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Reverse engineering (RE) aims at the reproduction of products following a detailed examination of their construction or composition. Nowadays, industrial applications of RE were boosted by combining it with additive manufacturing. Printing of reverse-engineered elements has become an option particularly when spare parts are needed. In this paper, a case study was presented that explains how such an approach can be implemented in the case of products with asymmetric mechanical properties and using replacement materials. In this case study, a reverse engineering application was conducted on a textile machine spare part. To this end, the nearest material was selected to the actual material selection and some mechanical tests were made to validate it. Next, a replacement part was designed by following the asymmetric push-in pull-out characteristic. Finally, the finite element analysis with Additive Manufacturing was combined and validated experimentally. more...

Pheromone traps are used for monitoring I. typographus populations in Norway spruce stands of the Tatra National Park (TPN) in Poland. The presented study is based on the set of pheromone traps of precisely known location (23) located in the whole area of the TPN and operated continuously in 2010–2019. The data on the captures of beetles were compared with two kinds of data concerning the mortality: the area covered by standing dead trees (airborne photographs) in the no-intervention zone, and the volume of trees infested by bark beetles processed in the active protection zone. No relationship was found between the mean numbers of beetles captured yearly in all pheromone traps in the whole TPN area and the volume of infested trees removed from the stands in the active protection zone. The captures in the two selected study areas were correlated with the area of spots with dead trees in the 500 m circle around the traps, however, this correlation is not statistically significant. There is no relation of captures to the volume of processed infested trees. The captures decreased in the growing seasons after the wind damage, and increased markedly after the drought started in 2015. The results of pheromone trapping are affected by several factors, as wind damage and defence potential of trees resulting from their physiological status. Pheromone traps represent valuable source of information about the bark beetle I. typographus population dynamics, although the collected data do not enable direct definition of its population level, especially in the protected areas with different and unstable (changed in 2017) approach to the protection of stands. As most of the information on beetles is captured in the first half of the growing season, the data collected till the end of July are sufficient for monitoring purposes; thus, the trapping should be reduced to the period May–July. more...

Pine sawflies (Hymenoptera: Diprionidae) belong to the most common pests of Scots pine Pinus sylvestris L. in the area of the Regional Directorates of State Forests in Toruń and Gdańsk. The two most destructive species, Diprion pini L. in the area of Puszcza Bydgoska and Gilpinia virens (Klug) in Bory Tucholskie, were investigated in this study. Our main aim was to characterise the two species in the Bydgoszcz Forest District in RDSF in Toruń and Kaliska in RDSF in Gdańsk, respectively, based on data gathered during outbreaks between 1991 and 2011. For this purpose, a geometric database was created, containing information about the year of outbreak, number of larvae observed after tree felling as well as selected stand and site features including stand age and species composition, stocking index, canopy closure, site index, humidity and fertility. By analysing the occurrence of both species in relation to stand and site features, we were able to determine their environmental requirements, which are quite different from one another. D. pini preferred older stands, with a stocking index between 0.8–0.9, growing on fresh and dry coniferous sites, while species composition (share of pine), canopy closure or site index did not have any influence on its abundance. G. virens preferred middle-aged pure pine stands, with relatively open canopies, on fresh coniferous sites and poorer soils. The stocking index did not affect its occurrence. more...

In 2013–2014, a set of 30 pheromone traps baited with synthetic lures attracting I. duplicatus (Duplodor – 15 traps) and I. cembrae (Cembrodor – 15 traps) was installed in 6 altitudinal transects (1000–1400 m a.s.l., every 100 m of elevation) in the eastern, central and western part of the Tatra National Park (TPN) in Poland and operated during the entire growing season. The main aim of the survey was to check if and to what vertical extent these two species of bark beetles, not yet recorded, are presently distributed in TPN. Collected insects, including non-target Scolytinae and Cerambycidae, were determined. Overall 1896 Scolytid bark beetles belonging to 13 species, all occurring in the whole elevation range, were collected. I. duplicatus (28 specimens in total) was collected in the whole elevation profile, similarly as I. cembrae (718 specimens in total). Among Cerambycidae (282 individuals) belonging to 19 species, Rhagium inquisitor and Pidonia lurida, found on all elevations, were the most abundant; 8 species were collected on the highest locality. Pogonocherus decoratus was found for the first time in the Tatra. Results indicate the upward spreading of the studied insects as a possible effect of climate change and the resulting environmental conditions favourable for those organisms. more...

In March 2017, in the eastern part of the Tatra National Park in Poland, large windthrowns affected the passively and actively protected Norway spruce Picea abies stands. In early 2018, a set of 12 small research plots (20 trees on each plot) was established in the Norway spruce stands next to the windblown area – 6 in the stands under active nature protection (broken and fallen trees processed in 2017), and 6 in the stands under passive nature protection (trees left on the ground). Living trees on the plots were regularly checked during the growing season in order to identify and register the spruces infested by Ips typographus, which were dissected in 2 or 4 half-meter sections. 155 spruces (64%) infested by I. typographus were recorded on all 12 plots: 118 out of 120 (98%) in passive and 37 out of 120 trees (31%) in active protection. Mean infestation density calculated on 128 samples from 47 trees was higher under passive than under active protection (1.23 and 0.92 mating chamber per 1 dm2, respectively). Among 1709 gallery systems, those with 2 maternal galleries prevailed (63.0%); the mean share of females was higher in passive than in active protection zone (63.1 and 59.6% respectively). The mean number of progeny per one female was higher in active than in passive protection zone (20.23 and 19.12 respectively). I. typographus attack on standing trees had lower intensity in the stands previously subjected to the processing and removal of fallen and broken trees, which indicates positive effect of implemented active protection procedures. The parameters describing I. typographus population on attacked trees, as well as low activity of natural enemies, demonstrate its reproduction potential and resulting high risk of a new outbreak, according to the pattern known earlier from the other areas in Poland and Europe. more...

The low-cycle deformation of 304L austenitic stainless steel was examined in terms of energy conversion. Specimens were subjected to cyclic loading at the frequency of 2 Hz. The loading process was carried out in a hybrid strain–stress manner. In each cycle, the increase in elongation of the gauge part of the specimen was constant. During experimental procedures, infrared and visible-range images of strain and temperature fields were recorded simultaneously using infrared thermography (IR) and digital image correlation (DIC) systems. On the basis of the obtained test results, the energy storage rate, defined as the ratio of the stored energy increment to the plastic work increment, was calculated and expressed in reference to selected sections of the specimen. It was shown that, before the specimen fracture in a specific area, the energy storage rate is equal to zero (the material loses the ability to store energy), and the energy stored during the deformation process is released and dissipated as heat. Negative and close-to-zero values of the energy storage rate can be used as a plastic instability criterion on the macroscale. Thus, the loss of energy storage ability by a deformed material can be treated as an indicator of fatigue crack initiation. more...

At the end of 2013, strong wind destroyed spruce stands on large areas of Kościeliska Valley in Tatra Mts. in Poland. In 2015–2017, 304 bark samples were collected from 106 spruces; 25 cm × 25 cm large samples were taken from 2 or 4 sections of infested trees in July/August each year. The infestation density, sex ratio, length of maternal galleries, number of progeny and impact of natural enemies were recorded. The infestation density in individual years was 0.79–0.86 mating chambers per dm2, the average length of maternal gallery (55.2–56.6 mm) did not differ between years, The average number of progeny per female from 3-year pooled data was 18.22, the highest in 2015 (27.4) then collapsed to 15.5–16.8. The gallery systems with 2 females, in which the reproduction success was the highest, dominated (62.6%). The frequency of parasitoids or entomopathogens was very low (2–20% mortality rate in 19 bark samples). Possible reasons of relatively low reproduction success regardless generally favourable breeding conditions and its collapse after first year, such as high infestation density and low survival rate of larvae because of climatic conditions (drought), are discussed. Taking into account the described population features, very intense tree mortality and mechanisms known from the other wind events, further development of the outbreak can be expected in this area. more...

At the end of 2013, Norway spruce stands in the area of the Tatra National Park were severely damaged by strong storms especially in the Kościeliska Valley region. In the following spring of 2014, a survey recording the occurrence of the spruce bark beetle Ips typographus (Coleoptera, Curculionidae, Scolytinae) was initiated in order to describe the dynamics of beetle reproduction in relation to protection measures executed in wind-damaged stands. Ten research plots with 20 trees each were established in a socalled active protection zone, where the broken and fallen trees had been processed and removed in 2014, and in a passive protection zone, where no actions were taken, and the dynamics of Norway spruce mortality due to bark beetle infestation including quantitative parameters (infestation density, sex ratio of beetle populations) were examined. The entomological analyses were performed on 25 × 25 cm large bark samples taken from four (active zone) or two (passive zone) tree sections. In the first year of the survey, no infested standing trees were recorded on the plots and the colonisation of fallen and broken trees was very weak. In the second year (2015), infestations appeared in larger numbers on the plots with passive compared to active protection but the infestation density was 0.89 mating chambers per 1 dm2 regardless of the protection status. In the third year (2016), most of the remaining living spruces had been infested with a mean density of 0.82 m.ch. per 1 dm2. In 2015, the proportion of females in the beetle population was 65.8% being higher in the active (68.4%) than the passive (64.0%) protection zone, while in 2016 the proportion was 63.5% and in this case slightly higher in the passive protection zone (63.9% as compared to 63.2%). These results are in accordance with patterns observed in wind-damaged Norway spruce stands of other areas in Poland and Europe and demonstrate the usefulness of forest management procedures in mitigating I. typographus outbreaks. more...

Spruce bark beetle Ips typographus (L.) (Col.: Curculionidae, Scolytinae) outbreaks occur in managed and protected forests alike, but although known of for a long time, management and control of this insect is a controversial subject due to the forests’ diverse nature and protection status. In this paper, an overview of the bark beetle, conditions leading to outbreaks, natural enemies and the efficiency of control measures is presented and put into perspective with regards to the current controversies concerning outbreak management. The Białowieża Primeval Forest is central to this discussion, because the area remains divided into parts with different nature protection statuses. Ideas concerning the current but also future outbreak progress and possible issues with the management of natural resources in this area are presented. more...

Norway spruce trees weakened by soil drought and progressive die-off of mycorrhizas in root systems become susceptible to infection by rhizomorphs of Armillaria spp. The developing mycelium of this necrotroph induces resin channels in wood, and the induced resin releases some volatile compounds which falsely signal bark beetles that it is safe to invade the host. As a result of the developing beetle outbreak, host trees die, becoming a long-term stock of substrate for the fungus in its saprotrophic stage. This hypothesis is discussed as a fungal survival strategy. more...

Outbreaks of the European spruce bark beetle Ips typographus kill extensive areas of Norway spruce forests in Central Europe, affecting both protected areas and neighboring commercial forests. In protected areas, uncontrolled (non-intervention) management allows natural beetle-induced tree mortality, while in commercial forests infested trees are salvage-logged in order to lower I. typographus numbers and stabilize wood production. However, the effects of active pest controls on I. typographus population are often ambiguous, and little is known about how antagonists, beetle density, or intraspecific competition help terminate I. typographus outbreaks. To answer this question, we studied I. typographus population development, breeding performance, and natural antagonists under intervention and non-intervention management in the High Tatra Mts. from 2014 to 2017. We used sentinel logs and windthrown trees, following the current legislation in Tatranský narodný park (TANAP, Slovakia) and Tatrzanski Park Narodowy (TPN, Poland). Both parks are mountainous, are covered by Norway spruce forests that have been extensively affected by windthrows and extensive I. typographus outbreaks over the last 20 years, and are zoned under intervention and non-intervention types of management. We found that I. typographus was a dominant species and that its numbers gradually increased during the study, but that the numbers of maternal galleries in sentinel logs (from 50 to 300 per m2) and sex ratio (1 male:2.5 females) remained the same among years. The length of maternal galleries and egg production (per m2 of bark), however, gradually declined, and breeding performance decreased from 10 daughter beetles per female in 2014 to almost zero in 2017. These parameters did not significantly differ between intervention and non-intervention sites. Antagonists were not abundant and had limited effects on I. typographus numbers. Active intervention did not affect I. typographus population dynamics or rates of parasitism but increased numbers of Thanasimus beetles, which are predators of bark beetles. In other words, intervention increased the numbers of some natural enemies of I. typographus but did not affect I. typographus population dynamics. Because control measures did not reduce I. typographus numbers in the intervention zone, the natural ecological processes crucial for maintaining ecosystem functioning and biodiversity were evidently preserved. more...

The study estimated the efficacy of a net coated with alpha-cypermethrin used to protect Norway spruce [Picea abies (L.) H. Karst] wood against bark beetle infestations. The inside of the net was coated with 100 mg/m2 of alpha-cypermethrin. The studies carried out in 2010 and 2011 took place in southern Poland in the Beskid Żywiecki and Beskid Sądecki mountains in P. abies stands threatened by Ips typographus (Linnaeus, 1758). The research material consisted of wood logs taken off of 70–80-year-old P. abies trees. The logs were wrapped in the net in the early spring before spring swarming of bark beetles. The unwrapped logs were considered as the study controls. An evaluation of the treatments was performed after 2 months. The evaluation was based on the counting of bark beetles galleries found after removing the bark from the wrapped and unwrapped logs. There were no insect galleries on the wrapped logs. The net was a barrier, on which bark beetles died. About 10 dead I. typographus beetles were found on 0.01 m2 of the net surface. On the bark from the unwrapped-control logs there were 3,156 galleries/entrance holes of bark beetles, in total, of which 73% belonged to I. typographus, 13% to Pityogenes chalcographus (Linnaeus, 1761), and almost 10% to Xyloterus lineatus (Oliv.). These results indicated the high efficacy of the net coated with alpha-cypermethrin used for the protection of Norway spruce wood against the bark beetles. At the same time, the net was found to have a negative effect on non-target entomofauna, mainly Hylobius spp., Thanasimus formicarius (L.), and Tetropium castaneum (F.). However, the use of a net did not affect other predatory (Carabidae) and parasitic (Ichneumonidae and Tachinidae) entomofauna. more...

International audience; AbstractKey messageUnder an outbreak scenario in a buffer zone of a protected area, bark beetle-caused tree mortality was modulated by earlier natural disturbances (wind and bark beetles), sanitary management and seasonal temperature. In buffer zones, the effects of sanitary management on tree mortality remained limited due to the migration of bark beetles from unmanaged areas.ContextThe European spruce bark beetle (Ips typographus L.) is regarded as an economically significant pest of Norway spruce (Picea abies [L.] Karst). However, in protected areas, it is regarded as a keystone species for biodiversity. This results in two contrasting management strategies that meet in buffer zones of protected areas.AimsTo assess which environmental and management variables are most important for tree mortality in an ongoing bark beetle outbreak and to gain a better understanding of the challenges and recommendations for buffer zone management under the influence of nearby unmanaged stands in a protected area.MethodsNorway spruce tree mortality was assessed in 419 forest stands in the High Tatra Mountains. To account for spatial and temporal autocorrelations, generalized additive mixed models (GAMM) were used, and an information-theory (I-T) approach was adopted for model selection to test the influence of environmental variables, natural disturbances and the previous year’s sanitary cutting on bark beetle-caused tree mortality.ResultsIn buffer zones, P. abies tree mortality caused by I. typographus was positively correlated to natural disturbances and sanitary cutting in the previous year.ConclusionThe previous year’s sanitary cutting, maximum temperature sums, wind disturbance and trees left in no-intervention stands contributed to tree mortality in buffer zones. In these zones, the decrease of tree mortality in response to sanitary management remained limited due to the migration of bark beetles from unmanaged areas. However, sanitary management in buffer zones remains necessary for the isolation of bark beetle outbreaks in unmanaged areas. more...

To better understand the initiation and severity of tree mortality caused by the spruce bark beetle (Ips typographus (L.)) during an outbreak, we analysed the entire course of an outbreak from 1990 to 2000 in the Tatra Mountains (Western Carpathians, Central Europe). This time period represents the last complete bark beetle gradation in this area. We distinguished three outbreak phases: the incipient epidemic, epidemic and post-epidemic stages. The sampling unit was the forest subcompartment. We analysed a total of 315 forest subcompartments over more than 2000 ha. We investigated the influence of 11 environmental and stand variables on two processes in different phases of the outbreak: the initiation and the severity of spruce mortality. We used factor analysis, discriminant analysis, multiple linear regressions and boosted regression trees for the statistical analyses. The results showed that the roles of host and site factors in the initiation and severity of spruce mortality caused by the spruce bark beetle differed during the outbreak according to the exploitation of available host resources. The initiation of tree mortality was primarily related to host factors, and the severity of mortality was dependent on host size and insolation. more...

Kosibowicz M., Grodzki W., Jachym M. 2014: Local outbreak of the spruce needle tortricid Epinotia tedella Clerk (Lepidoptera, Tortricidae) in the Sudetes in Poland. – Beskydy, 7 (1): 29–38 In 2004–2006 a local outbreak of Epinotia tedella was recorded on an area of 1,371 ha in Middle and Eastern Sudetes (Sowie and Bialskie Mts.) in Poland. In Bialskie Mts. slight damage dominated, while in Sowie Mts. more concentrated but moderate damage prevailed. The damage on older trees was limited to the lower half of the crowns, while on younger trees the middle parts of the crowns were more affected. The results of one-year field experiments towards the development of monitoring and forecast tools are presented in the paper. The results from ground emergence traps reflected phenology of butterflies’ emergence and the species preferences regarding older stands. The pheromone traps demonstrated the insect concentration on higher (above 900 m a.s.l.) elevations and confirmed the preference of older stands. Field observations revealed that a part of caterpillars can overwinter in the feeding places in tree crowns. The outbreak was incidental, with no effect on trees and stands. No new damage was recorded after 2006. The use of emergence traps and pheromone traps can be an interesting perspective, but further experiments concerning the interpretation of results are needed. more...

An outbreak of spruce bark beetle (Ips typographus [L.]) in the Tatra Mountains in the Slovak Republic and Poland, Central Europe, was analysed. The study area was nearly 3000 ha. The 11 year outbreak lasted from 1990 to 2000. Three outbreak phases were identified: 1990–1994 (incipient epidemic), 1995–1996 (epidemic) and 1997–2000 (post-epidemic). More than 118,000 m3 of trees were damaged by wind and bark beetles. The analysis considered the relationship and succession of these two types of disturbances. Discrimination analysis, a multiple linear regression and boosted regression trees were used to determine the influence of 11 variables on tree mortality initiation and severity. The wind–bark beetles disturbance system was primarily influenced by stand related factors. Tree mortality initiation primarily depends on stand age and related changes in Norway spruce size and vitality. Wind caused tree mortality severity was primarily related to the tree or stand characteristics as well. The roles of host and environmental factors in the initiation and severity of tree mortality were influenced by the I. typographus outbreak phase. Stand, site and solar radiation variables were the most important factors impacting tree mortality severity caused by this disturbance system, especially in the epidemic phase. However, the severity of tree mortality caused by wind was primarily correlated with the stand characteristics. With the exception of elevation, the roles of the studied factors were similar in all gradation phases. more...

Forest biomass is a major store of carbon and thus plays an important role in the regional and global carbon cycle. Accurate forest carbon sequestration assessment requires estimation of both forest biomass and forest biomass dynamics over time. Forest dynamics are characterized by disturbances and recovery, key processes affecting site productivity and the forest carbon cycle. Thus, spatially and temporally explicit knowledge of these processes and their drivers are critical for understanding regional carbon cycles. Here, we present a new method that uses satellite data to estimate changes in forest aboveground biomass associated with forest disturbances and recovery at annual time steps. First, yearly maps of aboveground biomass between 1985 and 2010 based on Landsat time series and field data were created. Then, we applied a trajectory-based segmentation and fitting algorithm to the yearly biomass maps to reconstruct the forest disturbance and recovery history over the last 25 years. We tested the method over a coniferous forest region in the Western Carpathian Mountains, which experienced long-term environmental changes. Overall, 55% (~ 30,700 ha) of the total coniferous forest experienced a loss of biomass over the observation period, while ~ 30% showed severe or complete removal of forest biomass. At the same time, 11.2% of the area was reforested or regenerated on previously damaged forest stands. The total coniferous biomass dropped by 15% between 1985 and 2010, indicating negative balance between the losses and the gains. Disturbance hotspots indicate high insect infestation levels in many areas and reveal strong interactions between biomass loss and climate conditions. Our study demonstrates how spatial and temporal estimates of biomass help to understand regional forest dynamics and derive degradation trends in regard to regional climate change. more...

This paper considers the doubly periodic problem of elasticity for anisotropic solids containing regular sets of thin branched inclusions. A coupling principle for continua of different dimension is utilized for modeling of thin inhomogeneities and the boundary element technique is adopted for numerical solution of the problem. The branches of the inclusion can interact both inside the representative volume element and at the interface of neighbor representative elements. A particular example of the elastic medium reinforced by a doubly periodic set of I-beams is considered. Stress intensity and stress concentration inside and outside thin inclusions are determined. The dependence of the effective mechanical properties of the reinforced composite material on the volume fraction of the filament and its rigidity is obtained. more...

The objective of the current study was to identify pathogens of the large larch bark beetle, Ips cembrae, which is a secondary pest that has produced several local outbreaks across Europe in recent years. Beetles were collected from pheromone traps, trap trees and emergence traps (Larix decidua) during 2007 to 2011 at 10 study sites in central Europe. A total of 3379 mature and callow beetles were examined with a light microscope, and only two microsporidian pathogens [Chytridiopsis typographi and a diplokaryotic microsporidium (probably Nosema sp.)] and two gregarines (Gregarina typographi and Mattesia schwenkei) were found. Within the I. cembrae populations, the infection rate for C. typographi ranged from 2 to 58%. Nosema sp. occurred in only two beetles in 2007 (at two study sites). G. typographi was recorded only in Austria and Croatia and only in 1–2% of the beetles in those countries. Mattesia schwenkei was observed solely in Croatia in 0.6% of the beetles in that country. Only one fungal pathogen in the genus Fusarium was found and only in two mature beetles (0.7%) in 2010. The pathogen species found during our study of I. cembrae were very similar to the pathogens previously identified for Ips typographus. No species-specific pathogen was detected. more...

The current nature of forest management in Poland reflects its history and more than 100 years of economic activity affecting forests since independence in 1918. Before that time, different forest management models were used, related to the nature of the Prussian economy in the north of the country, the Russian economy in the central-eastern part, and the Austrian economy in south-eastern Poland. The consequence of these management models, as well as the differing climate zones in which they were used, resulted in varied forest health. Since the end of World War II, forest coverage within Poland‘s new borders has increased from 20.8% to currently 29.6%, mainly as a result of afforestation of wastelands and former agricultural lands. This paper describes changes in the health of forests and their biological diversity in Poland in the context of weather extremes, species composition, forest management, the forest industry, and damage from insects and pathogenic fungi over the last 30 years. more...

During 2006–2008 an increase in the occurrence of Ips cembrae was recorded in old stands of southern Poland, mostly in the area of Regional Directorates of State Forests in Katowice and Wroc3aw, where the volume of infested trees removed from the stands increased in 2007 by almost 7 times compared to 2006. Stands with a high proportion of larch as well as the younger and youngest ones (up to 60 years) were more infested thanmixed ones; larch growing on poor and humid sites was less susceptible to the infestations than on rich and dry ones. Intensive infestations were also recorded in young larch stands in two regions of southern Poland: in the Sudeten mountains at altitudes of 700–1100 m a.s.l. and in Silesia (~200 m a.s.l.), in areas reforested 15–20 years ago. The bark beetles infested 11% of young trees felled during thinning; maximum frequency was 56,5%. An origin of this outbreak was thinning without tree removal, which created favourable breeding conditions for the bark beetle. An area of potentially threatened young stands was estimated to about 10,5 thousand ha, and the damage caused by I. cembrae in such young stands generated a new problem for forest protection. more...

The distribution of the double spined spruce engraver beetle Ips duplicatus ranges from Scandinavia and northeastern Europe to northern Asia. In Europe, I. duplicatus usually is associated with I. typographus on Picea abies, and due to morphological similarities and similar gallery constructions the damage and significance of I. duplicatus are often not recognised and thus underestimated. I. duplicatus has been recently reported from the southern part of Poland, the Czech Republic, Slovakia, northern parts of Austria and Germany; records are missing from many other central European countries (e.g., Hungary). The species became an important pest in some parts of central Europe, and continuous outbreaks of this bark beetle have been reported in Inner Mongolia, China, since the 1950s. The aim of this study was to compare I. duplicatus populations from Europe and Asia by genetic means using the analysis of the mitochondrial DNA. Individuals of I. duplicatus populations from China, Poland, the Czech Republic and Slovakia were collected, and 520 bp fragments of the cytochrome oxidase I (COI) gene were analysed. Four haplotypes were detected and a sequence divergence of 0.8% was found between the populations from China and Europe. These differences associate with behavioural differences in the pheromone bouquet and behavioural response of the two groups. Within Europe three haplotypes were found, but due to the small sample size no significant geographical distribution was demonstrated. more...

Une pullulation massive de scolytes s'est deroulee entre 1993 et 1998 dans les montagnes Tatras, situees entre la Pologne et la Slovaquie. Dans la partie Slovaque de la surface attaquee, la pratique forestiere a consiste a ne pas intervenir jusqu'en 1994, puis en une protection active via l'utilisation d'arbres-pieges, d'insecticides et de coupes sanitaires entre 1995 et 1996, et en diverses techniques de lutte diversifiees selon la zonation des surfaces attaques, combinees a l'utilisation de piegeages a pheromones en 1997 et 1998. En Pologne la pullulation etait localisee en grande majorite dans des reserves strictes ou aucune mesure de protection n'etait autorisee. Malgre l'importance des moyens de lutte mis en oeuvre, la mortalite des arbres n'a pas diminue significativement dans la partie Slovaque pendant les annees 1995-1996. Les techniques utilisees aboutissaient a l'augmentation de l'attractivite des bordures de la foret pour les scolytes, et ceux-ci pouvaient s'y developper en provenance de zones forestieres ou le meme niveau de controle n'etait pas applique. Un climat defavorable au developpement des scolytes a largement contribue a la diminution rapide des mortalites d'arbres observees dans les deux parties de la region etudiee. more...

The spruce bark beetle, Ips typographus (L.) is the most serious pest of mature spruce stands, mainly Norway spruce, Picea abies (L.) Karst. throughout Eurasia. A complex of weather-related events and other environmental stresses are reported to predispose spruce stands to bark beetle attack and subsequent tree mortality; however the possible role of industrial pollution as a predisposing factor to attack by this species is poorly understood. The abundance and dynamics of I. typographus populations was evaluated in 60-80 year old Norway spruce stands occurring on 10 x 50 ha sites in five countries within the Carpathian range that were selected in proximity to established ozone measurement sites. Data were recorded on several parameters including the volume of infested trees, captures of adult beetles in pheromone traps, number of attacks, and the presence and relative abundance of associated bark beetle species. In several cases, stands adjacent to sites with higher ozone values were associated with higher bark beetle populations. The volume of sanitary cuttings, a reflection of tree mortality, and the mean daily capture of beetles in pheromone traps were significantly higher at sites where the O(3) level was higher. However, the mean infestation density on trees was higher in plots associated with lower O(3) levels. Captures of beetles in pheromone traps and infestation densities were higher in the zone above 800 m. However, none of the relationships was conclusive, suggesting that spruce bark beetle dynamics are driven by a complex interaction of biotic and abiotic factors and not by a single parameter such as air pollution. more...

Investigations on I. typographus populations were conducted in 1992–1994 in the Sudeten (south-western Poland), in Norway spruce stands that were devastated previously by insect outbreaks and that exhibited severe forest decline. Crown defoliation and the volume of infested trees per hectare were used as indices of stand health and breeding conditions; variability in the infestation density, gallery length, and body length of beetles were parameters that were used to estimate the response of I. typographus populations to changing stand conditions. In stands located in the zone above 800 m a.s.l. where both the level defoliation and tree mortality were higher, the infestation density and body length of I. typographus were higher than in the zone below 800 m a.s.l., where stands were less damaged. Contrarily, the gallery length was higher in lower montane zone, where lower infestation densities and body length values were found. A proposed mechanism for this interaction, which is attributed mainly to better breeding conditions for I. typographus populations in weakened stands, is presented and discussed. more...

We describe a series of experiments on the protection of Norway spruce (Picea abies (L.) Karst.) logs and standing trees against Ips typographus L. (Coleoptera: Scolytidae). The tested protective materials were applied 1) at point sources and 2) area-covering using zeolite-based dispensers. We performed 11 terrestrial and one aerial application (using a helicopter) between 1992 and 2001. We gradually replaced polyethylene-bag verbenone dispensers by composite dispensers releasing verbenone and non-host volatiles (NHV: green leaf volatiles, trans-conophthorin, and C8-alcohols). Many experiments did not give statistically significant results, due to the low number of true replicates and the spatial heterogeneity of beetle attacks. The protection of horizontal objects like logs or lying trees with anti-attractants was not always successful. In the future, positive results can be expected with an area covering spray applied by zeolite dispensers containing mixtures of verbenone and NHV. A similar approach could probably be used in aerial spraying of anti-attractants. We have succeeded in our attempt to protect zones of standing spruce trees from I. typographus attacks. We used dispensers with a combination of verbenone and a full blend of NHV compounds. The protection is not complete, but in both 2000 and 2001, the treatment significantly decreased the probability of the insect attack on trees by 60–80 %. more...

This paper presents the results of a research project concerning bark beetle populations in Norway spruce stands managed under a nature protection regime in national parks in Tatra Mountains in Poland and Slovakia. The preliminary data on bark beetle occurrence and related selected stand characteristics are presented. The dynamics of a bark beetle outbreak that occurred from 1994–97 in the stands localized on both sides of the state border and in various nature protection regimes is analyzed retrospectively. The data concerning the tree/stand characteristics, i.e. DBH and increment of trees are discussed in relation to its potential role in the mechanism for the spread of bark beetle populations. The patterns of the spatial distribution of trees attacked during the research period (1999–2001) are described. more...

An international cooperative project on distribution of ozone in the Carpathian Mountains, Central Europe was conducted from 1997 to 1999. Results of that project indicated that in large parts of the Carpathian Mountains, concentrations of ozone were elevated and potentially phytotoxic to forest vegetation. That study led to the establishment of new long-term studies on ecological changes in forests and other ecosystems caused by air pollution in the Retezat Mountains, Southern Carpathians, Romania and in the Tatra Mountains, Western Carpathians on the Polish–Slovak border. Both of these important mountain ranges have the status of national parks and are Man & the Biosphere Reserves. In the Retezat Mountains, the primary research objective was to evaluate how air pollution may affect forest health and biodiversity. The main research objective in the Tatra Mountains was to evaluate responses of natural and managed Norway spruce forests to air pollution and other stresses. Ambient concentrations of ozone (O3), sulfur dioxide (SO2), nitrogen oxides (NOx) as well as forest health and biodiversity changes were monitored on densely distributed research sites. Initial monitoring of pollutants indicated low levels of O3, SO2, and NOx in the Retezat Mountains, while elevated levels of O3 and high deposition of atmospheric sulfur (S) and nitrogen (N) have characterized the Tatra Mountains. In the Retezat Mountains, air pollution seems to have little effect on forest health; however, there was concern that over a long time, even low levels of pollution may affect biodiversity of this important ecosystem. In contrast, severe decline of Norway spruce has been observed in the Tatra Mountains. Although bark beetle seems to be the immediate cause of that decline, long-term elevated levels of atmospheric N and S depositions and elevated O3 could predispose trees to insect attacks and other stresses. European and US scientists studied pollution deposition, soil and plant chemistry, O3-sensitive plant species, forest insects, and genetic changes in the Retezat and Tatra Mountains. Results of these investigations are presented in a GIS format to allow for a better understanding of the changes and the recommendations for effective management in these two areas. Keywords: Air quality, Ozone, Biodiversity, Ecology, Forests, Carpathian Mountains, Poland, Slovakia, Romania more...

In 2011-2013, trials on the use of the entomopathogenic fungus Beauveria bassiana against bark beetle (Ips typographus) populations were carried out under open field conditions in Norway spruce stands suffering from an outbreak in the Beskid Żywiecki Mts. in Poland. Modified pheromone traps were deployed to capture and thereafter release fungus-infected bark beetles to the forest environment. Infested spruce trees felled next to the traps remained unaffected by the transmission of the fungus to insect populations. Direct spraying or dusting of lying trap logs and suspended caged rearing bolts did not have any effect on spruce infestation by I. typographus, its reproduction success and development or natural enemies inside the bark. A very small effect on mortality rates of target as well as non-target insects overwintering in the dusted litter was observed. Treated stands, unlike control stands, were indirectly affected by the treatment, evidenced by the reduction of tree mortality due to bark beetle infestation. At present, no recommendations concerning the potential use of the fungus in forest protection can be given. However such an environmentally friendly approach represents a promising future prospect. more...

Spruce is regarded as the only host plant of Ips duplicatus in Central Europe, whereas this beetle excep - tionally occurs on pine in Siberia. Its occurrence on Pinus strobus and Pinus sylvestris was discovered in the eastern part of the Czech Republic and in southern Poland, where the population density of Ips duplicatus has been increased for a long time on Norway spruce. However, all cases concerned only single trees which were growing in forest complexes with spruce dominance. The most likely explanation is merely a consequence of the typical host plant shortage. more...

In 2010–2012, investigations on Ips typographus populations were carried out in Norway spruce stands recently affected by bark beetle outbreak in the Beskid Żywiecki Mts. in Poland. The aim of the study was to test the usefulness of several traits describing I. typographus populations for evaluation of their actual outbreak tendency. Infestation density, sex ratio, gallery length, progeny number and beetle length were used as the traits. Trait variability was analyzed in relation to infested tree mortality in the current year of observation and outbreak tendency defined by the comparison of data on tree mortality in the current year and that in the year before. The highest infestation density was found in the stands representing the highest tree mortality in the current year and in those characterized by decreasing outbreak tendency. The gallery system with 2 maternal galleries dominated. The sex ratio of attacking beetles inclined towards females (63.8%) and remained stable during 3 years of observations; the highest percentage of females was found in locations being in stabilization/latency outbreak phase. The length of maternal galleries was somewhat negatively affected by infestation density and positively correlated with the number of progeny in the gallery. The average beetle length was 4.800 mm (± 0.293), ranging between 3.718 and 5.817 mm and being the highest in the uppermost class of tree mortality recorded in the current year of observation. The shortest beetles were collected in the stands with increasing outbreak tendency, and slightly longer – in the stands with outbreak stable and decreasing tendencies. None of the traits tested can be selected as a direct indicator for prediction of outbreak tendency in I. typographus populations. Possible reasons of variability in the analyzed traits are discussed. The traits indicate that I. typographus in the study area represent very high reproductive potential, thus the risk of repeated outbreak is very high. This record was migrated from the OpenDepot repository service in June, 2017 before shutting down., {"references":["Anderbrant O. 1985. Intraspecific competition affecting parents and offspring in the bark beetle Ips typographus. Oikos, 45, 89–98.\n\nAnderbrant O. 1990. Gallery construction and oviposition of the bark beetle Ips typographus (Coleoptera: Scolytidae) at different breeding densities. Ecological Entomology, 15, 1–8.\n\nAnderbrant O., Schlyter F. 1989. Causes and effects of \nindividual quality in bark beetles. Holarctic Ecology, 12 (4), 488–493.\n\nAtkins M.D. 1975. On factors affecting the size, fat content and behaviour of a scolytid. Zeitschrift für angewandte Entomologie, 78, 209–218.\n\nBotterweg P.F. 1982. 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Interactions within and between species \nat different densities of the bark beetle Ips typographus and its predator Thanasimus formicarius. Entomologia Experimentalis et Applicata, 71, 133–143."]} more...

BACCARA is a research project supported by the European Community’s Seventh Framework Programme, planned for four years (2009–2012). The main goal of BACCARA is to build the tools that will enable forest managers and policy makers to evaluate the risk of European forest biodiversity and productivity loss under climate change. The paper is aimed to present the goals and approach of this project, with special regard to the Carpathian Case. The main outreach from BACCARA project will be the Guidelines “What-to-Grow” and “What-to-Combat”, addressed to the forest managers and policy makers. more...

In the experiment eight populations of Picea abies were chosen at 100 m intervals between 500 m and 1200 m altitude a.s.l.. In each population wood core samples were collected from 14–19 trees (126 cores total), and measured using a Corim Maxi device. At four of the eight sites (every 200 m in elevation between 500 m and 1100 m a.s.l.), the diversity of ground vegetation was evaluated, and temperature was recorded at every 100 m of altitude. The highest average radial increment of spruce occurred between the altitudes 800–1000 m a.s.l., which is probably the optimum for spruce. The larger increment indices observed at higher altitudes may signify a high growth potential of spruce. It may also suggest a recent upward shift of the optimum growth zone for this tree species. In 15 phytosociological records, the presence of 148 plant species forming plant associations: Dentario glandulosae- Fagetum typicum (sub-mountainous and mountainous form) and Abieti-Piceetum, and community Abies alba-Rubus hirtus, was documented. No relationship was found between ground vegetation species diversity (expressed by Shannon-Wiener index) and levels of stand diversity. The vegetation species diversity varied with the elevation above sea level: the highest plant diversity was found at 500 m a.s.l., and decreased with increasing altitude. The potential increase in air temperatures may result in changes to the altitudinal range of many plant species including trees, and consequently in an upward shift of the boundaries of plant zones; in this case the sub-mountainous and lower mountainous forest zone. In this region, the optimal zone for Norway spruce may be restricted to the highest elevations. more...

Predicting climate-driven changes in plant distribution is crucial for biodiversity conservation and management under recent climate change. Climate warming is expected to induce movement of species upslope and towards higher latitudes. However, the mechanisms and physiological processes behind the altitudinal and latitudinal distribution range of a tree species are complex and depend on each tree species features and vary over ontogenetic stages. We investigated the altitudinal distribution differences between juvenile and adult individuals of seven major European tree species along elevational transects covering a wide latitudinal range from southern Spain (37°N) to northern Sweden (67°N). By comparing juvenile and adult distributions (shifts on the optimum position and the range limits) we assessed the response of species to present climate conditions in relation to previous conditions that prevailed when adults were established. Mean temperature increased by 0.86 °C on average at our sites during the last decade compared with previous 30-year period. Only one of the species studied, Abies alba, matched the expected predictions under the observed warming, with a maximum abundance of juveniles at higher altitudes than adults. Three species, Fagus sylvatica, Picea abies and Pinus sylvestris, showed an opposite pattern while for other three species, such as Quercus ilex, Acer pseudoplatanus and Q. petraea, we were no able to detect changes in distribution. These findings are in contrast with theoretical predictions and show that tree responses to climate change are complex and are obscured not only by other environmental factors but also by internal processes related to ontogeny and demography. © 2013 John Wiley & Sons Ltd., Financial support was provided by the European Union with the project BACCARA (FP7-226299, 7FP) and the Spanish Ministry for Innovation and Science with the grant Consolider Montes (CSD2008_00040). more...

Background: Despite empirical support for an increase in ecosystem productivity with species diversity in synthetic systems, there is ample evidence that this relationship is dependent on environmental characteristics, especially in structurally more complex natural systems. Empirical support for this relationship in forests is urgently needed, as these ecosystems play an important role in carbon sequestration. Methodology/Principal Findings: We tested whether tree wood production is positively related to tree species richness while controlling for climatic factors, by analyzing 55265 forest inventory plots in 11 forest types across five European countries. On average, wood production was 24% higher in mixed than in monospecific forests. Taken alone, wood production was enhanced with increasing tree species richness in almost all forest types. In some forests, wood production was also greater with increasing numbers of tree types. Structural Equation Modeling indicated that the increase in wood production with tree species richness was largely mediated by a positive association between stand basal area and tree species richness. Mean annual temperature and mean annual precipitation affected wood production and species richness directly. However, the direction and magnitude of the influence of climatic variables on wood production and species richness was not consistent, and vary dependent on forest type. Conclusions: Our analysis is the first to find a local scale positive relationship between tree species richness and tree wood production occurring across a continent. Our results strongly support incorporating the role of biodiversity in management and policy plans for forest carbon sequestration. © 2013 Vilà et al. more...

International audience; Due to climate change, forests are likely to face new hazards, which may require adaptation of our existing silvicultural practices. However, it is difficult to imagine a forest management approach that can simultaneously minimize all risks of damage. Multicriteria decision analysis (MCDA) has been developed to help decision makers choose between actions that require reaching a compromise among criteria of different weights. We adapted this method and produced a multicriteria risk analysis (MCRA) to compare the risk of damage associated with various forest management systems with a range of management intensity. The objective was to evaluate the effect of four forest management alternatives (FMAs) (i.e., close to nature, extensive management with combined objectives, intensive even-aged plantations, and short-rotation forestry for biomass production) on biotic and abiotic risks of damage in eight regional case studies combining three forest biomes (Boreal, Continental, Atlantic) and five tree species ( Eucalyptus globulus, Pinus pinaster, Pinus sylvestris, Picea sitchensis, and Picea abies) relevant to wood production in Europe. Specific forest susceptibility to a series of abiotic (wind, fire, and snow) and biotic (insect pests, pathogenic fungi, and mammal herbivores) hazards were defined by expert panels and subsequently weighted by corresponding likelihood. The PROMETHEE ranking method was applied to rank the FMAs from the most to the least at risk. Overall, risk was lower in short-rotation forests designed to produce wood biomass, because of the reduced stand susceptibility to the most damaging hazards. At the opposite end of the management intensity gradient, close-to-nature systems also had low overall risk, due to lower stand value exposed to damage. Intensive even-aged forestry appeared to be subject to the greatest risk, irrespective of tree species and bioclimatic zone. These results seem to be robust as no significant differences in relative ranking of the four FMAs were detected between the combinations of forest biomes and tree species. more...

During an outbreak in the second half of the 1990s, the infestation pattern of Ips duplicatus C.R. Sahlb. on standing trees in the Silesian Upland (southern Poland), was seen to be different from the pattern observed in the north-eastern spruce range. The “southern” type can be characterised by (i) the abundance of I. duplicatus galleries in lower parts of stems (including the basal parts of stems), and (ii) co-occurrence and high spatial competition with Ips typographus L. The “southern” type of infestation seems to be temporal in nature, related to the high abundance of I. duplicatus during the progradation and culmination phase of its outbreak. more...

This paper is a review of fundamental information on bark beetles and their interactions with several predisposing factors (air pollution, drought/temperature interactions, windthrows, management activities) that are thought to contribute to the outbreaks in the High Tatra Mountains. The findings of many research projects indicate that the impact of air pollution on bark beetle populations is indirect and complex and that the disturbances in the physiology and natural resistance of trees may be of crucial importance to bark beetle population dynamics. An active forest protection approach is needed to be applied to the secondary Norway spruce forests affected in the past by human activity. Bark beetle populations in natural and near-natural forests (mainly in the upper montane zone) are regulated by natural mechanisms; bark beetles are therefore a natural factor contributing to forest development, including the transition of future generations of spruce. Przemysław Szmit more...

The results of the study on entomofauna infesting young (25– 45 years) Norway spruces (Picea abies [L.] Karst.) in the area formerly affected by forest decline in the Izerskie Mountains (Western Sudetes), are presented in the paper. Entomological analyses were carried out on tree sections (0.5m long) obtained from 50 trees (3 sections each) as well as during photoeclector rearing of tree samples (28 sections 0.5m long). Bark- and wood-boring insects of 21 species and 1 genus were found. The dominant species was Pityogenes chalcographus L. (88% frequency in field analyses) usually accompanied by Ips amitinus (68%). Both species frequently infested whole stems (found in all 3 sections in 62% of analyzed trees). In the group of predators and commensals, 13 species were found, with most frequent Corticeus linearis (Fabr.), Crypturgus spp. and Medetera signaticornis (Loew.). Among the parasitoids belonging to 7 species and 4 genera, Braconids and Pteromalids known as parasites of Scolytid bark beetles, were most common. Taking into consideration reccurence of natural processes such as insect outbreaks, probability of the scenario described in the paper, i.e. shifting bark beetle attack from old into young spruce stands after Ips typographus L. outbreak, is very high in the area of current decline of the Norway spruce in the Western Carpathians. Przemysław Szmit more...