Warming increased bark beetle‐induced tree mortality by 30% during an extreme drought in California

2021 ◽  
Author(s):  
Zachary J. Robbins ◽  
Chonggang Xu ◽  
Brian H. Aukema ◽  
Polly C. Buotte ◽  
Rutuja Chitra‐Tarak ◽  
...  
Keyword(s):  
Bark Beetle ◽  
Tree Mortality ◽  
Extreme Drought

scholarly journals Cross-scale interaction of host tree size and climatic water deficit governs bark beetle-induced tree mortality

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Michael J. Koontz ◽  
Andrew M. Latimer ◽  
Leif A. Mortenson ◽  
Christopher J. Fettig ◽  
Malcolm P. North
Keyword(s):  
Water Deficit ◽  
Sierra Nevada ◽  
Bark Beetle ◽  
Ponderosa Pine ◽  
Tree Mortality ◽  
Mortality Rates ◽  
Dendroctonus Brevicomis ◽  
Scale Interactions ◽  
Climatic Water Deficit ◽  
Host Mortality

AbstractThe recent Californian hot drought (2012–2016) precipitated unprecedented ponderosa pine (Pinus ponderosa) mortality, largely attributable to the western pine beetle (Dendroctonus brevicomis; WPB). Broad-scale climate conditions can directly shape tree mortality patterns, but mortality rates respond non-linearly to climate when local-scale forest characteristics influence the behavior of tree-killing bark beetles (e.g., WPB). To test for these cross-scale interactions, we conduct aerial drone surveys at 32 sites along a gradient of climatic water deficit (CWD) spanning 350 km of latitude and 1000 m of elevation in WPB-impacted Sierra Nevada forests. We map, measure, and classify over 450,000 trees within 9 km2, validating measurements with coincident field plots. We find greater size, proportion, and density of ponderosa pine (the WPB host) increase host mortality rates, as does greater CWD. Critically, we find a CWD/host size interaction such that larger trees amplify host mortality rates in hot/dry sites. Management strategies for climate change adaptation should consider how bark beetle disturbances can depend on cross-scale interactions, which challenge our ability to predict and understand patterns of tree mortality.

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.

scholarly journals Influence of different forest protection strategies on spruce tree mortality during a bark beetle outbreak

2017 ◽  
Vol 74 (4) ◽  
Author(s):  
Pavel Mezei ◽  
Miroslav Blaženec ◽  
Wojciech Grodzki ◽  
Jaroslav Škvarenina ◽  
Rastislav Jakuš
Keyword(s):  
Bark Beetle ◽  
Tree Mortality ◽  
Forest Protection ◽  
Protection Strategies

scholarly journals Use of MODIS NDVI Products to Map Tree Mortality Levels in Forests Affected by Mountain Pine Beetle Outbreaks

Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 811 ◽  
Author(s):  
Spruce ◽  
Hicke ◽  
Hargrove ◽  
Grulke ◽  
Meddens
Keyword(s):  
Linear Regression ◽  
Bark Beetle ◽  
Mountain Pine Beetle ◽  
Tree Mortality ◽  
Linear Regression Analysis ◽  
Severe Drought ◽  
Modis Ndvi ◽  
Modis Data ◽  
Mountain Pine ◽  
Pine Beetle

Extensive bark beetle outbreaks have recently occurred in western North American forests, resulting in overstory tree mortality across millions of hectares. Annual aerial surveys are currently used to operationally monitor bark beetle induced tree mortality, though this method is subjective and can exclude some forest areas. Daily Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data offer a potential alternative means to develop regional tree mortality maps. Accurate methods using such data could aid natural resource managers in surveys of forests with frequent overstory mortality, helping to prioritize forest treatment and restoration activities. This paper discusses a study to test the potential of using MODIS data to detect tree mortality. We developed and tested an approach to use 250-m resolution MODIS Normalized Difference Vegetation Index (NDVI) data products collected during a mountain pine beetle (MPB) outbreak and related tree mortality event in the northern Rocky Mountains of Colorado, USA. The 94 km2 study area is predominantly lodgepole pine forest with most of the MPB-caused mortality occurring between 2003 and 2008. We used a 2.4-m forest conditions map from 2008 aerial multispectral imagery to calculate percentage of mortality within 240-m pixels for use as reference data. Using either daily or 16-day products, MODIS NDVI change products were calculated for 2008 versus either 2000 or 2003 baselines. MODIS change products were used as predictors in linear regression analysis to assess correlation between MODIS data and the aerial percent forest mortality map. Depending on the MODIS product, linear regression analyses yielded r2 values ranging from 0.362 to 0.544 without outliers removed and from 0.406 to 0.570 with extreme outliers removed. Daily MODIS NDVI products from 2003 and 2008 were used with exponential regression to improve the r2 to 0.593. The project showed some MODIS NDVI data potential for mapping percent tree mortality in forests subjected to regional bark beetle outbreaks and severe drought.

Changes in the Summer Wild Bee Community Following a Bark Beetle Outbreak in a Douglas-fir Forest

2020 ◽  
Vol 49 (6) ◽  
pp. 1437-1448 ◽  
Author(s):  
Gabriel G Foote ◽  
Nathaniel E Foote ◽  
Justin B Runyon ◽  
Darrell W Ross ◽  
Christopher J Fettig
Keyword(s):  
United States ◽  
Species Richness ◽  
Bark Beetle ◽  
Tree Mortality ◽  
Canopy Cover ◽  
Douglas Fir ◽  
Wild Bee ◽  
Bee Community ◽  
Bee Communities ◽  
Bee Abundance

Abstract The status of wild bees has received increased interest following recent estimates of large-scale declines in their abundances across the United States. However, basic information is limited regarding the factors affecting wild bee communities in temperate coniferous forest ecosystems. To assess the early responses of bees to bark beetle disturbance, we sampled the bee community of a Douglas-fir, Pseudotsuga menziesii (Mirb.), forest in western Idaho, United States during a Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins (Coleoptera: Curculionidae), outbreak beginning in summer 2016. We resampled the area in summer 2018 following reductions in forest canopy cover resulting from mortality of dominant and codominant Douglas-fir. Overall, results from rarefaction analyses indicated significant increases in bee diversity (Shannon’s H) in 2018 compared to 2016. Results from ANOVA also showed significant increases in bee abundance and diversity in 2018 compared to 2016. Poisson regression analyses revealed percent tree mortality from Douglas-fir beetle was positively correlated with increases in total bee abundance and species richness, where community response variables displayed a cubic trend with percent tree mortality. Percent reduction in canopy cover from 2016 to 2018 was also correlated with bee species richness and diversity. These findings suggest that wild bee communities may benefit from changes in forest structure following bark beetle outbreaks.

scholarly journals Nonhost Angiosperm Volatiles and Verbenone Protect Individual Ponderosa Pines from Attack by Western Pine Beetle and Red Turpentine Beetle (Coleoptera: Curculionidae, Scolytinae)

2008 ◽  
Vol 23 (1) ◽  
pp. 40-45 ◽  
Author(s):  
Christopher J. Fettig ◽  
Christopher P. Dabney ◽  
Stephen R. McKelvey ◽  
Dezene P.W. Huber
Keyword(s):  
Benzyl Alcohol ◽  
Bark Beetle ◽  
Pinus Ponderosa ◽  
Tree Mortality ◽  
Dendroctonus Brevicomis ◽  
First Report ◽  
Western Pine Beetle ◽  
Dendroctonus Valens ◽  
Pine Beetle

Abstract Nonhost angiosperm volatiles (NAV) and verbenone were tested for their ability to protect individual ponderosa pines, Pinus ponderosa Dougl. ex. Laws., from attack by western pine beetle (WPB), Dendroctonus brevicomis LeConte, and red turpentine beetle (RTB), Dendroctonus valens LeConte (Coleoptera: Curculionidae, Scolytinae). A combination of (−)-verbenone and eight NAVs [benzyl alcohol, benzaldehyde, guaiacol, nonanal, salicylaldehyde, (E)-2-hexenal, (E)-2-hexen-1-ol, and (Z)-2-hexen-1-ol] (NAVV) significantly reduced the density of WPB attacks and WPB successful attacks on attractant-baited trees. A significantly higher percentage of pitchouts (unsuccessful WPB attacks) occurred on NAVV-treated trees during two of three sample dates. In addition, significantly fewer RTB attacks were observed on NAVV-treated trees during all sampling dates. The application of NAVV to individual ponderosa pines significantly reduced tree mortality, with only 4 of 30 attractant-baited trees dying from bark beetle attack while 50% mortality (15/30) was observed in the untreated, baited control. To our knowledge, this is the first report establishing the effectiveness of NAVs and verbenone for protecting individual ponderosa pines from WPB attack.

What explains landscape patterns of tree mortality caused by bark beetle outbreaks in Greater Yellowstone?

2011 ◽  
Vol 21 (5) ◽  
pp. 556-567 ◽  
Author(s):  
Martin Simard ◽  
Erinn N. Powell ◽  
Kenneth F. Raffa ◽  
Monica G. Turner
Keyword(s):  
Bark Beetle ◽  
Tree Mortality ◽  
Landscape Patterns ◽  
Greater Yellowstone

Blacks Mountain Experimental Forest: bark beetle responses to differences in forest structure and the application of prescribed fire in interior ponderosa pineThis article is one of a selection of papers from the Special Forum on Ecological Studies in Interior Ponderosa Pine — First Findings from Blacks Mountain Interdisciplinary Research.

2008 ◽  
Vol 38 (5) ◽  
pp. 924-935 ◽  
Author(s):  
Christopher J. Fettig ◽  
Robert R. Borys ◽  
Stephen R. McKelvey ◽  
Christopher P. Dabney
Keyword(s):  
Bark Beetle ◽  
Pinus Ponderosa ◽  
Prescribed Fire ◽  
Ponderosa Pine ◽  
Tree Mortality ◽  
Dendroctonus Brevicomis ◽  
Significant Difference ◽  
Pine Beetle ◽  
Low Diversity ◽  
High Diversity

Mechanical thinning and the application of prescribed fire are commonly used tools in the restoration of fire-adapted forest ecosystems. However, few studies have explored their effects on subsequent amounts of bark beetle caused tree mortality in interior ponderosa pine, Pinus ponderosa Dougl. ex P. & C. Laws. var. ponderosa. In this study, we examined bark beetle responses to creation of midseral (low diversity) and late-seral stages (high diversity) and the application of prescribed fire on 12 experimental units ranging in size from 76 to 136 ha. A total of 9500 (5.0% of all trees) Pinus and Abies trees died 2 years after treatment of which 28.8% (2733 trees) was attributed to bark beetle colonization. No significant difference in the mean percentage of trees colonized by bark beetles was found between low diversity and high diversity. The application of prescribed fire resulted in significant increases in bark beetle caused tree mortality (all species) and for western pine beetle, Dendroctonus brevicomis LeConte, mountain pine beetle, Dendroctonus ponderosae Hopkins, Ips spp., and fir engraver, Scolytus ventralis LeConte, individually. Approximately 85.6% (2339 trees) of all bark beetle caused tree mortality occurred on burned split plots. The implications of these and other results to sustainable forest management are discussed.

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.

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