Forest developmental trajectories in mountain pine beetle disturbed forests of Rocky Mountain National Park, Colorado

2011 ◽  
Vol 41 (4) ◽  
pp. 782-792 ◽  
Author(s):  
Matthew Diskin ◽  
Monique E. Rocca ◽  
Kellen N. Nelson ◽  
Carissa F. Aoki ◽  
W.H. Romme

A mountain pine beetle (Dendroctonus ponderosae Hopkins) epidemic has caused widespread mortality of lodgepole pine (Pinus contorta Dougl. ex Loud. var. latifolia Engelm.) trees across western North America,. We characterized the initial effects of beetle-induced mortality on forest structure and composition in Rocky Mountain National Park, Colorado. In 2008, we surveyed stand structure and tree species composition across lodgepole pine dominated forests in the western portion of the Park. We defined five lodgepole pine forest types to describe variability in pre-epidemic forest conditions. This forested landscape appears to be resilient to the effects of the beetle. Surviving trees, including both canopy trees and saplings, were plentiful in most of the post-epidemic forests, even after accounting for anticipated future mortality. Subalpine fir (Abies lasiocarpa (Hook.) Nutt.), Engelmann spruce (Picea engelmannii Parry ex Engelm.), and aspen (Populus tremuloides Michx.) had modestly higher relative abundances after the epidemic. Lodgepole pine remained the dominant species on approximately 85% of the landscape. The impact of the outbreak on forest structure and composition varied considerably among the five forest types, suggesting that post-epidemic forest developmental trajectories will vary according to pre-outbreak stand characteristics. Active management efforts to regenerate lodgepole pine forests, e.g., tree planting, will likely not be necessary on this landscape.

Author(s):  
W. Romme ◽  
J. Yavitt ◽  
D. Knight

A research project was initiated in 1980 to study the effects of outbreaks of the mountain pine beetle (Dendroctonus ponderosae Hopkins) on lodgepole pine forest (Pinus contorta Dougl. ssp. latifolia) in Yellowstone National Park and surrounding areas. This native insect apparently has long been associated with lodgepole pine, and reports of small numbers of beetles can be found in Park records as early as 1925. However, in the late 1940's and early 1950's major outbreaks began to occur on the Caribou and Targhee National Forests immediately to the west and southwest of Yellowstone and Grand Teton National Parks. An outbreak in Grand Teton National Park and the adjacent Teton National Forest began in the 1950's, with an explosive increase in 1961 followed by an eventual subsidence in the late 1960's. The first major outbreak in Yellowstone National Park began in the late 1960's in the Bechler and South Entrance areas, reaching a peak there in 1970 and later declining. Yearly aerial surveys conducted thereafter showed a steady northward movement of the outbreak through the western half of the Park at a rate of 1 - 5 km per year. By 1978 the peak outbreak was centered around West Yellowstone, with hundreds of infested trees per hectare. The outbreak is now moving north and east along the Madison and Gibbon Rivers, with the greatest beetle populations currently in the vicinity of Madison Junction.


Author(s):  
W. Romme ◽  
J. Yavitt ◽  
D. Knight ◽  
J. Fedders

A research project was initiated in 1980 to study the effects of outbreaks of the mountain pine beetle (Dendroctonus ponderosae) on lodgepole pine forest (Pinus contorta spp. latifolia) in Yellowstone National Park and surrounding areas. This native bark beetle recently has killed millions of trees over thousands of square kilometers in the central and northern Rocky Mountains. Major outbreaks first occurred in Grand Teton National Park in the 1950's and in Yellowstone National Park in the 1960's. The outbreak in Yellowstone Park is still spreading.


2018 ◽  
Vol 48 (10) ◽  
pp. 1159-1170 ◽  
Author(s):  
Jodi N. Axelson ◽  
Brad C. Hawkes ◽  
Lara van Akker ◽  
René I. Alfaro

The mountain pine beetle (MPB; Dendroctonus ponderosae Hopkins) is a native bark beetle and a major disturbance agent in western North American forests. In the 1970s and 1980s, a MPB outbreak occurred in Waterton Lakes National Park (WLNP) in southwestern Alberta. The MPB outbreak resulted in variable levels of mortality of mature lodgepole pine (Pinus contorta var. latifolia Engelm. ex S. Watson), reducing density, volume, and basal area of overstory trees. By 2010, lodgepole pine was proportionally no longer the dominant overstory species, with increases in non-pine conifer and broadleaf species. The MPB susceptibility index decreased in most stands over time, especially in stands with the highest MPB-caused mortality. Downed woody material was characterized by fine and coarse fuel mass and volume, which both increased from 2002 to 2010, and the abundance of coarse fuels was highest in 2010, nearly 30 years after peak MPB activity. Density of understory saplings and small regeneration increased from 2002 to 2010 and was dominated by non-pine conifer and broadleaf species; lodgepole pine was nearly absent. Hierarchical clustering using 2010 MPB susceptibility and composition data characterized biological legacies remaining after the MPB outbreak. These legacies suggest multiple successional trajectories in WLNP dominated by species other than lodgepole pine. The MPB outbreak resulted in greater heterogeneity in composition and structure and suggests that stands have been resilient to this disturbance.


Author(s):  
W. Romme ◽  
J. Yavitt ◽  
D. Knight ◽  
J. Fedders

A research project was initiated in 1980 to study the effects of outbreaks of the mountain pine beetle (Dendroctonus ponderosae) on lodgepole pine forests (Pinus contorta spp. latifolia) in Yellowstone National Park and surrounding areas. This native bark beetle recently has killed millions of trees over thousands of square kilometers in the central and northern Rocky Mountains. Major outbreaks first occurred in Grand Teton National Park in the 1950's and in Yellowstone National Park in the 1960's. The outbreak in Yellowstone Park is still spreading.


2011 ◽  
Vol 41 (12) ◽  
pp. 2403-2412 ◽  
Author(s):  
Daniel M. Kashian ◽  
Rebecca M. Jackson ◽  
Heather D. Lyons

Extensive outbreaks of the mountain pine beetle ( Dendroctonus ponderosae Hopkins) will alter the structure of many stands that will likely be attacked again before experiencing a stand-replacing fire. We examined a stand of lodgepole pine ( Pinus contorta var. latifolia Engelm. ex S. Watson) in Grand Teton National Park currently experiencing a moderate-level outbreak and previously attacked by mountain pine beetle in the 1960s. Consistent with published studies, tree diameter was the main predictor of beetle attack on a given tree, large trees were preferentially attacked, and tree vigor, age, and cone production were unimportant variables for beetle attack at epidemic levels. Small trees killed in the stand were killed based mainly on their proximity to large trees and were likely spatially aggregated with large trees as a result of the previous outbreak. We concluded that the driving factors of beetle attack and their spatial patterns are consistent across outbreak severities but that stand structure altered by the previous outbreak had implications for the current outbreaks in the same location. This study should catalyze additional research that examines how beetle-altered stand structure affects future outbreaks — an important priority for predicting their impacts under climate change scenarios that project increases in outbreak frequency and extent.


2008 ◽  
Vol 101 (1) ◽  
pp. 39-48 ◽  
Author(s):  
Xuejun Pan ◽  
Dan Xie ◽  
Richard W. Yu ◽  
Jack N. Saddler

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