DIGITALNA ARHIVA ŠUMARSKOG LISTA
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| ŠUMARSKI LIST 7-8/2012 str. 20 <-- 20 --> PDF |
structure of the old stands up to time of regeneration (reduction of oak trees due to mortality, thinning and the formation of secondary stand to preserve soil), and development of newly regenerated stands (denser, mixed stands and thus more stable), are projected. There are separate structure development models for four tree species: pedunculate oak (Quercus robur L.), narrow-leaved ash (Fraxinus angustyfolia), hornbeam (Carpinus betulus L.) and "other broad-leaved trees". Ranking and selection of stands or a part of stands according to regeneration priority are based on the economic criterion. The criterion means difference in potential revenue as a result of decision: prompt stand regeneration or adjournment of stand regeneration for 20 years. Habitat characteristics, structural and economic features of the stand are included too (Cavlovic et al. 2011a). As a base for a rough selection of part of stand for regeneration, the program uses inventory data (0.09 ha circular sample plots on network 100 * 100 m, each sample plot represent 1 ha of the stand). Calculation of the potential revenues during the projection period is based on the obtained relevant models of assortment structure and the prices of wood assortments, which are integrated in the program. Through a complex algorithm within the guidelines for the creating scenarios of future forest management (the maximum 10-year regeneration area, minimum and maximum area of the stand for regeneration, the minimum age of stands considered for regeneration, the minimum distance between regenerated stands), allows the numerous projections of the spatial and temporal forest development. Each step of the projection is showed on an interactive map that can display information for each 1 ha area or stand (group of 1 ha areas) separately (Figure 3, Figure 5). The basis of the spatial view is ESRI shape file that is required to set before creating the simulation. Plotting the spatial view is created by using GDI + programming instructions. The program is fully developed on .NET Framework 3.5 platform, using development tools Visual Studio 2008 and MS Access 2007 database. Used development language is C#. The SIMPLAG program provides information’s of the spatial and temporal forest development, development of age class distribution, stand development, amount and value of the revenues generated for each step of the projection, according to the different management scenarios. This information’s allow a comprehensive evaluation of a different management scenarios and selection of the most suitable management options. Key words: Pedunculate oak, projection of stand development, stand regeneration, management planning, selection of management scenarios |