: diameter at the breast height (DBH) and tree height. The main goal of the presented study were i) to build the simplified empirical biomass equations that use exclusively DBH as the independent variable, and ii) to compare the obtained results with values from equations based on both predictors (optimal model). The empirical material consisted of biomass data for 90 Scots pines growing on typical habitats in Bory Lubuskie (western Poland). The elaborated equations have a lower accuracy than the optimal ones. The R value for all biomass components is higher than 0.69, and reaches as much as 0.976 in the case of dry wood biomass. The root mean square error (RMSE) for such components as dry biomass of bark and alive or dead branches and branches with needles is lower for the simplified model. However, for the dry wood biomass the optimal model has lower RMSE value. Because this component has the largest share in the total aboveground tree biomass (AGB), the resulting RMSE for the AGB is lower than for the optimal model. Optimal model is also more accurate when the mean error is considered. The simplified model can be used when there are no height measurement available or there is an anxiety that the use of height−diameter models significantly increases the uncertainty of results. Sylwan 160 (4): 277-283

Bacillus thuringiensis israelensis (Bti) has been developed into many products for the biological control of dipteran larvae, including mosquitoes (Culicidae), black flies (Simuliidae), and midges (Chironomidae) in various parts of the World. Bti appears to pose significantly less of a risk than other chemical pesticides used for mosquito control and eradication programs. Bioproducts based on Bti are highly selective with short environmental persistence, and thus they have very little potential to cause damage to populations of non-target organisms. So far, no example of an unexpected pathogenic organism being developed in the field as well as no examples of resistance to Bti both laboratory and field populations of mosquitoes have been documented. There are some indications that large declines in insect biomass can occur after long-term use of Bti in freshwater wetlands. However, no evidence for permanent damage to ecosystem function has been found. Organisms that utilized insects for food, adapted to the declines and either switched to other food sources or migrate (birds) outside of the treated zones to acquire insects. Even though over 40 tons of Bti have been applied in West Africa alone, no indications of human health or non-target effects have been reported.

In laboratory conditions the influence of Diesel fuel oil on the total number bacteria, fungi, actinomycetes and content of microbial biomass in soil was studied. The fuel oil was applied at dosage of 1, 2 and 5 g/100 g of soil. Samples of soil were analysed 1, 7, 14, 21 and 150 days after oil applied. Microbiological analyses involved determinations of the total number of bacteria and actinomycetes (on Bunta-Roviry medium) and fungi (on Martin's agar) by the plate method. The content of microbial biomass in soil was determined using the physiological method of Anderson and Domsch. Diesel fuel oil application caused the changes of total number of investigated groups of soil microorganisms. These results were confirmed by the investigated groups of soil microorganisms. These results were confirmed by the investigation on microbial biomass in soil. In the most of cases the fuel oil was the most stimulated for the number of bacteria and the most inhibited for actinomycetes in comparison with soil without oil (control). From soil with Diesel fuel oil addition Pseudomonas, Arhtrobacter, Bacillus and Penicillium, Aspergillus, Fusarium, Trichoderma strains were isolated. The possibility of the fuel oil as source of carbon utilization by these strains will be investigate.

Recent changes in the natural and social environments require new solutions regarding the management of Scots pine (Pinus sylvestris L.) stands, i.e. one of the key forest−forming and economically−important tree species in Europe. The long tradition combined with efforts to perfect the management by clear−cutting, there is still a search for alternative methods of managing in all European biogeographical regions, in which Scots pine plays a leading role. Regeneration and renewal over large areas is difficult to achieve (Mediterranean or boreal regions). And even in places where it remains possible, it can end up with large, even−aged stands of inevitably simplified structure, which prove highly, and perhaps increasingly, vulnerable to damage from both abiotic (frost or windthrow) and biotic (pathogenic fungi and insect pests) agents. These management methods also generate abrupt change in the forest landscape and, while this actually just represents advantage being taken of the natural capacity of pines to reoccupy extensive cleared areas (such as those following fires or gales), it frequently now proves unacceptable to the public. This is seen in particular in the areas around large cities or nature protection areas. The aim of this article is to review both traditional and alternative means of management of Scots pine stands within three largest biogeographical regions of Europe. While obviously relating to the environmental conditions holding sway in these different regions, silviculture in pine stands is based around a similar spectrum of applied methods that favour the emergence of single−, double− or multi−generation stands. In the boreal region, where the species finds suitable conditions for its growth, we search for effective methods to imitate small−scale natural disturbances, initiating the regeneration within gaps of differing sizes. In turn, in the continental region, research focuses on devising methods to make full use of natural regeneration, as well as seeking to limit the negative effects of clear− −cutting in the forest landscape, e.g. by leaving seed or residual trees, and clumps of the old−growth. Here too, the alternatives to clear−cutting may lie in partial or full felling being confined to smaller areas; as well as in the gradual inclusion within the main stand of trees regenerating successfully beneath the tree canopy. Finally, in the Mediterranean region, where the main factor limiting regeneration is drought, various shelterwood−felling variants are applied to fully benefit from the shielding that the mother stand offers. All the regions witness more and more frequent restrictions on the use of management means based on clear−cutting, with wider use of alternative silvicultural methods looking inevitable in the near future, in the context of both climate and social change. The need to compromise between the production−related and other functions of pine stands, and to devise generally−acceptable methods for their management, are now among the more−difficult challenges facing European forestry. Sylwan 165 (5): 355-370

A bibliographic review is presented on publications related to bioaccumulation of elements, specially metals and radionuclides in fruiting bodies of higher mushrooms collected at the territory of Poland. In the paper apart from the list of references in tables is given, chronologically, name of the first author, year of publication, site, the type of work (in situ, commercial source, field experiment, laboratory study), chemical symbols of the elements and the abbreviations of the latin names of the mushroom species under study.