scholarly journals Improved Identification and New Records of Dendroctonus Bark Beetles Attacking Pinus contorta in the Subalpine Forest of the Southern Rocky Mountains

Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 656
Author(s):  
Javier E. Mercado
Keyword(s):  
Rocky Mountains ◽  
Bark Beetles ◽  
Pinus Contorta ◽  
Subalpine Forest ◽  
Attack Behavior ◽  
Dendroctonus Rufipennis ◽  
Southern Rocky Mountains ◽  
Attack Pattern ◽  
Detection And Identification ◽  
The Impact

Research Highlights: Atypical and poorly understood attacks by Dendroctonus rufipennis (Kirby) to Pinus contorta Doug. ex Loudon were detected in the southern Rocky Mountains (SRM). The phenomenon is confirmed across all examined area. Its reproduction is described for the first time as well as the first attacks of D. adjunctus Blandf. in that host. Improved detection and diagnostics of D. rufipennis will allow a simpler, and efficient identification of the species. It will improve the detection capacity by pest detection specialists and entomologists, which will increase our understanding of the phenomena within and beyond the known range. Background and Objectives: In addition to D. ponderosae Hopk. other Dendroctonus species, sometimes together, attacked P. contorta that grew intermixed with Picea engelmannii in the SRM’ subalpine forest. The identification of these beetles was difficult. The goal was to improve the detection and identification of the species from similar Dendroctonus spp. attacking that host and to uncover biological facts about the phenomena. Materials and Methods: Dendroctonus attacking P. contorta were collected along the entire SRM, their attack signs and behavior were recorded. These characteristics were revised from those in the literature and new characters were introduced and tested. Results: The identification of Dendroctonus bark beetles attacking P. contorta in the SRM was improved using revised and new characters including attack signs, attack behavior, and adult beetle characters. An improved identification key couplet is presented to effectively distinguish D. murrayanae from D. rufipennis. Conclusions: Simplified insect identifications that are both accessible to users with different levels of expertise and are based on insect characters, their attack pattern, and signs, like the present, improve detection of insects of interest. Efficient insect detections allow a better understanding of the capabilities they have and the impact they cause to the woodland ecosystems we study, protect, and manage around the globe.

scholarly journals Effects of Bark Beetle Outbreaks on Forest Landscape Pattern in the Southern Rocky Mountains, U.S.A

2021 ◽  
Vol 13 (6) ◽  
pp. 1089
Author(s):  
Kyle C. Rodman ◽  
Robert A. Andrus ◽  
Cori L. Butkiewicz ◽  
Teresa B. Chapman ◽  
Nathan S. Gill ◽  
...  
Keyword(s):  
Bark Beetle ◽  
Rocky Mountains ◽  
Bark Beetles ◽  
Tree Mortality ◽  
Landscape Connectivity ◽  
Basal Area ◽  
Resource Provisioning ◽  
Wildlife Habitat ◽  
Subalpine Forest ◽  
Southern Rocky Mountains

Since the late 1990s, extensive outbreaks of native bark beetles (Curculionidae: Scolytinae) have affected coniferous forests throughout Europe and North America, driving changes in carbon storage, wildlife habitat, nutrient cycling, and water resource provisioning. Remote sensing is a crucial tool for quantifying the effects of these disturbances across broad landscapes. In particular, Landsat time series (LTS) are increasingly used to characterize outbreak dynamics, including the presence and severity of bark beetle-caused tree mortality, though broad-scale LTS-based maps are rarely informed by detailed field validation. Here we used spatial and temporal information from LTS products, in combination with extensive field data and Random Forest (RF) models, to develop 30-m maps of the presence (i.e., any occurrence) and severity (i.e., cumulative percent basal area mortality) of beetle-caused tree mortality 1997–2019 in subalpine forests throughout the Southern Rocky Mountains, USA. Using resultant maps, we also quantified spatial patterns of cumulative tree mortality throughout the region, an important yet poorly understood concept in beetle-affected forests. RF models using LTS products to predict presence and severity performed well, with 80.3% correctly classified (Kappa = 0.61) and R2 = 0.68 (RMSE = 17.3), respectively. We found that ≥10,256 km2 of subalpine forest area (39.5% of the study area) was affected by bark beetles and 19.3% of the study area experienced ≥70% tree mortality over the twenty-three year period. Variograms indicated that severity was autocorrelated at scales < 250 km. Interestingly, cumulative patch-size distributions showed that areas with a near-total loss of the overstory canopy (i.e., ≥90% mortality) were relatively small (<0.24 km2) and isolated throughout the study area. Our findings help to inform an understanding of the variable effects of bark beetle outbreaks across complex forested regions and provide insight into patterns of disturbance legacies, landscape connectivity, and susceptibility to future disturbance.

Last glacial–interglacial environments in the southern Rocky Mountains, USA and implications for Younger Dryas-age human occupation

2012 ◽  
Vol 77 (1) ◽  
pp. 96-103 ◽  
Author(s):  
Christy E. Briles ◽  
Cathy Whitlock ◽  
David J. Meltzer
Keyword(s):  
Rocky Mountains ◽  
Fire History ◽  
Younger Dryas ◽  
Late Glacial ◽  
Subalpine Forest ◽  
Glacial Period ◽  
Last Glacial ◽  
Southern Rocky Mountains ◽  
Late Glacial Period ◽  
Fire Activity

The last glacial-interglacial transition (LGIT; 19–9 ka) was characterized by rapid climate changes and significant ecosystem reorganizations worldwide. In western Colorado, one of the coldest locations in the continental US today, mountain environments during the late-glacial period are poorly known. Yet, archaeological evidence from the Mountaineer site (2625 m elev.) indicates that Folsom-age Paleoindians were over-wintering in the Gunnison Basin during the Younger Dryas Chronozone (YDC; 12.9–11.7 ka). To determine the vegetation and fire history during the LGIT, and possible explanations for occupation during a period thought to be harsher than today, a 17-ka-old sediment core from Lily Pond (3208 m elev.) was analyzed for pollen and charcoal and compared with other high-resolution records from the southern Rocky Mountains. Widespread tundra and Picea parkland and low fire activity in the cold wet late-glacial period transitioned to open subalpine forest and increased fire activity in the Bølling–Allerød period as conditions became warmer and drier. During the YDC, greater winter snowpack than today and prolonged wet springs likely expanded subalpine forest to lower elevations than today, providing construction material and fuel for the early inhabitants. In the early to middle Holocene, arid conditions resulted in xerophytic vegetation and frequent fire.

Toxicity of two Engelmann spruce (Pinaceae) monoterpene chemotypes from the southern Rocky Mountains to North American spruce beetle (Coleoptera: Scolytidae)

2020 ◽  
Vol 152 (6) ◽  
pp. 790-796
Author(s):  
Thomas Seth Davis
Keyword(s):  
Rocky Mountains ◽  
Picea Engelmannii ◽  
Dendroctonus Rufipennis ◽  
Probability Of Survival ◽  
Southern Rocky Mountains ◽  
Engelmann Spruce ◽  
Adult Body Mass ◽  
Spruce Beetle ◽  
Average Probability ◽  
Logit Function

AbstractEngelmann spruce, Picea engelmannii Parry ex Engelm. (Pinaceae), in the southern Rocky Mountains is composed of two distinct phloem monoterpene chemotypes that differ in relative abundances of multiple monoterpenes, particularly α-pinene and Δ3-carene (hereafter, the “α-pinene chemotype” and the “Δ3-carene chemotype”). Here, relative toxicity of these chemotypes is tested on spruce beetle (Dendroctonus rufipennis Kirby) (Coleoptera: Scolytinae), a phloeophagous herbivore that colonises trees of both types. Synthetic monoterpene blends representing each chemotype were tested across a range of concentrations (0, 10, 50, 100, 200, and 500 µg/L) in the lab, and probability of survival of adult beetles exposed to each blend was modelled using a logit function. Logit curves were solved to determine LC25, LC50, and LC75 of each monoterpene blend. On average, probability of beetle survival was lower when exposed to the Δ3-carene chemotype than when exposed to the α-pinene chemotype. However, both chemotypes were completely lethal to beetles at concentrations exceeding 100 µg/L. Adult body mass did not affect survival probability. It is concluded that spruce phloem chemotypes may differ in their toxicity to spruce beetles, with potential consequences for patterns of host-tree colonisation by spruce beetle.

Pre-Vashon fossil Coleoptera of Fraser age from the Fraser Lowland, British Columbia

1985 ◽  
Vol 22 (4) ◽  
pp. 498-505 ◽  
Author(s):  
R. F. Miller ◽  
A. V. Morgan ◽  
S. R. Hicock
Keyword(s):  
British Columbia ◽  
Pinus Ponderosa ◽  
Bark Beetles ◽  
Pinus Contorta ◽  
Subalpine Forest ◽  
Abies Lasiocarpa ◽  
Open Forest ◽  
Distribution Ranges ◽  
The Family ◽  
Open Ground

Samples of organic silt from post-Coquitlam Quadra sand at Port Moody and Mary Hill, British Columbia (dated at 18 300 and 18 700 years BP, respectively) were examined for insect remains and yielded small assemblages of beetles.At Port Moody species of the family Staphylinidae, whose members are often associated with moss or leaf litter, are the most abundant fossils present. Other specimens included open-ground beetles of the family Carabidae, as well as weevils (Curculionidae) and bark beetles (Scolytidae), which inhabit conifers. The assemblage appears to represent an open forest-floor community. Some of the species in this site have distribution ranges that do not include the Port Moody area today, but do occur in the interior of British Columbia and at higher altitude near the coast. One of the most numerous species, Micropeplus laticollis Mäklin, occurs in duff of conifers including Picea engelmannii, Abies lasiocarpa, Pinus ponderosa, and Pinus contorta. These trees are characteristic of the subalpine forest. The insect assemblage suggests an in situ deposit, subalpine in nature, probably in a cool but dry environment that developed during the short episode when this part of the Fraser Lowland was ice free between the Coquitlam and Vashon ice advances.The beetle assemblage from Mary Hill Quadra sediments probably indicates that a bog environment existed at that time; however, the lack of specific identifications precludes detailed paleoclimatic interpretation.

Drought-driven disturbance history characterizes a southern Rocky Mountain subalpine forest

2012 ◽  
Vol 42 (9) ◽  
pp. 1649-1660 ◽  
Author(s):  
R. Justin DeRose ◽  
James N. Long
Keyword(s):  
Vegetation Dynamics ◽  
Rocky Mountain ◽  
Subalpine Forest ◽  
Dendroctonus Rufipennis ◽  
Southern Rocky Mountains ◽  
Engelmann Spruce ◽  
Spruce Beetle ◽  
Drought Conditions ◽  
Recent Outbreak ◽  
Species Specific

The view that subalpine forest vegetation dynamics in western North America are “driven” by a particular disturbance type (i.e., fire) has shaped our understanding of their disturbance regimes. In the wake of a recent (1990s) landscape-extent spruce beetle ( Dendroctonus rufipennis Kirby) outbreak in the southern Rocky Mountains, we re-examined the temporal continuity in disturbance types and interactions and the possible role of drought on their occurrence by reconstructing antecedent disturbances for 11 sites across the Markagunt Plateau, southern Utah, USA. Multiple consistent lines of evidence suggested that historic fires were the primary antecedent disturbance, while relatively minor, stand-specific spruce beetle activity occurred later in stand development but prior to the recent outbreak. Unlike the recent outbreak, antecedent fires were spatially and temporally asynchronous over the period examined (~1600–2000). Reconstructed fire events primarily occurred during periods of prolonged drought. Similarly, historic spruce beetle activity, indicated by species-specific tree-ring release, and timing of Engelmann spruce ( Picea engelmannii Parry ex Engelm.) death dates from the recent outbreak were related to drought conditions. Vegetation dynamics on this landscape were strongly driven by historic fires and the recent spruce beetle outbreak, and drought conditions likely influenced the occurrence of both disturbance types.

Pezizella chapmanii n.sp., a discomycete associated with bark beetle galleries in western conifers

1977 ◽  
Vol 55 (8) ◽  
pp. 888-891 ◽  
Author(s):  
H. S. Whitney ◽  
A. Funk
Keyword(s):  
Pseudotsuga Menziesii ◽  
Bark Beetle ◽  
Picea Glauca ◽  
Bark Beetles ◽  
Pinus Contorta ◽  
Western Canada ◽  
Agar Culture ◽  
Dendroctonus Rufipennis ◽  
Conidial State

Pezizella chapmanii n.sp. (Helotiales) is described from apothecia found in the galleries of various bark beetles in conifers of western Canada; viz., Dendroctonus rufipennis Kirby galleries in Picea glauca (Moench) Voss; D. ponderosae Hopkins galleries in Pinus contorta var. latifolia Engelmann and in P. ponderosa Laws.; D. murrayanae Hopkins galleries in P. contorta var. latifolia; and D. pseudotsugae Hopkins galleries in Pseudotsuga menziesii (Mirb.) Franco. In agar culture, a prominent Malbranchea conidial state is produced.

Dynamics of an old-growth, fire-initiated, subalpine forest in southern interior British Columbia: tree-ring reconstruction of 2 year cycle spruce budworm outbreaks

2002 ◽  
Vol 32 (11) ◽  
pp. 1947-1960 ◽  
Author(s):  
Roberta Parish ◽  
Joseph A Antos
Keyword(s):  
British Columbia ◽  
Tree Ring ◽  
Host Species ◽  
Pinus Contorta ◽  
Ring Width ◽  
Spruce Budworm ◽  
Subalpine Forest ◽  
Abies Lasiocarpa ◽  
Tree Ring Reconstruction ◽  
The Impact

Tree-ring width chronologies of three species from a 330-year-old subalpine forest were used to reconstruct outbreaks of 2 year cycle spruce budworm (Choristoneura biennis Freeman). The growth of host species, Engelmann spruce (Picea engelmannii Parry ex Engelm.) and subalpine fir (Abies lasiocarpa (Hook.) Nutt.), was compared with that of the nonhost, lodgepole pine (Pinus contorta Dougl. ex Loud.) with and without the removal of the effects of climate on growth. Seven periods, 1989–1991, 1943–1957, 1911–1927, 1869–1875, 1839–1861, 1823–1829, 1785–1801, were identified in which the growth of both host species was reduced relative to the non-host; this includes the single known outbreak from 1944 to 1956. Spectral analysis indicated a periodicity for growth reduction of the host relative to non-host species of ca. 45 years for both spruce and fir. For three periods, the known outbreak in the 1940–1950s, and two inferred outbreaks in the 1910–1920s and 1840–1850s, we calculated the four measures of radial growth first proposed by Brubaker and Greene (L.B. Brubaker and S.K. Greene. 1979. Can. J. For. Res. 9: 95–105): the maximum rate of growth loss, 1-year and 5-year losses, and the rate and time to recovery. Growth losses were greater for fir than for spruce during all three periods. During the 1940–1950s, growth losses were severe, but losses were less in the 1910–1920s. The impact of C. biennis has varied among outbreak periods but, overall, has made a pronounced contribution to present stand conditions. Our work suggests that budworms have been a frequent agent of disturbance with major effects on forest dynamics in southern British Columbia, especially in spruce–fir forests when long periods occur between fires.

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