engleski

Can air pollution influence spruce bark beetle populations in the Central European muntains ?

The possible role of industrial pollution as a factor predisposing spruce stands to attack by bark beetles, mainly Ips typographus L., is poorly understood. The abundance fluctuation of I. typographus populations were evaluated in above 60-years old Norway spruce stands occurring on 2 more and less polluted sites in Slovakia and Poland in the Carpathians in 1998-2000. Bark beetle populations were estimated periodically each year in 50 ha plots using a series of pheromone traps and through the dissection of 0.5 m sections of infested trees. Data were recorded based on several parameters including the volume of infested trees, captures in pheromone traps, and the number of entrance holes. The results of analyses indicate: sanitary cuttings were significantly higher in stands ranked as more polluted ; statistically higher captures were also found on plot ranked as more polluted ; differences in infestation densities on trees were not significant in Slovakia, but were significant in Poland (however trees on less polluted plots were more infested). In the period 2000-2001 3 transects were established in High Tatras, where captures in pheromone traps were recorded and compared to air pollution represented by ozone concentrations. The results of correlation analyses (using the transformed data of captures to pheromone traps vs. O3 concentrations) indicate, that variance in captures should be partially explained by O3 concentrations (however significance of correlation coefficients was not found). Analyses of variance also indicates differences in average captures among transects characterised by different ozone concentrations.

bark beetles; abundance fluctuation; air pollution; Norway spruce; ozone

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