Short-term forecasting of bark beetle outbreaks on two economically important conifer tree speciesMaarten De Groot
, Nikica Ogris
Abstract: In recent years bark beetles have been shown to be an important risk factor in European forests. An early warning system is needed to mitigate bark beetle damage, and short-term forecasting models that assist efforts to identify attacked trees comprise an important part of such a system. The aim of this study was to develop short-term forecasting models of the probability of bark beetle outbreaks on two important conifer tree species: Norway spruce (Picea abies) and silver fir (Abies alba). For the development of the models, we used a time series of 20%years of sanitary felling because of bark beetles and relief data (altitude, slope and exposition), several soil variables, climate data (temperature and SPI), sanitary felling because of bark beetles, sanitary felling due to harmful abiotic factors, and amount of weakened trees due to bark beetles. The forecasting variable was sanitary felling because of bark beetles in the current year. The models were developed with a general linear model with binomial error distribution. For the probability of bark beetle outbreaks on silver fir, the amount of fir, soil base saturation percentage, sanitary felling of attacked fir, weakened fir, and sanitary felling because of abiotic factors increased the probability of sanitary felling because of fir bark beetles. Altitude, exposition, slope, phosphorus, soil depth, soil cation exchange capacity, SPI and temperature decreased the probability of sanitary felling because of fir bark beetles. For Norway spruce, the amount of Norway spruce, soil base saturation percentage, SPI, temperature, amount of sanitary felling in the previous year, amount of weakened trees in the previous year, and amount of sanitary felling because of abiotic factors in the previous year increased the probability of sanitary felling of Norway spruce because of bark beetles in the current year. Slope, soil cation exchange capacity, and precipitation decreased the probability of sanitary felling because of bark beetles in the current year. The performance of the bark beetle risk model for Norway spruce was very good. The performance of the model for silver fir was also good, but not on par with that for Norway spruce. Therefore, additional research on fir bark beetles is needed to further improve the risk model for bark beetle attacks on silver fir.
Keywords: Picea abies, Abies alba, Ips typographus, Fir bark beetles, European spruce bark beetle, forest protection, modeling
DiRROS - Published: 20.02.2020; Views: 106; Downloads: 71
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The first record of two non-native ambrosia beetles in Slovenia: Ambrosiodmus rubricollis (Eichhoff, 1875) and Ambrosiophilus atratus (Eichhoff, 1875) (Coleoptera: Curculionidae, Scolytinae)Tine Hauptman
, Barbara Piškur
, Massimo Faccoli
, Blaž Rekanje
, Andraž Marinč
, Maja Jurc
Abstract: In September 2017, during the monitoring of the non-native ambrosia beetle Xylosandrus germanus (Blandford, 1894), one specimen of an unknown ambrosia bark beetle species was collected in Slovenia. The specimen was trapped in an ethanol-baited trap located in Klavže (46 09 39 N, 13 48 7 E), in the western part of Slovenia. The most characteristic feature distinguishing the specimen from other known ambrosia beetle species occurring in Slovenia was the asperities that covered the entire surface of the pronotum. Based on the scientific literature concerning the non-native bark and ambrosia beetles in Europe (Kirkendall & Faccoli 2010) and illustrated identification keys (Rabaglia et al. 2006; Faccoli et al. 2009), we identified the beetle by its morphological characteristics as Ambrosiodmus rubricollis (Eichhoff, 1875). As a result of this find, a specific monitoring was set up in 2018 in Slovenia with the aim to improve the knowledge about occurrence and distribution of A. rubricollis in this country.
Keywords: Coleoptera, Curculionidae, Scolytinae, forest health, alien species, ambrosia bark beetles, first record, Ambrosiodmus rubricollis, Ambrosiophilus atratus, Slovenia
DiRROS - Published: 20.02.2020; Views: 93; Downloads: 94
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First record of the Asian ambrosia beetle, Xylosandrus crassiusculus (Motschulsky) (Coleoptera: Curculionidae, Scolytinae), in SloveniaAndreja Kavčič
Abstract: Xylosandrus crassiusculus (Coleoptera: Curculionidae, Scolytinae), with the common name the Asian ambrosia beetle or the granulate ambrosia beetle, originates in tropical and subtropical regions of eastern Asia. It is one of the most widespread wood-boring beetles and among these one of the most successful invaders (IPPC 2017). Outside its native habitat, the species is present in Africa (Wood & Bright 1992, Atkinson et al. 2000), in Australia (IPPC 2017), on the Pacific Islands (Beaver 1976), in the Americas (Atkinson 1988, Rabaglia et al. 2006, Flechtmann & Atkinson 2016, Landi et al. 2017) and in Europe (Pennacchio et al. 2003, Nageleisen et al. 2015, Gallego et al. 2016, Francardi et al. 2017).
Keywords: alien invasive species, bark beetles, polyphagy, broad-leaved woody plants, natural dispersal, impact
DiRROS - Published: 20.02.2020; Views: 115; Downloads: 97
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