DIGITALNA ARHIVA ŠUMARSKOG LISTA
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|ŠUMARSKI LIST 5-6/2018 str. 13 <-- 13 --> PDF|
Natural regeneration of plants – Prirodno pomlađivanje biljaka
Natural regeneration of plants which were germinated after making salvage cutting was determined at three large and three small forest gaps and in the control plots. Each forest gap was covered with a net, 5 x 5 m. The initial point of the net was the gap centre. At the intersections of this net, test plots of 1.5 x 1.5 m were installed. A total of 35 test plots were installed in the three large gaps and 31 plots in the edge areas of the large gaps, and a total of 17 test plots were installed in the small gaps and 13 plots in the edge areas of the small gaps. A total of 243 test plots (1.5 x 1.5 m) were installed in the control plots (forest stands). In each test plot, plants were counted and the species recorded. Plants were divided into one group of small seedlings which is up to three years of age or to a height of 20 cm (Prpić and Seletković 2001, Rozenbergar et al. 2007).
Data processing – Obrada podataka
All microclimate data were processed using the HW3 and SpecWare 9 professional programs. Statistical processing of microclimate data, and density of plant regeneration in the forest gaps, in the gap edge areas and the control plots was carried out by the analysis of variance (Repeated measures ANOVA, One-way ANOVA, post hoc Fisher LSD test). The Pearson correlation coefficient was used to determine the relationship between individual microclimate elements measured and the relationship of microclimate elements and the density of small seedlings. The statistical programs Statistica 7.1. (StatSoft Inc. 2003) was used for statistical data processing.
In the observed period, the mean air temperature was 8.98°C in the large forest gap, and 8.80°C in the control plots. The difference in the mean value of relative air humidity was 0.2%. No statistically significant differences were determined for air temperature or relative air humidity between the large forest gap and the control forest stand. Considerable differences were determined in soil temperatures in the control forest compared to the large forest gap and its edge areas. The mean value of the soil temperature was 8.48°C in the control forest, and 9.14°C in the large forest gap. Significant differences were also determined in volumetric soil water content between the control forest, large forest gap and its edge areas. The mean value of volumetric soil water content was 14.48% in the control forest, and 13.29% in the forest gap (Table 2). The mean air temperature did not differ significantly between the small forest gap and control forest stand. A significantly higher value of relative air humidity was determined in the small gap (79.45%) compared to the forest stand (78.55%). Significant differences were also determined between soil temperatures in the forest stand and in the gap edge area as compared to the mean soil temperature in the small forest gap. The highest soil temperature (8.68°C) was recorded in the forest gap. No significant difference was found between soil temperatures in the forest stand and forest gap edge area. Significant differences were found in the volumetric soil water content between all sites. The mean value was 13.49% in the forest gap edge area, and 16.0% in the forest gap (Table 2).
As shown in Table 3, the mean air temperature did not significantly differ between the small and large forest gaps. Relative air humidity was 79.45% in the small forest gap, which was considerably higher than in the large forest gap (77.28%). Soil temperature was significantly higher in the large gap area and its edge area compared to the small forest gap. Volumetric soil water content was 16.0% in the small gap, which was significantly higher than in the large gap (13.29%). Volumetric soil water content in the gap edge area of the large forest gap was significantly higher and amounted to 14.02%. Daily average values of soil temperature and volumetric water content over a two years period