Browsing by Author "Grodzki, Wojciech"

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    Do pheromone trapping always reflect Ips typographus (L.) population level? A study from the Tatra National Park in Poland
    (Sciendo (De Gruyter), 2021-03-13) Grodzki, Wojciech
    Pheromone traps are used for monitoring I. typographus populations in Norway spruce stands of the Tatra National Park (TPN) in Poland. The presented study is based on the set of pheromone traps of precisely known location (23) located in the whole area of the TPN and operated continuously in 2010–2019. The data on the captures of beetles were compared with two kinds of data concerning the mortality: the area covered by standing dead trees (airborne photographs) in the no-intervention zone, and the volume of trees infested by bark beetles processed in the active protection zone. No relationship was found between the mean numbers of beetles captured yearly in all pheromone traps in the whole TPN area and the volume of infested trees removed from the stands in the active protection zone. The captures in the two selected study areas were correlated with the area of spots with dead trees in the 500 m circle around the traps, however, this correlation is not statistically significant. There is no relation of captures to the volume of processed infested trees. The captures decreased in the growing seasons after the wind damage, and in creased markedly after the drought started in 2015. The results of pheromone trapping are affected by several factors, as wind damage and defence potential of trees resulting from their physiological status. Pheromone traps represent valuable source of information about the bark beetle I. typographus population dynamics, although the collected data do not enable direct definition of its population level, especially in the protected areas with different and unstable (changed in 2017) approach to the protection of stands. As most of the information on beetles is captured in the first half of the growing season, the data collected till the end of July are sufficient for monitoring purposes; thus, the trapping should be reduced to the period May–July.
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    On the vertical distribution of Ips duplicatus, I. cembrae and some bark- and longhorn beetles (Col.: Curculionidae, Scolytinae; Col.: Cerambycidae) in the Tatra National Park in Poland
    (Sciendo (De Gruyter), 2020-06-29) Grodzki, Wojciech
    In 2013–2014, a set of 30 pheromone traps baited with synthetic lures attracting I. duplicatus (Duplodor – 15 traps) and I. cembrae (Cembrodor – 15 traps) was installed in 6 altitudinal transects (1000–1400 m a.s.l., every 100 m of elevation) in the eastern, central and western part of the Tatra National Park (TPN) in Poland and operated during the entire growing season. The main aim of the survey was to check if and to what vertical extent these two species of bark beetles, not yet recorded, are presently distributed in TPN. Collected insects, including non-target Scolytinae and Cerambycidae, were determined. Overall 1896 Scolytid bark beetles belonging to 13 species, all occurring in the whole elevation range, were collected. I. duplicatus (28 specimens in total) was collected in the whole elevation profile, similarly as I. cembrae (718 specimens in total). Among Cerambycidae (282 individuals) belonging to 19 species, Rhagium inquisitor and Pidonia lurida, found on all elevations, were the most abundant; 8 species were collected on the highest locality. Pogonocherus decoratus was found for the first time in the Tatra. Results indicate the upward spreading of the studied insects as a possible effect of climate change and the resulting environmental conditions favourable for those organisms.
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    The European spruce bark beetle Ips typographus (L.) in wind-damaged stands of the eastern part of the Tatra National Park – the population dynamics pattern remains constant
    (Sciendo (De Gruyter), 2019-10-07) Grodzki, Wojciech; Fronek, Wojciech Gąsienica
    In March 2017, in the eastern part of the Tatra National Park in Poland, large windthrowns affected the passively and actively protected Norway spruce Picea abies stands. In early 2018, a set of 12 small research plots (20 trees on each plot) was established in the Norway spruce stands next to the windblown area – 6 in the stands under active nature protection (broken and fallen trees processed in 2017), and 6 in the stands under passive nature protection (trees left on the ground). Living trees on the plots were regularly checked during the growing season in order to identify and register the spruces infested by Ips typographus, which were dissected in 2 or 4 half-meter sections. 155 spruces (64%) infested by I. typographus were recorded on all 12 plots: 118 out of 120 (98%) in passive and 37 out of 120 trees (31%) in active protection. Mean infestation density calculated on 128 samples from 47 trees was higher under passive than under active protection (1.23 and 0.92 mating chamber per 1 dm2, respectively). Among 1709 gallery systems, those with 2 maternal galleries prevailed (63.0%); the mean share of females was higher in passive than in active protection zone (63.1 and 59.6% respectively). The mean number of progeny per one female was higher in active than in passive protection zone (20.23 and 19.12 respectively). I. typographus attack on standing trees had lower intensity in the stands previously subjected to the processing and removal of fallen and broken trees, which indicates positive effect of implemented active protection procedures. The parameters describing I. typographus population on attacked trees, as well as low activity of natural enemies, demonstrate its reproduction potential and resulting high risk of a new outbreak, according to the pattern known earlier from the other areas in Poland and Europe.