Scheduling and regulation of the forest use are of much importance in forest management. Decisions regarding the manner, timing, and intensity of tree felling result in long-term effects, as these affect the species and age structure of forests, along with the direction and dynamics of changes in forest resources. Above all, serious doubts concern the way of determining and accounting for the prescribed forest utilization, and in particular, the possibilities of the pre-final cuttings. In recent times, the precise determination of the pre-final cuttings by volume has been given up. According to the law, the area of pre-final cuttings is now obligatory taken into account. Consequently, it is not possible to determine the total volume limiting the amount of timber to be harvested, thus, there is decreased the value of the forest management plan as the document approved by the minister responsible for forestry as well as the basis for forest management. For practical reasons, the specified pre-final cuttings by volume are considered as indicative.Connecting the planned pre-final cutting volume with the expected volume increment of the stand has not been relinquished. In the present paper, the authors called attention to a necessity for further improvement of the mediumterm planning of pre-final cutting volume. A need to change the definition of the incidental cutting was emphasized. As said by the authors, the term "incidental cutting" should denote harvesting wood from diseased and dying or dead trees, along with eliminating the effects of tree damage caused by fortuitous events. Accordingly, the incidental cuttings that are inherently unpredictable, should not be directly attributed to pre-final cutting products. Keeping in mind the incidental cuttings, the authors proposed the method of reckoning the forest use, which would allow for correct accounting with regard to the prescribed pre-final cuttings. Key wordsforest management plan, planning and regulation, pre-final and final cuttings, incidental cutting Unauthenticated Download Date | 5/13/18 8:17 AM

In modern forestry, the complexity of the planning process is increasing, specifically in the context of the sustainable use of forest resources and its adaptation to climate changes. This article presents the concept of forest use regulation promoting the sustainable forestry development in forest management planning. A method for defining a synthetic criterion of assessing important features of stand structure was proposed, which would enable the classification of stands in terms of needs and the urgency of their transformation (reconstruction) or suitability for longer standing. As a result, such a concept may ensure the preservation of the relative uniformity of logging use and the improvement of age structure as well as an increase of natural values of the forest, regardless of a stand’s age. The concept was tested on a large forest complex (over 0.5 million hectares) subjected to intense environmental pressure (Silesian Region in Poland). We prepared long-term individualistic development forecasts, separately for area and volume. Based on this, we followed the cutting uniformity principle in the analysed time period by calculating a long-term average of cutting allowance. It was determined by averaging the projected usage size in moving window and eventually was adopted as the cutting upper limit in the whole analysed period. The proposed size of cuts in each period resulted from the relation between the average value and the forecast. Three sets of stands of the differentiated urgency of interventions were distinguished: I—well-stocked and stable stands (no need of intervention)—55% of stands area, II – acceptable stands (not urgent intervention needed)—35% and III—poor stands (urgent intervention needed)—10%. This concept joins top-down and bottom-up approach of cutting uniformity that focuses stand’s status instead of its age or dimensions.

Single-phase Pr 2 CBr was prepared by heating a mixture of PrBr 3 , Pr and C (1 : 5:3) to 1140 • C for 18 d. The crystal structure was investigated by X-ray single crystal diffraction (space group P6 3 /mmc, a = 3.8071 (3), c = 14.7787(12)Å). In the structure the Pr atoms form C-centered octahedra condensed into Pr 2 C sheets via common edges; these sheets are separated by the Br atoms which are in a trigonal prismatic environment of Pr atoms. Pr 2 CBr is a black shiny compound with metallic conductivity. It is a ferromagnet with T c = 13.8(5) K.

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