scholarly journals Potential Solar Radiation as a Driver for Bark Beetle Infestation on a Landscape Scale

Forests ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 604 ◽  
Author(s):  
Pavel Mezei ◽  
Mária Potterf ◽  
Jaroslav Škvarenina ◽  
Jakob Gulddahl Rasmussen ◽  
Rastislav Jakuš
Keyword(s):  
Solar Radiation ◽  
Bark Beetle ◽  
Bark Beetles ◽  
Tree Mortality ◽  
Prediction Models ◽  
Meteorological Data ◽  
Spatiotemporal Pattern ◽  
Tatra Mountains ◽  
Elevation Model ◽  
High Tatra Mountains

In recent decades, Norway spruce (Picea abies L. Karst.) forests of the High Tatra Mountains have suffered unprecedented tree mortality caused by European spruce bark beetle (Ips typographus L.). Analysis of the spatiotemporal pattern of bark beetle outbreaks across the landscape in consecutive years can provide new insights into the population dynamics of tree-killing insects. A bark beetle outbreak occurred in the High Tatra Mountains after a storm damaged more than 10,000 ha of forests in 2004. We combined yearly Landsat-derived bark beetle infestation spots from 2006 to 2014 and meteorological data to identify the susceptibility of forest stands to beetle infestation. We found that digital elevation model (DEM)-derived potential radiation loads predicted beetle infestation, especially in the peak phase of beetle epidemic. Moreover, spots attacked at the beginning of our study period had higher values of received solar radiation than spots at the end of the study period, indicating that bark beetles prefer sites with higher insolation during outbreak. We conclude that solar radiation, easily determined from the DEM, better identified beetle infestations than commonly used meteorological variables. We recommend including potential solar radiation in beetle infestation prediction models.

scholarly journals Drivers of Spruce Bark Beetle (Ips typographus) Infestations on Downed Trees after Severe Windthrow

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1290
Author(s):  
Branislav Hroššo ◽  
Pavel Mezei ◽  
Mária Potterf ◽  
Andrej Majdák ◽  
Miroslav Blaženec ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Bark Beetle ◽  
Bark Beetles ◽  
Ips Typographus ◽  
Wind Damage ◽  
Stem Length ◽  
Local Conditions ◽  
Spruce Bark Beetle ◽  
Management Actions ◽  
Spruce Bark

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.

scholarly journals Managing bark beetle outbreaks (Ips typographus, Dendroctonus spp.) in conservation areas in the 21st century

2016 ◽  
Vol 77 (4) ◽  
pp. 352-357
Author(s):  
Dominik Kulakowski
Keyword(s):  
North America ◽  
Bark Beetle ◽  
Bark Beetles ◽  
Tree Mortality ◽  
Forest Health ◽  
Scientific Data ◽  
Timber Production ◽  
Conservation Areas ◽  
Silvicultural Treatments ◽  
Social Scientific

Abstract Forests in Europe and North America are being affected by large and severe outbreaks of bark beetles, which have caused widespread concern about forest health and have led to proposals for tree removal in affected or susceptible forests. Any such intervention, as well as broader decisions of whether any active interventions are appropriate, should be based on the best scientific data. This is true for all forests, including those whose purposes include timber production, watershed protection, biogeochemical function and recreation, and especially protected and conservation areas as the latter often provide particularly unique and important cultural, social, scientific and other ecosystem services. Here, I summarize peer-reviewed literature on the effects of bark beetle outbreaks and on silvicultural treatments aimed at mitigating beetle-induced tree mortality. From an objective scientific perspective, beetle outbreaks do not destroy forests. Instead, in many cases they play an important role in promoting wildlife, biodiversity and other ecological services. The best available data indicate that logging in conservation areas is unlikely to stop ongoing bark beetle outbreaks and instead may be more ecologically detrimental to the forests than the outbreaks themselves. If the purpose of a forest is timber production, then logging is desirable and can be planned based on appropriate analyses of timber yield and economic profit. However, in areas in which conservation is the determined goal, it is recommended that cutting trees be limited to removing hazards, such as trees that might fall in areas of high human activity in order to limit property damage and personal injury. Based on extensive research in Europe and North America, logging beetle-affected forests is inconsistent with most conservation goals.

Ethanol accumulation during severe drought may signal tree vulnerability to detection and attack by bark beetles

2014 ◽  
Vol 44 (6) ◽  
pp. 554-561 ◽  
Author(s):  
Rick G. Kelsey ◽  
D. Gallego ◽  
F.J. Sánchez-García ◽  
J.A. Pajares
Keyword(s):  
Bark Beetle ◽  
Bark Beetles ◽  
Tree Mortality ◽  
Carbon Allocation ◽  
Pinus Halepensis ◽  
Severe Drought ◽  
Tissue Water Content ◽  
Tissue Water ◽  
Mediterranean Pine ◽  
Pine Shoot Beetles

Tree mortality from temperature-driven drought is occurring in forests around the world, often in conjunction with bark beetle outbreaks when carbon allocation to tree defense declines. Physiological metrics for detecting stressed trees with enhanced vulnerability prior to bark beetle attacks remain elusive. Ethanol, water, monoterpene concentrations, and composition were examined in the phloem and sapwood of drought-stressed Aleppo pine (Pinus halepensis Mill.) freshly attacked by mature Mediterranean pine shoot beetles (Tomicus destruens (Wollaston, 1865)) and in neighboring unattacked trees. The attacked trees were more water-stressed and contained, on average, 2.1 and 2.4 times more ethanol in the phloem and sapwood, respectively, than the neighboring attack-free trees. This response is consistent with the known attraction of T. destruens to ethanol. Most monoterpene concentrations in the phloem, but not sapwood, were greater in tissues of attacked trees, whereas compositional differences were minor between the two tree groups for both tissues. Tissue water content explained much of the variation in phloem monoterpene concentrations, which increased as water in the phloem declined, suggesting that higher constitutive quantities existed in the more stressed trees prior to the attacks. Monoterpenes may have contributed to host tree selection by T. destruens, but their potential influence is considered less important than that of ethanol based on beetle responses to these compounds in previous trapping studies. This is the first report of elevated ethanol concentrations in tissues of trees experiencing natural drought stress and suggests that ethanol measurements in severely water-stressed trees may allow early detection of those most vulnerable to bark beetle attack.

scholarly journals SPME collection and GC-MS analysis of volatiles emitted during the attack of male Polygraphus poligraphus (Coleoptera, Curcolionidae) on Norway spruce

2015 ◽  
Vol 70 (9-10) ◽  
pp. 265-273 ◽  
Author(s):  
Rizan Rahmani ◽  
Erik Hedenström ◽  
Martin Schroeder
Keyword(s):  
Norway Spruce ◽  
Bark Beetle ◽  
Bark Beetles ◽  
Tree Mortality ◽  
Solid Phase ◽  
Enantiomeric Excess ◽  
Enantiomeric Purity ◽  
Spruce Bark ◽  
Volatile Organic ◽  
Over Time

Abstract Tree mortality caused by bark beetles has increased in recent decades in both Europe and North America. In a large recent outbreak in central Sweden the bark beetle Polygraphus poligraphus was often found together with the spruce bark beetle Ips typographus in killed trees. To increase the understanding of the aggregation behavior of P. poligraphus we used solid phase microextraction (SPME) to collect volatile organic compounds (VOCs) released from single P. poligraphus males, with and without added females, colonizing Norway spruce stem sections and analyzed the sampled compounds by combined gas chromatography and mass spectrometry (GC-MS). High amounts of terpinen-4-ol, a substance found in the hindguts of P. poligraphus males in earlier studies, were released by colonizing males. The emission of both enantiomers of terpinen-4-ol was monitored by GC-MS over time as the males aged in the absence and presence of females. Single males emitted (R)-(–)-terpinen-4-ol for up to 60 days in high enantiomeric purity but the enantiomeric excess (ee) varied between males, and also for the same individual, over time from 96.3% to 99.3% ee. In the presence of females, males also emitted terpinen-4-ol for up to 50 days but now in lower amounts and with lower enantiomeric purity varying from 67.7% ee to 99.3% ee. Small quantities of other volatile compounds were emitted from the colonizing beetles including cis- and trans-4-thujanol, both of which were previously shown to be present in the hindguts of males. In earlier studies frontalin was found to attract P. poligraphus, but in our study it was not identified among emitted compounds from colonizing beetles.

scholarly journals Bark beetle outbreak enhances biodiversity and foraging habitat of native bees in alpine landscapes of the southern Rocky Mountains

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Thomas Seth Davis ◽  
Paul R. Rhoades ◽  
Andrew J. Mann ◽  
Terry Griswold
Keyword(s):  
Bark Beetle ◽  
Forest Structure ◽  
Bark Beetles ◽  
Large Scale ◽  
Tree Mortality ◽  
Growing Season ◽  
Floral Resources ◽  
Foraging Habitat ◽  
Pollinator Community ◽  
Large Scale Disturbance

Abstract Landscape-scale bark beetle outbreaks alter forest structure with direct and indirect effects on plants and animals in forest ecosystems. Using alpine spruce forest and a native bee community as a study system, we tested how tree mortality from bark beetles impacts bee foraging habitats and populations. Bees were collected across the growing season (early-, middle-, and late-season) for two years using passive trapping methods, and collections were used to analyze patterns in species abundances and diversity. Three important findings emerged: (1) forest stands that were post-outbreak had 62% higher floral density and 68% more floral species during peak bloom, respectively, than non-affected stands; (2) bee captures were highest early-season (June) and were not strongly affected by bark beetle outbreak; however, mean number of bee species and Shannon–Weiner diversity were significantly higher in post-outbreak stands and this effect was pronounced early in the growing season. Corresponding analysis of β-diversity indicated higher accumulation of bee biodiversity in post-outbreak stands and a turnover in the ratio of Bombus: Osmia; (3) bee captures were linked to variation in foraging habitat, but number of bee species and diversity were more strongly predicted by forest structure. Our results provide evidence of increased alpine bee biodiversity in post-outbreak stands and increased availability of floral resources. We conclude that large-scale disturbance from bark beetle outbreaks may drive shifts in pollinator community composition through cascading effects on floral resources, mediated via mortality of overstory trees.

scholarly journals Effectiveness of Two Systemic Insecticides for Protecting Western Conifers from Mortality Due to Bark Beetle Attack

2010 ◽  
Vol 25 (4) ◽  
pp. 181-185 ◽  
Author(s):  
Donald M. Grosman ◽  
Christopher J. Fettig ◽  
Carl L. Jorgensen ◽  
A. Steven Munson
Keyword(s):  
Bark Beetle ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Bark Beetles ◽  
Tree Mortality ◽  
Dendroctonus Brevicomis ◽  
Emamectin Benzoate ◽  
The Third ◽  
Systemic Insecticides ◽  
Pine Beetle

Abstract Bark beetles (Coleoptera: Curculionidae, Scolytinae) are important tree mortality agents in western coniferous forests. Protection of individual trees from bark beetle attack has historically involved applications of liquid formulations of contact insecticides to the tree bole using hydraulic sprayers. More recently, researchers looking for more portable and environmentally safe alternatives have examined the effectiveness of injecting small quantities of systemic insecticides directly into trees. In this study, we evaluated trunk injections of experimental formulations of emamectin benzoate and fipronil for preventing tree mortality due to attack by western pine beetle (Dendroctonus brevicomis LeConte) on ponderosa pine (Pinus ponderosa Dougl. ex Laws.) in California, mountain pine beetle (Dendroctonus ponderosae Hopkins) on lodgepole pine (Pinus contorta Dougl. ex Loud.) in Idaho, and spruce beetle (D. rufipennis [Kirby]) on Engelmann spruce (Picea engelmannii Parry ex Engelm.) in Utah. Fipronil appeared ineffective for protecting P. ponderosa from mortality due to D. brevicomis over the 3 years in California because of insufficient mortality of untreated, baited control trees the first 2 years and high mortality of the fipronil-treated trees in the third year. Emamectin benzoate was effective in providing protection of P. ponderosa from D. brevicomis during the third year following a single application. To our knowledge, this is the first demonstration of the successful application of a systemic insecticide for protecting individual conifers from mortality due to bark beetle attack in the western United States. Estimates of efficacy could not be made during both field seasons in P. contorta because of insufficient mortality in control trees. Both emamectin benzoate and fipronil were ineffective for protecting P. engelmannii from D. rufipennis. Lower ambient and soil temperatures and soil moisture may have limited chemical movement and thus efficacy at the Idaho and Utah sites.

scholarly journals An attempt to use the fungus Beauveria bassiana (Bals.) Vuill. in forest protection against the bark beetle Ips typographus (L.) in the field

2015 ◽  
Vol 76 (1) ◽  
pp. 5-17 ◽  
Author(s):  
Wojciech Grodzki ◽  
Mieczysław Kosibowicz
Keyword(s):  
Beauveria Bassiana ◽  
Bark Beetle ◽  
Bark Beetles ◽  
Tree Mortality ◽  
Ips Typographus ◽  
Forest Environment ◽  
Forest Protection ◽  
Spruce Stands ◽  
Insect Populations ◽  
Fungus Beauveria Bassiana

Abstract 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.

scholarly journals GIS-AIDED GEOGRAPHICAL AND METEOROLOGICAL DATA OVERVIEW OF SOLAR RADIATION MAPPING FOR MALAYSIA – AN EXPLANATORY STUDY BASED ON SOLAR RADIATION PREDICTION MODELING USING NEURAL NETWORK APPROACH

2021 ◽  
Vol 83 (6) ◽  
pp. 19-33
Author(s):  
Mohd Rizman Sultan Mohd ◽  
Fazlina Ahmat Ruslan ◽  
Juliana Johari
Keyword(s):  
Neural Networks ◽  
Solar Radiation ◽  
Prediction Models ◽  
Spatial Information ◽  
Meteorological Data ◽  
Coefficient Of Determination ◽  
Network Approach ◽  
Prediction Modeling ◽  
Neural Network Approach ◽  
Input Parameters

Solar radiation mapping has used geographical and meteorological data. To obtain geographical and meteorological data, a Geographic Information System (GIS) is required. GIS is defined as an integrated geographic resource that presents data in terms of spatial information. This data is important for Neural Networks as it will be used as input parameters for the development of solar radiation prediction models. Solar radiation prediction is one way to map the sun's rays in certain places where there are insufficient resources or space to build a complete solar radiation measurement station. Since predictions about solar radiation require meteorological and geographical data, this paper will give an overview of GIS-assisted geographical and meteorological data to be used as input parameters for solar radiation mapping which will eventually be used as input for prediction models developed for the whole country of Malaysia using Neural Networks. Based on the results, the prediction model developed managed to obtain a coefficient of determination, R2 value of 0.9329.

scholarly journals Applicability of a vegetation indices-based method to map bark beetle outbreaks in the High Tatra Mountains

2015 ◽  
Vol 58 (2) ◽  
pp. 1 ◽  
Author(s):  
Mária Havašová ◽  
Tomáš Bucha ◽  
Ján Ferenčík ◽  
Rastislav Jakuš
Keyword(s):  
Bark Beetle ◽  
Vegetation Indices ◽  
Tatra Mountains ◽  
High Tatra Mountains

scholarly journals Changes in Transpiration and Leaf Water Potential in Douglas-Fir Trees following Douglas-Fir Beetle Attack and Mechanical Girdling

Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1722
Author(s):  
Javier E. Mercado ◽  
Robert T. Walker ◽  
Scott Franklin ◽  
Shannon L. Kay ◽  
Susana Karen Gomez ◽  
...  
Keyword(s):  
Water Potential ◽  
Bark Beetle ◽  
Leaf Water Potential ◽  
Bark Beetles ◽  
Tree Mortality ◽  
Douglas Fir ◽  
Leaf Water ◽  
Lodgepole Pines ◽  
And Control ◽  
Phloem Feeding

Bark beetles and their associated fungi kill trees readily, but we often ignore which organism is the leading cause of tree mortality. While phloem feeding beetles inhibit photosynthate transport, their associated fungi block the tracheids disrupting transpiration. Within the family Pinaceae, knowledge of tree physiological decline following bark beetle and associated fungi colonization is limited to the genus Pinus. Here we investigate the physiological response of Pseudotsuga (P. menziesii) to bark beetles or its fungi. We hypothesized that fungi block water transport in Douglas-fir causing faster mortality than by bark beetle activity alone. We successfully lured Douglas-fir beetle to attack a subset of trees in our experimental area using pheromones and compared Beetle-Killed trees with mechanically Girdled, and Control trees. During spring snowmelt, nine months after treatments were applied, Control, Girdled, and five trees that Survived beetle attack had higher transpiration rates and less negative pre-dawn water potential than five Beetle-Killed trees. Declines in transpiration and leaf water potential in our Beetle-Killed trees occurred much earlier than those in studies of beetle-attacked lodgepole pines, suggesting stronger defensive traits in Douglas-fir. Our data suggest that, as in pines, bark beetle-associated fungi are the leading cause of mortality in Douglas-fir beetle-attacked trees.

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