Pine wilt nematode, Bursaphelenchus xylophilus, is quarantine harmful organism which causes pine wilting. In case of favorable environmental conditions fast reproduction of this nematode could cause fast decline of host tree species – especially from genera Pinus or rarely from Picea, Abies or Larix. Infestation of certain habitats is conditioned by susceptible host plants, environmental factors and vector presence. The most important factor governing pine wilting is temperature threshold of 20 °C during the summer. Extent and speed of host plant decline is also influenced by drought stress. If monthly average temperature during the summer does not rich the threshold, the development of pine wilt nematode is obstructed and latent infection takes place. However, during latent phase detection of infection become difficult due to absence of visible symptoms. Simulation of natural spread of pine wilt nematode was modelled from three entry points. Spatial data of temperature was classified in four classes. Areas with summer temperature lower than 18 °C was considered as not favorable for pine wilt nematode development. However, areas with higher temperature were classified in three classes corresponding to its influence on development of pine wilt nematode. Due to detailed map of average monthly temperatures in a period 1971–2000 new maps of climatic changes were constructed by spatial interpolation. New maps of each element of water balance were built in order to define drought stress condition in host plants. For monitoring purposes areas of risk categorization for introduction and spread were also determined based on different factors.
F.02 Acquisition of new scientific knowledge
COBISS.SI-ID: 5008744Personal view on the implementation of the activities of those who are responsible for the strategies and actions in relation to alien organisms1 is presented. In addition, there is a vast area that concerns the professional and the general public, its information and encouragement to participate. Listed are the main highlights to reflect on possible solutions which relate primarily to the spread of invasive alien species, therefore the most dangerous pests and diseases of forests and woody plants. This paper is a contribution to pose questions: How, then, in the future to act, what can we do, or even is there anything to do?
F.24 Improvements to existing system-wide, normative and programme solutions, and methods
COBISS.SI-ID: 4362150Ash dieback is a fungal disease caused by invasive alien fungus Hymenoscyphus fraxineus. Pathogen was most likely introduced into Europe from Asia and represents a serious threat to the common ash (Fraxinus excelsior) and narrow-leaved ash (F. angustifolia) populations. In Slovenia, the symptoms of ash dieback were first observed in 2006 in Prekmurje. Over the next 2 years, the disease expanded throughout the country. In 2011, research plots for monitoring of ash dieback were set at nine locations in Slovenia. The first damage assessment was carried out in August 2011 and the second in August 2014. Mean dead crown share was in 2011 estimated to 15.5 %, and in 2014, this estimate increased to 33.9 %. Mortality increased from 2.2 % in 2011 to 7.7 % in 2014. Fungi from the genus Armillaria are importantly involved in the ash decline process. Share of Armillaria infected ash trees increased from 9.6 % in 2011 to 52.1 % in 2014. These assessments showed that the ash stands are already heavily damaged in Slovenia and that the deterioration of ash health is progressing rapidly. Significant reduction in European ash populations is expected. Individual resistance of ash trees, found also in our research, is crucial for the existence of ash in our forests.
F.27 Contribution to preserving/protecting natural and cultural heritage
COBISS.SI-ID: 4370086In the last decades in Slovenia numerous extreme weather phenomena take place; among them, the worst dimensions and consequences had the hundred year drought in 2003 and icestorm (sleet) in February 2014. The climatologists forecast droughts and major disasters also for the future. They will cause major mechanical and physiological damage of forest trees. Above all in the lowland stand of the Norway spruce (Picea abies) we can also expect major damages due to biotic factors, e.g. Ips typographus, Pityogenes chalcographus and other bark beetles, native phytoparasites and invasive non-native harmful organisms. In the field of integrated forest protection (IFP) we stand in front of new professional challenges of the application of new knowledge on abiotic and biotic forest damages in Slovenia and abroad, fast changes of weather conditions in environment, and increasing entry of non-native harmful species into the forests. These facts require development and application of modern IFP strategies (MSIFP). In this article we deal with an important segment of IFP: adequacy of diverse biotechnical methods and chemical agent application for bark beetle control. Bark beetles infestation requires performing all integrated forest protection actions. Preferentially and all year round sanitation felling of the bark beetle infested spruce trees and removal of infested trees from the forest, followed by destruction of bark beetles. Extremely important is timeliness of performance of these actions; it must take place before flying out of a new beetle generation, which requires appropriate technical support, coordination, and good organization of all actors of these actions. As an additional action for bark beetle damage reduction it makes sense to increase the number of pheromone traps and "trap trees" in form of fallen trees, trunks and piles (with the thicker parts of branches on the outside of the pile) in the most endangered areas. Traps and "trap trees" could be also used as bark beetle control, but only in certain conditions. As we catch only a part of swarming beetle populations in pheromone traps and "trap trees", we cannot stop escalation of bark beetles only with these actions. Use of insecticides in Slovenia is limited by the Forest Act (1993), use of dangerous insecticides is also forbidden in FSC certified forests. Use of attested insecticides can be reasonably performed only in a limited scope for the immobilization of the infested forest wood assortments, which cannot be transported from forest before the flying out of a new beetle generation. Use of insecticide nets (for example systems Trinet(R) and Storanet(R)) is due to their negative impact on forest ecosystem not justifiable
F.14 Improvements to existing production methods and tools or processes
COBISS.SI-ID: 4711590Tree diseases and pests have huge impact on the forest ecosystem health at all development stages. In this paper we mention some of the most common and important diseases and pests in terms of renewal, rejuvenation of forests. We emphasize that it is necessary to: (1) improve the whole chain from seed to viable plants in the woods; (2) In addition to providing healthy seedlings assure a system that will provide quality seedlings, a standard or quality manual, which will define the required morphological characteristics of quality seedlings, the method of excavation, transport, manipulation of seedlings before planting, methods of planting and care after planting, on which the success of artificial reforestation with planting depends; (3) Provide regular tests for the presence of hidden, latent, and cryptic pests, with emphasis on the genus Phytophthora in forest nurseries.
F.18 Transfer of new know-how to direct users (seminars, fora, conferences)
COBISS.SI-ID: 4773286