prilagođeno pretraživanje po punom tekstu

ŠUMARSKI LIST 1-2/2019 str. 24     <-- 24 -->        PDF

elevation and season. At higher elevations, sanitation measures aimed at reduction of the emergence of new infestation spots (Stadelmann et al., 2013) need to be implemented in early autumn when most of the beetles are still under the bark while in lowlands, felling in early spring or late autumn can achieved high efficiency. Winter felling does not only kill most bark beetles within bivoltine populations, but also eliminates a huge fraction of their natural enemies whereas with univoltine populations of this pest, this is much less detrimental (Wermelinger et al., 2012). In regions with beetle outbreaks, the priority need to be salvage logging of damaged timber, particularly in years affected by storm events (Stadelmann et al., 2013). Salvage logging should be followed by sanitation felling which ought to comprise the area within 100 m from previous infestations (Kautz et al., 2013). The removal of attacked standing trees may additionally cause edge effect in subsequent spring (Dworschak et al., 2014) when colonized wind felled trees (Esseen, 1994; Peltonen, 1999) or killed standing trees (Hedgren, 2002) can be frequent occurrence due to the beetles that overwinter in the litter and constitute the local population within the spots of attacks.
Foresters need to consider the fact that bark falls off in upper parts of standing trees during the winter period (Dworschak et al., 2014) and changes the portion of beetles between niches. It could have a negative impact on the success of sanitation recovery planned for spring. Upper parts of standing trees are often heavily infested, which can modify insulator characteristics of the bark and result in peeling and higher winter mortality (Faccoli, 2002) as well as in a higher proportion of upper tree beetles which leave the bark during the winter (Komonen et al., 2011). During sanitation felling, the removal of attacked standing trees with needles discolouration need to be carried out first. For that purpose, individual inspection of symptoms (resin flow, boring dust around the trunk) in each tree is necessary. Sometimes it is difficult to conduct such an inspection due to a shortage of time and manpower. If beetles complete their development and leave trees, it might be good to leave those trees in stands for some time because the bark beetle antagonist can be removed with them (Wermelinger et al., 2012). The impact on the natural enemies can be minimized if heavy infested trees are removed out of stands before the emergence of bark beetles.
All the authors are grateful to Marko Kasumović, Milan Starčević, Mile Kasumović and Pere Kulaš for their generous support during the field work. Many valuable research-related data have been provided by Ivica Serdar, head of the Department of Forest Measurement in a state-owned company Croatian forest Ltd, who has made a priceless contribution to this study.
Annila E., 1969: Influence of temperature upon the development and voltinism of Ips typographus L. (Coleoptera: Scolytidae). Ann. Entomol. Fenn. 6: 161-208
Annila E., 1971: Sex ratio in Ips typographus L. (Coleoptera: Scolytidae). Entomol. Fennica 37:7-14
Andebrant O., 1986: A model for temperature and density dependent reemergence of the bark beetle Ips typographus. Entomol. Exp. Appl. 40:81-88
Austarå Ø., Pettersen H., Bakke A., 1977: Bivotinism in Ips typographus in Norway and winter mortality in second generation. Medd. Norweg. Inst. Skogforsk. 33: 269-281
Baier P., Pennerstorfer J., Schopf A., 2007: PHENIPS – A comprehensive phenology model of Ips typographus (L.) (Col., Scolytinae) as a tool for hazard rating of bark beetle infestation. Forest. Ecol. Manag. 249: 171-186. doi:10.1016/j.foreco.2007.05.020
Bakke A., Frøyen P., Skatebøl L., 1977: Field response to a new phermonal compound isolated from Ips typographus. Naturwissenschaften 64:98-99
Botterweg P. F., 1982: Dispersal and flight behaviour of the spruce bark beetle Ips typographus in relation to sex, size and fat–content. J. Appl. Entomol. 94:466-489. doi:10.1111/j.1439-0418.1982.tb02594.x
Byers J. A., 2012: Ecological Interactions of Bark Beetles with Host Trees. Psyche 2012:1-3. doi:10.1155/2012/252961
Christiansen E., Bakke A., 1997: Does drought really enhance Ips typographus epidemics? A Scandinavian perspective, Proceedings: Integrating cultural tactics into the management of bark beetles and reforestation pests, USDA Forest Service General Technical Report NE-236, p 163-171
10. Christiansen E., Bakke A., 1988: The spruce bark beetle of Eurasia, Dynamics of Forests Insect Populations. Patterns, Causes, Implications. Plenum Press, p 479-503, New York-London
Coeln M., Niu Y., Fuhrer E., 1996: Temperature-related Development of Spruce Bark Beetles in Montane Forests Formations (Coleoptera: Scolytidae). Entomol. Gen. 21:37-54
Doležal P., Husáková J., Sehnal F. 2009: Effect of temperature on the termination of imaginal diapause in the spruce bark beetle Ips typographus (L.) hibernating under the bark or in the litter. In: Kunca, A.; Zúbrik, M. (ed) Insects and Fungi in Storm Areas. Proceeding of the IUFRO WP 7.03.10: Methodology of Forest Insects and Disease Survey in Central Europe. Štrbské Pleso, Slovakia, p 50-55
Dworschak K., Meyer D., Gruppe A., Schopf R., 2014: Choice or constraint: Plasticity in overwintering sites of the European spruce bark beetle. Forest. Ecol. Manag. 328:20-25. doi:10.2016/j.foreco.2014.05.012
Esseen P. A. 1994: Tree mortality patterns after experimental fragmentation of an old-growth conifers forest. Biol Conserv 68, 19-28.
Faccoli M., 2002: Winter mortality in sub-corticolous populations of Ips typographus (Coleoptera: Scolytidae) and its parasitoids in the south-eastern Alps. J. Pest Sci. 75:62-68. doi:10.1034/j.1399-5488.2002.02017.x
Faccoli M., 2009: Effect of Weather on Ips typographus (Coleoptera, Curculionidae) Phenology, Voltinism and Associated