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Abstract: The northern spruce bark beetle, Ips duplicatus (Sahlberg), has invaded Central Europe in the past century and continues to spread southwards and westwards. It has caused damage in some parts of Europe in recent decades and poses a serious threat to spruce forests across the continent. From 2018 to 2021, we conducted intensive monitoring to determine the status of I. duplicatus in Slovenia. We used different types of traps and pheromone lures that attract I. duplicatus beetles and took bark samples from bark beetle-infested trees. Of the 26 traps used during the four years of monitoring, I. duplicatus was found in 16 traps in the central part of Slovenia in 2020. Adult beetles were caught in traps containing both I. typographus and I. duplicatus lures. The identity of this species was confirmed using morphological keys and molecular methods. One to five I. duplicatus beetles were found per trap, totaling 25 specimens. However, we did not confirm any I. duplicatus in samples taken from trees in 2021. We conclude that I. duplicatus is present in Slovenia, but our results suggest that the species is only present locally and that the population is small.
Keywords: biological invasions, forest pests, temperate forests, conifers, damage, forest pest monitoring, confirmation
Published in DiRROS: 05.09.2023; Views: 342; Downloads: 159
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Keywords: nematode, expansin-like protein, expansin, potato cyst nematode, potato pest, parasitic nematodes, plant celular function
Published in DiRROS: 06.09.2022; Views: 474; Downloads: 202
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Abstract: The European spruce bark beetle (Ips typographus L.) is an eruptive forest pest that has caused a great deal of damage in the last decades because of increasing climatic extremes. In order to effectively manage outbreaks of this pest, it is important to predict where they will occur in the future. In this study we developed a predictive model of the sanitary felling of Norway spruce (Picea abies (L.) H. Karst.) because of bark beetles. We used a time series of sanitary felling because of bark beetles from 1996 to 2020 in Slovenia. For the explanatory variables, we used soil, site, climate, geographic, and tree damage data from the previous year. The model showed that sanitary felling is negatively correlated with slope, soil depth, soil cation exchange capacity, and Standard Precipitation Index (less sanitary felling in wet years). On the other hand, soil base saturation percentage, temperature, sanitary felling because of bark beetles from the previous year, sanitary felling because of other abiotic factors from the previous year, and the amount of spruce were positively correlated with the sanitary felling of Norway spruce due to bark beetles. The model had an R2 of 0.38. A prediction was performed for 2021 combining an occurrence model and a quantitative model. The model can be used to predict the amount of sanitary felling of Norway spruce due to bark beetles and to refine the risk map for the next year, which can be used for forest management planning and economic loss predictions.
Keywords: sanitary felling, prediction, Ips typographus, Picea abies, Slovenia, forecasting, insect outbreak forest pest
Published in DiRROS: 21.02.2022; Views: 629; Downloads: 518
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Abstract: In the last few decades, an increasing number and intensity of bark beetle outbreaks have plagued the forests of Europe and North America. Bark beetle management is directly related to forest owner characteristics, although this relationship is not well understood. The purpose of the study was to investigate the influence of forest owner characteristics on the amount and timing of sanitary felling under different disturbance regimes and quantities of Norway spruce. We combined different databases on sanitary felling, the timing of sanitary felling, and forest owner characteristics for Slovenia from 2014 to 2018 and analyzed the amount and timing of sanitary felling in relation to forest owner characteristics. We found that the timing in winter and the amount of sanitary felling were positively associated with the distance of the owner%s residence to the forest parcel. Larger parcels were more affected by bark beetles but did not have later timing of cutting in the summer period as was hypothesized. The timing of sanitary felling decreased with property size, while with the probability of sanitary felling, the effect of property depended on the ice storm and the amount of spruce. The size of the settlement, the permanent address of the private owner, and timing of sanitary felling were positively associated but also depended on the amount of spruce. Gender and age did not have an important influence on the amount and timing of sanitary felling. Forest owners are an important factor in effective bark beetle management. This study highlights the private forest ownership characteristics that should be emphasized in order to fight bark beetle outbreaks in the event of large-scale disturbances. Governments should support forest owners who are at greater risk of bark beetle outbreaks and less efficient in managing outbreaks. Furthermore, landowner characteristics should be included when forecasting bark beetle outbreaks.
Keywords: close-to-nature management, sanitary felling, Ips typographus, forest pest management, forest owner characteristics
Published in DiRROS: 22.03.2021; Views: 1155; Downloads: 818
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Keywords: biological control, entomopathogenic fungi, rhizosphere competence, soil pest
Published in DiRROS: 19.05.2020; Views: 2297; Downloads: 1185
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