Limber pine in the central and southern Rocky Mountains: Stand conditions and interactions with blister rust, mistletoe, and bark beetles

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.

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Assessing the potential for maladaptation during active management of limber pine populations: a common garden study detects genetic differentiation in response to soil moisture in the Southern Rocky Mountains

Canadian Journal of Forest Research ◽

10.1139/cjfr-2014-0399 ◽

2015 ◽

Vol 45 (4) ◽

pp. 496-505 ◽

Cited By ~ 5

Author(s):

Erin M. Borgman ◽

Anna W. Schoettle ◽

Amy L. Angert

Keyword(s):

Soil Moisture ◽

Genetic Differentiation ◽

Carbon Isotope ◽

Rocky Mountains ◽

Source Region ◽

Common Garden ◽

Active Management ◽

Needle Length ◽

Southern Rocky Mountains ◽

Limber Pine

Active management is needed to sustain healthy limber pine (Pinus flexilis E. James) forests in the Southern Rocky Mountains (henceforth, Southern Rockies), as they are threatened by the interaction of the mountain pine beetle (Dendroctonus ponderosae Hopkins) epidemic, climate change, and the spread of the non-native pathogen that causes white pine blister rust disease (Cronartium ribicola A. Dietr.). Appropriate source material for restoration and proactive introduction needs to be selected, taking into account potential genetic differentiation that would hamper management success. We conducted a common garden study in a greenhouse to determine the degree of genetic differentiation among limber pine populations in the Southern Rockies. We evaluated the differential responses of populations from northern and southern portions of the Southern Rockies to different moisture regimes during early seedling growth by measuring primary needle length, stem diameter, water potential, biomass allocation between root and shoot, and carbon isotope ratios (δ13C; a proxy for water-use efficiency). There were significant (p < 0.05) effects of source region for root length, stem diameter, needle length, and total dry mass, with seedlings from southern sources bigger than seedlings from northern sources. Furthermore, there was a marginally significant interaction between soil moisture regime and source region for carbon isotope ratio (p = 0.0778), suggesting possible local adaptation. These data indicate that genetic differentiation exists among populations in the Southern Rockies, potentially increasing the risk of maladaptation when moving seed far from its source for active management.

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A method for estimating white pine blister rust canker age on limber pine in the central Rocky Mountains

Forest Pathology ◽

10.1111/j.1439-0329.2008.00575.x ◽

2009 ◽

Vol 39 (3) ◽

pp. 177-191 ◽

Cited By ~ 7

Author(s):

Holly S. J. Kearns ◽

William R. Jacobi ◽

Brian W. Geils

Keyword(s):

Rocky Mountains ◽

White Pine Blister Rust ◽

White Pine ◽

Limber Pine ◽

Blister Rust ◽

Central Rocky Mountains

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

Remote Sensing ◽

10.3390/rs13061089 ◽

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.

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