scholarly journals Grishchenko. Protection of Spruce Forests from Outbreaks of Ips typographus (Review)

Author(s):  
Nana Pirtskhalava-Karpova ◽  
◽  
Aleksandr Karpov ◽  
Evgeniy Kozlovski ◽  
Mikhail Grishchenko ◽  
...  

Outbreaks of Ips typographus (L.) caused by catastrophic natural phenomena in Central Europe, Siberia and the Far East have been the subject of numerous scientific studies. Molecular methods were used to analyze the relationships and origin of Ips species. The review article shows in detail the biological characteristics of I. typographus, such as the effect of temperature on vital parameters and flight behavior. It was found that the spruce bark beetle disperses within 500 m. However, new attacks occur in the immediate vicinity of the old foci. The susceptibility and protection mechanisms of trees are critical to a successful bark beetle attack. The newly attacked trees react with preformed resin, reactions to wounds, and, ultimately, systemic changes in physiology. The risk assessment in the studies was carried out both at the tree level and at the forest level as a whole. The risk of an attack of I. typographus is associated with the growth of the forest in a particular area, age, the flow of nutrients and water to the tree. The dynamics of outbreaks, to a large extent, depend on the abundance of I. typographus, susceptibility of trees, weather conditions and phytosanitary measures. Bark beetle I. typographus is an integral component of any forest ecosystem. It colonizes weakened, weak or dead trees, and thus begins the decomposition of bark and wood. This pest is able to use short-lived resources and quickly multiply to extremely large numbers, for example, after winds. In such epidemic situations, I. typographus can pose a serious threat to spruce-rich forests, especially for stands planted outside their optimal range. The spatial development of I. typographus infections can be analyzed using GIS and multiple regression methods to investigate potential correlations between climatic, specific and phytosanitary factors and infection dynamics. Also, the article discusses various methods of forest control and emphasizes the need for more sophisticated risk assessment tools.

2003 ◽  
Vol 154 (11) ◽  
pp. 437-441 ◽  
Author(s):  
Franz Meier ◽  
Rolf Gall ◽  
Beat Forster

In the past 20 years, several mass attacks by the eight-toothed spruce bark beetle (Ips typographus L.) occurred in Switzerland. Since 1984 data on compulsory fellings, numbers of infestation spots and numbers of beetles captured in pheromone traps have been collected in all Swiss forest districts. The annual data were published in short reports. This paper gives an overview of the progress of bark beetle epidemics from 1984 to 1999. On the national level, two periods with epidemics of the spruce bark beetle can be distinguished. The first epidemic started after windthrows and drought in the years 1982 and 1983. It reached its height in 1984/1985 and faded at the end of the decade. The second epidemic started after the storm Vivian (February 1990). It reached its height in 1992/1993 and ended in 1997. Storm damage that produced high quantities of suitable breeding material was not the only factor for the bark beetle gradation;weather conditions were also exceptional, such as hot and dry vegetation periods. Windthrows and exceptional weather conditions are mostly events on regional scales and do not affect the whole country with the same intensity. The gradation that appears to be an «epidemic of the spruce bark beetle in Switzerland after the storm Vivian» is in truth the accumulation of several local epidemics. This is shown by the number of compulsory fellings and infestation spots analysed at regional levels. Extreme weather conditions and storms not only directly influence the bark beetle population, they also stress standing trees, thus creating suitable breeding material for bark beetles. To analyse the influence of exceptional weather conditions on bark beetle epidemics,it is therefore necessary to evaluate regional data.


Author(s):  
Rikito Hisamatsu ◽  
Rikito Hisamatsu ◽  
Kei Horie ◽  
Kei Horie

Container yards tend to be located along waterfronts that are exposed to high risk of storm surges. However, risk assessment tools such as vulnerability functions and risk maps for containers have not been sufficiently developed. In addition, damage due to storm surges is expected to increase owing to global warming. This paper aims to assess storm surge impact due to global warming for containers located at three major bays in Japan. First, we developed vulnerability functions for containers against storm surges using an engineering approach. Second, we simulated storm surges at three major bays using the SuWAT model and taking global warming into account. Finally, we developed storm surge risk maps for containers based on current and future situations using the vulnerability function and simulated inundation depth. As a result, we revealed the impact of global warming on storm surge risks for containers quantitatively.


2012 ◽  
Vol 61 (4) ◽  
pp. 662-663 ◽  
Author(s):  
Ian M. Thompson ◽  
Donna P. Ankerst

2021 ◽  
pp. 103985622098403
Author(s):  
Marianne Wyder ◽  
Manaan Kar Ray ◽  
Samara Russell ◽  
Kieran Kinsella ◽  
David Crompton ◽  
...  

Introduction: Risk assessment tools are routinely used to identify patients at high risk. There is increasing evidence that these tools may not be sufficiently accurate to determine the risk of suicide of people, particularly those being treated in community mental health settings. Methods: An outcome analysis for case serials of people who died by suicide between January 2014 and December 2016 and had contact with a public mental health service within 31 days prior to their death. Results: Of the 68 people who had contact, 70.5% had a formal risk assessment. Seventy-five per cent were classified as low risk of suicide. None were identified as being at high risk. While individual risk factors were identified, these did not allow to differentiate between patients classified as low or medium. Discussion: Risk categorisation contributes little to patient safety. Given the dynamic nature of suicide risk, a risk assessment should focus on modifiable risk factors and safety planning rather than risk prediction. Conclusion: The prediction value of suicide risk assessment tools is limited. The risk classifications of high, medium or low could become the basis of denying necessary treatment to many and delivering unnecessary treatment to some and should not be used for care allocation.


Author(s):  
Martin Schebeck ◽  
Nina Dobart ◽  
Gregory J. Ragland ◽  
Axel Schopf ◽  
Christian Stauffer

AbstractThe bark beetle Ips typographus is the most destructive insect pest in Norway spruce-dominated forests. Its potential to establish multiple generations per year (multivoltinism) is one major trait that makes this beetle a severe pest. Ips typographus enters diapause to adjust its life cycle to seasonally changing environments. Diapause is characterized by developmental and reproductive arrest; it prolongs generation time and thus affects voltinism. In I. typographus a facultative, photoperiod-regulated diapause in the adult stage has been described. In addition, the presence of an obligate, photoperiod-independent, diapause has been hypothesized. The diapause phenotype has important implications for I. typographus voltinism, as populations with obligate diapausing individuals would be univoltine. To test for the presence of different I. typographus diapause phenotypes, we exposed Central and Northern European individuals to a set of photoperiodic treatments. We used two ovarian traits (egg number and vitellarium size) that are associated with gonad development, to infer reproductive arrest and thus diapause. We found a distinct effect of photoperiod on ovarian development, with variable responses in Central and Northern European beetles. We observed obligate diapausing (independent of photoperiod) individuals in Northern Europe, and both facultative (photoperiod-regulated) as well as obligate diapausing individuals in Central Europe. Our results show within-species variation for diapause induction, an adaptation to match life cycles with seasonally fluctuating environmental conditions. As the diapause phenotype affects the potential number of generations per season, our data are the basis for assessing the risk of outbreaks of this destructive bark beetle.


Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1290
Author(s):  
Branislav Hroššo ◽  
Pavel Mezei ◽  
Mária Potterf ◽  
Andrej Majdák ◽  
Miroslav Blaženec ◽  
...  

Research Highlights: Bark beetles are important agents of disturbance regimes in temperate forests, and specifically in a connected wind-bark beetle disturbance system. Large-scale windthrows trigger population growth of the European spruce bark beetle (Ips typographus L.) from endemic to epidemic levels, thereby allowing the killing of Norway spruce trees over several consecutive years. Background and Objectives: There is a lack of evidence to differentiate how outbreaks are promoted by the effects of environmental variables versus beetle preferences of trees from endemic to outbreak. However, little is known about how individual downed-tree characteristics and local conditions such as tree orientation and solar radiation affect beetle colonization of downed trees. Materials and Methods: To answer this question, we investigated the infestation rates and determined tree death categories (uprooted, broken, and stump) in wind-damaged areas in Western Tatra Mts. in Carpathians (Slovakia) from 2014–2016, following a windthrow in May 2014. In total, we investigated 225 trees over eight transects. For every tree, we measured its morphological (tree height, crown characteristics), environmental (solar radiation, terrain conditions, trunk zenith), temporal (time since wind damage), and beetle infestation (presence, location of attack, bark desiccation) parameters. We applied Generalized Additive Mixed Models (GAMM) to unravel the main drivers of I. typographus infestations. Results: Over the first year, beetles preferred to attack broken trees and sun-exposed trunk sides over uprooted trees; the infestation on shaded sides started in the second year along with the infestation of uprooted trees with lower desiccation rates. We found that time since wind damage, stem length, and incident solar radiation increased the probability of beetle infestation, although both solar radiation and trunk zenith exhibited nonlinear variability. Our novel variable trunk zenith appeared to be an important predictor of bark beetle infestation probability. We conclude that trunk zenith as a simple measure defining the position of downed trees over the terrain can anticipate beetle infestation. Conclusions: Our findings contribute to understanding of the bark beetle’s preferences to colonize windthrown trees in the initial years after the primary wind damage. Further, our findings can help to identify trees that are most susceptible to beetle infestation and to prioritize management actions to control beetle population while maintaining biodiversity.


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