Spatial variability in tree regeneration after wildfire delays and dampens future bark beetle outbreaks

Climate change is altering the frequency and severity of forest disturbances such as wildfires and bark beetle outbreaks, thereby increasing the potential for sequential disturbances to interact. Interactions can amplify or dampen disturbances, yet the direction and magnitude of future disturbance interactions are difficult to anticipate because underlying mechanisms remain poorly understood. We tested how variability in postfire forest development affects future susceptibility to bark beetle outbreaks, focusing on mountain pine beetle (Dendroctonus ponderosae) and Douglas-fir beetle (Dendroctonus pseudotsugae) in forests regenerating from the large high-severity fires that affected Yellowstone National Park in Wyoming in 1988. We combined extensive field data on postfire tree regeneration with a well-tested simulation model to assess susceptibility to bark beetle outbreaks over 130 y of stand development. Despite originating from the same fire event, among-stand variation in forest structure was very high and remained considerable for over a century. Thus, simulated emergence of stands susceptible to bark beetles was not temporally synchronized but was protracted by several decades, compared with stand development from spatially homogeneous regeneration. Furthermore, because of fire-mediated variability in forest structure, the habitat connectivity required to support broad-scale outbreaks and amplifying cross-scale feedbacks did not develop until well into the second century after the initial burn. We conclude that variability in tree regeneration after disturbance can dampen and delay future disturbance by breaking spatiotemporal synchrony on the landscape. This highlights the importance of fostering landscape variability in the context of ecosystem management given changing disturbance regimes.

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Failure of ovarian development in the Douglas-fir bark beetle, Dendroctonus pseudotsugae; an analysis of gut proteases and female-specific proteins

Canadian Journal of Zoology ◽

10.1139/z71-156 ◽

1971 ◽

Vol 49 (7) ◽

pp. 1021-1024 ◽

Cited By ~ 2

Author(s):

T. S. Sahota

Keyword(s):

High Activity ◽

Bark Beetle ◽

Methyl Ether ◽

Bark Beetles ◽

Ovarian Development ◽

Proteolytic Enzymes ◽

Douglas Fir ◽

Dendroctonus Pseudotsugae ◽

Specific Proteins ◽

Female Specific

The failure of ovarian development in Douglas-fir bark beetles denied of their natural gallery environment and maintained on host bark chips was investigated. Such insects possessed a high activity of proteolytic enzymes in their guts but relatively small amounts of female-specific proteins both in haemolymph and the oocytes. Topical application of farnesyl methyl ether did not increase the activity of gut proteases but resulted in increased amounts of female-specific proteins in haemolymph and ovaries. Thus it appears that the Douglas-fir bark beetles maintained on bark chips do not suffer from an inability to break down the ingested proteins, but synthesize and transfer less than normal amounts of female-specific proteins to the developing oocytes.

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DIFFERENTIAL BIOACTIVITY OF CONOPHTHORIN ON FOUR SPECIES OF NORTH AMERICAN BARK BEETLES (COLEOPTERA: SCOLYTIDAE)

The Canadian Entomologist ◽

10.4039/ent132649-5 ◽

2000 ◽

Vol 132 (5) ◽

pp. 649-653 ◽

Cited By ~ 21

Author(s):

Dezene P.W. Huber ◽

John H. Borden ◽

Nicole L. Jeans-Williams ◽

Regine Gries

Keyword(s):

Bark Beetle ◽

Bark Beetles ◽

Dependent Manner ◽

Dendroctonus Pseudotsugae ◽

Dendroctonus Rufipennis ◽

Pine Engraver ◽

Dryocoetes Confusus ◽

Baited Traps ◽

Spruce Beetle ◽

Dose Dependent

AbstractThe angiosperm bark volatile, conophthorin, was tested at release rates of 3.0 and 0.3 mg/24 h against the Douglas-fir beetle, Dendroctonus pseudotsugae Hopkins, the spruce beetle, Dendroctonus rufipennis (Kirby), the pine engraver, Ips pint (Say), and the western balsam bark beetle, Dryocoetes confusus Swaine (all Coleoptera: Scolytidae). The responses of D. pseudotsugae, I. pini, and (in one of two experiments) female D. confusus to attractant-baited traps were disrupted by conophthorin in a dose-dependent manner. Dendroctonus rufipennis was not disrupted by conophthorin. Our results extend the repellent bioactivity of conophthorin to Ips DeGeer spp. and confirm earlier experiments with D. pseudotsugae. Conophthorin may have some utility in protecting susceptible timber from bark beetle attack.

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Responses of Ips pini (Say), Pityogenes knechteli Swaine and Associated Beetles (Coleoptera) to Host Monoterpenes in Stands of Lodgepole Pine

Journal of Entomological Science ◽

10.18474/0749-8004-38.4.602 ◽

2003 ◽

Vol 38 (4) ◽

pp. 602-611 ◽

Cited By ~ 8

Author(s):

Daniel R. Miller ◽

John H. Borden

Keyword(s):

Bark Beetle ◽

Bark Beetles ◽

Mountain Pine Beetle ◽

Lodgepole Pine ◽

Behavioral Responses ◽

Ips Pini ◽

Host Volatiles ◽

Pine Engraver ◽

Pine Beetle

We conducted seven experiments in stands of mature lodgepole pine in southern British Columbia to elucidate the role of host volatiles in the semiochemical ecology of the pine engraver, Ips pini (Say) (Coleoptera: Scolytidae), with particular reference to the behavioral responses of predators and competing species of bark beetles. Our results demonstrated that the attraction of Ips pini and the bark beetle predators Lasconotus complex LeConte (Colydiidae), Thanasimus undatulus (Say) (Cleridae) and a Corticeus sp. (Tenebrionidae) were increased by 3-carene. In contrast, attraction of the bark beetle Pityogenes knechteli Swaine (Scolytidae) to ipsdienol was interrupted by 3-carene and α-pinene. Attraction of L. complex to ipsdienol was increased by γ-terpinene, a compound attractive to the mountain pine beetle, Dendroctonus ponderosae Hopkins (Scolytidae). Terpinolene interrupted the attraction of I. pini to ipsdienol.

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

Scientific Reports ◽

10.1038/s41598-020-73273-z ◽

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.

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Fire-injured ponderosa pine provide a pulsed resource for bark beetles

Canadian Journal of Forest Research ◽

10.1139/x2012-147 ◽

2012 ◽

Vol 42 (12) ◽

pp. 2022-2036 ◽

Cited By ~ 35

Author(s):

Ryan S. Davis ◽

Sharon Hood ◽

Barbara J. Bentz

Keyword(s):

Bark Beetle ◽

Pinus Ponderosa ◽

Ponderosa Pine ◽

Bark Beetles ◽

Mountain Pine Beetle ◽

Rocky Mountain ◽

Dendroctonus Brevicomis ◽

Brood Production ◽

Pine Beetle ◽

Tree Injury

Bark beetles can cause substantial mortality of trees that would otherwise survive fire injuries. Resin response of fire-injured northern Rocky Mountain ponderosa pine ( Pinus ponderosa Douglas ex P. Lawson & C. Lawson) and specific injuries that contribute to increased bark beetle attack susceptibility and brood production are unknown. We monitored ponderosa pine mortality and resin flow and bark beetle colonization and reproduction following a prescribed fire in Idaho and a wildfire in Montana. The level of fire-caused tree injury differed between the two sites, and the level of tree injury most susceptible to bark beetle attack and colonization also differed. Strip-attacked trees alive 3 years post-fire had lower levels of bole and crown injury than trees mass attacked and killed by bark beetles, suggesting that fire-injured trees were less well defended. Brood production of western pine beetle ( Dendroctonus brevicomis LeConte) did not differ between fire-injured and uninjured trees, although mountain pine beetle ( Dendroctonus ponderosae Hopkins) brood production was low in both tree types, potentially due to competition with faster developing bark beetle species that also colonized trees. Despite a large number of live trees remaining at both sites, bark beetle response to fire-injured trees pulsed and receded within 2 years post-fire, potentially due to a limited number of trees that could be easily colonized.

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The role of autoxidation of α-pinene in the production of pheromones of Dendroctonusponderosae (Coleoptera: Scolytidae)

Canadian Journal of Forest Research ◽

10.1139/x89-194 ◽

1989 ◽

Vol 19 (10) ◽

pp. 1275-1282 ◽

Cited By ~ 62

Author(s):

D. W. A. Hunt ◽

J. H. Borden ◽

B. S. Lindgren ◽

G. Gries

Keyword(s):

Bark Beetle ◽

Bark Beetles ◽

Mountain Pine Beetle ◽

Behavioral Activity ◽

Atmospheric Conditions ◽

Ambient Conditions ◽

Oxygenated Compounds ◽

Pine Trees ◽

Antiaggregation Pheromone ◽

Pinus Spp

The monoterpene α-pinene, a major component of the terpene composition of Pinus spp., has been reported to act as a host-produced kairomone for a variety of bark beetle species, including the mountain pine beetle, Dendroctonusponderosae Hopkins. However, our experiments indicate that α-pinene autoxidizes under normal temperature and atmospheric conditions to form significant quantities of trans-verbenol, an aggregation pheromone for many species of bark beetles. The quantities of α-pinene present in the resin that can flow from small wounds in pine trees appear to be sufficient to produce trans-verbenol at rates similar to those by female beetles that are actively synthesizing the compound.trans-Verbenol can then autoxidize rapidly to form verbenone, with the content of this compound reaching 8% within 13 weeks of exposure to air. Verbenone is often used by scolytids as an antiaggregation pheromone. Approximately 1.9% of the trans-verbenol and 2.7% of the verbenone found in Porapak Q aerations of phloem with boring spruce beetle, Dendroctonusrufipennis (Kirby), females, as well as 0.8% of the trans-verbenol and 0.8% of the verbenone found in aerations of phloem with boring D. ponderosae females, was due to the autoxidation of α-pinene and (or) the release of oxygenated compounds found in the phloem before bark beetle attack. The natural interconversion of α-pinene, trans-verbenol, and verbenone under ambient conditions suggests that many experiments involving the behavioral activity of these compounds require re-evaluation.

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Isolation of Fomitopsis pinicola from in-flight bark beetles (Coleoptera: Scolytidae)

Canadian Journal of Botany ◽

10.1139/b86-204 ◽

1986 ◽

Vol 64 (7) ◽

pp. 1507-1509 ◽

Cited By ~ 13

Author(s):

Thomas M. Pettey ◽

Charles Gardner Shaw

Keyword(s):

Ponderosa Pine ◽

Bark Beetles ◽

Mountain Pine Beetle ◽

Dendroctonus Brevicomis ◽

Fomitopsis Pinicola ◽

Dendroctonus Pseudotsugae ◽

Western Pine Beetle ◽

Pine Engraver ◽

Pine Beetle ◽

Pine Engraver Beetle

Isolations of Hymenomycetes on a preferential medium were attempted from preflight pine engraver beetles, Ips pini, and the following in-flight bark beetles: pine engraver beetle, I. pini; western pine beetle, Dendroctonus brevicomis; mountain pine beetle, Dendroctonus ponderosae; and red turpentine beetle, Dendroctonus valens. Thirty pine engraver beetles removed from ponderosa pine slash (preflight) yielded no hymenomycete. However, Hymenomycetes were isolated from 50 of 114 beetles (all species) trapped in flight; Fomitopsis pinicola from 44, and other unidentified suspected Hymenomycetes, from 6. Cryptoporus volvatus was not isolated from any of the in-flight beetles. Since most of these isolates were without clamps (monokaryotic), the beetles may acquire basidiospores after emergence from beetle galleries in coniferous trees as hypothesized previously for the Douglas-fir beetle, Dendroctonus pseudotsugae. The isolation of F. pinicola from all species of in-flight bark beetles indicates that these beetles may be important in the dissemination of this hymenomycete.

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Effectiveness of Permethrin Plus-C (Masterline ) and Carbaryl (Sevin SL ) for Protecting Individual, High-Value Pines (Pinus) From Bark Beetle Attack

Arboriculture & Urban Forestry ◽

10.48044/jauf.2006.031 ◽

2006 ◽

Vol 32 (5) ◽

pp. 247-252

Author(s):

Christopher Fettig ◽

Tom DeGomez ◽

Kenneth Gibson ◽

Christopher Dabney ◽

Robert Borys

Keyword(s):

Bark Beetle ◽

Pinus Ponderosa ◽

Bark Beetles ◽

Mountain Pine Beetle ◽

Individual Tree ◽

Tree Protection ◽

Standing Trees ◽

Field Season ◽

Individual Trees ◽

The Cost

Bark beetles (Coleoptera: Scolytidae) are commonly recognized as the most important mortality agent in western North American coniferous forests. High-value trees such as those located in residential, recreational, or administrative sites are particularly susceptible to attack. Regardless of landowner objectives, tree losses in these unique environments generally have a catastrophic impact. The value of these individual trees, the cost of removal, and the loss of aesthetics may justify protection until the main thrust of a bark beetle infestation subsides. This situation emphasizes the need for assuring that effective insecticides are available for individual tree protection. In this study, we assessed the efficacy of permethrin plus-C (Masterline®) and carbaryl (Sevin SL®) for protecting ponderosa, Pinus ponderosa Dougl. ex. Laws., lodgepole, P. contorta Dougl. ex Loud., and pinyon, P. edulis Engelm., pines from bark beetle attack during two field seasons. Masterline® was effective for protecting P. contorta from mountain pine beetle, Dendroctonus ponderosae Hopkins, attack for one field season. However, Sevin SL® was efficacious for two field seasons. An insufficient number of P. ponderosa and P. edulis control trees were killed to make definitive conclusions regarding efficacy in those systems. The data reported here regarding Masterline® is the first published report on its effectiveness for preventing bark beetle attack on standing trees. Masterline® appears to be an effective individual tree protection tool, but repeated applications will be necessary if multiyear control is desired.

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Distribution of Bark Beetle Attacks After Whitebark Pine Restoration Treatments: A Case Study

Western Journal of Applied Forestry ◽

10.1093/wjaf/20.2.110 ◽

2005 ◽

Vol 20 (2) ◽

pp. 110-116 ◽

Cited By ~ 8

Author(s):

Kristen M. Waring ◽

Diana L. Six

Keyword(s):

Bark Beetle ◽

Bark Beetles ◽

Mountain Pine Beetle ◽

Prescribed Burning ◽

High Elevation ◽

Permanent Plots ◽

Whitebark Pine ◽

White Pine Blister Rust ◽

Fire Exclusion ◽

A Site

Abstract Whitebark pine (Pinus albicaulis Engelm.), an important component of high elevation ecosystems in the western United States and Canada, is declining due to fire exclusion, white pine blister rust (Cronartium ribicola J.C. Fisch.), and mountain pine beetle (Dendroctonus ponderosae Hopkins). This study was conducted to evaluate the effects of whitebark pine restoration treatments on the distribution of bark beetle attacks. At a site in Idaho, silvicultural treatments were implemented in summer 1998 and 1999, with prescribed burning implemented in Oct. 1999. Permanent plots (400m2) were established during summer 1999 within each treatment and monitored for 4 years. Within plots, tree characteristics were measured and a bark beetle survey was conducted. Bark beetle attacks remained low throughout the study; however, there was an increase in bark beetle attacks in 2000 after the prescribed burning. By years 3 and 4, there were virtually no successful attacks. Although bark beetles were not a serious concern at the site assessed in this study, our results indicate that managers should consider and monitor the bark beetle component of these ecosystems when implementing restoration treatments. If baseline bark beetle populations are high at the time of implementation, our results indicate that increases in beetle activity would be expected in some treatments, perhaps requiring mitigation. West. J. Appl. For. 20(2):110–116.

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