PL
W pracy przedstawiono kształtowanie się przyrostu grubości drzew w 40, 60 i 90-letnich drzewostanach sosnowych, rozwijających się w różnych strefach zagrożenia trzech regionów przemysłowych: Tarnobrzeskiego Zagłębia Siarkowego, Legnicko-Głogowskiego Okręgu Miedziowego oraz hutу cynku i ołowiu w Miasteczku Śliskim. Określono również krzywe modelowe przyrostu grubości drzew w zależności od klasy wieku drzewostanu i strefy zagrożenia.
EN
The purpose of this study was to characterize the current annual increment of d.b.h. radius of trees in 40, 60 and 90-year-old Scotch pine stands situated in different danger zones of three industrial regions: the Tarnobrzeg Sulphur Basin (TZS), the Legnica-Głogów Copper District (LGOM), and zinc and lead smelting works in Miasteczko Śląskie (MŚL). The study material in from of icrement borer cores taken from every fourth tree was collected in 62 experimental sites (Table 1). Mean increment of d.b.h. radius was calculated for each urea for two 25-year increment periods. First (x1) comprised the period 1968-1992, i.e. the period when stands were developing under the effect of industrial immisions, and second (x2) for the period 1943-1967, i.e. before the occurrence of harmfull factor (Table 2). The dynamics of diameter increment drop was determined using drop coefficient (W) according to formula 3 (Table 2). The course of current diameter increment (Figs. 1-3) was balanced using six different formulae (I-IV). One formula was selected (formula II) and used to determine a model course of diameter increment (Table 3, Figs. 4, 5). The results obtained permitted to draw the following conclusions: 1. Current annual increment of d.b.h, radius during the last 25 years (x1) depended on age of a stand and amounted to 1.11 -1.52 mm in 40-year-old stands. 0.99- 1.15 mm in stands 60-years-old, and 0.78-0.81 in stands 90 years of age. 2. Magnitude of increment and its drop depended on stand age and danger zone, i.e. the increment decreases, and the drop increases as the threat to forest stand increases. 3. Course of the current annual increment of d.b.h, radius after its culmination is represented by function with formula у = a + b/w (formula II), and the model curves drafted on its basis may serve in evaluation of increment course in individual industrial danger zones.