Thirty year change in lodgepole and lodgepole/mixed conifer forest structure following 1980s mountain pine beetle outbreak in western Colorado, USA

2012 ◽  
Vol 280 ◽  
pp. 93-102 ◽  
Author(s):  
Kristen A. Pelz ◽  
Frederick W. Smith
2013 ◽  
Vol 10 (8) ◽  
pp. 5451-5463 ◽  
Author(s):  
A. Mathys ◽  
T. A. Black ◽  
Z. Nesic ◽  
G. Nishio ◽  
M. Brown ◽  
...  

Abstract. The recent mountain pine beetle (MPB) outbreak has had an impact on the carbon (C) cycling of lodgepole pine forests in British Columbia. This study examines how partial harvesting as a forest management response to MPB infestation affects the net ecosystem production (NEP) of a mixed conifer forest (MPB-09) in Interior BC. MPB-09 is a 70-year-old stand that was partially harvested in 2009 after it had been attacked by MPB. Using the eddy-covariance technique, the C dynamics of the stand were studied over two years and compared to an adjacent clear-cut (MPB-09C) over the summertime. The annual NEP at MPB-09 increased from −108 g C m−2 in 2010 to −57 g C m−2 in 2011. The increase of NEP was due to the associated increase in annual gross ecosystem photosynthesis (GEP) from 812 g C m−2 in 2010 to 954 g C m−2 in 2011, exceeding the increase in annual respiration (Re) from 920 g C m−2 to 1011 g C m−2 during the two years. During the four month period between June and September 2010, NEP at MPB-09C was −103 g C m−2, indicating high C losses in the clear-cut. MPB-09 was a C sink during the growing season of both years, increasing from 9 g C m−2 in 2010 to 47 g C m−2 in 2011. The increase of NEP in the partially harvested stand amounted to a recovery corresponding to a 26% increase in the maximum assimilation rate in the second year. This study shows that retaining the healthy residual forest can result in higher C sequestration of MPB-attacked stands compared to clear-cut harvesting.


2013 ◽  
Vol 10 (3) ◽  
pp. 4927-4968 ◽  
Author(s):  
A. Mathys ◽  
T. A. Black ◽  
Z. Nesic ◽  
G. Nishio ◽  
M. Brown ◽  
...  

Abstract. The recent mountain pine beetle (MPB) outbreak has had an impact on the carbon (C) cycling of lodgepole pine forests in British Columbia. This study examines how partial harvesting as a forest management response to MPB infestation affects the net ecosystem production (NEP) of a mixed conifer forest (MPB-09) in Interior BC. MPB-09 is a 70-yr old stand that was partially harvested in 2009 after it had been attacked by MPB. Using the eddy-covariance technique, the C dynamics of the stand were studied over two years and compared to an adjacent clearcut (MPB-09C) over the growing season. The annual NEP at MPB-09 increased from −108 g C m−2 in 2010 to −57 g C m−2 in 2011. The increase of NEP was due to the associated increase in annual gross ecosystem photosynthesis (GEP) from 812 g C m−2 in 2010 to 954 g C m−2 in 2011 exceeding the increase in annual respiration (Re) from 920 g C m−2 to 1011 g C m−2 during the two years. During the growing season of 2010, NEP at MPB-09C was −132 g C m−2 indicating high C losses in the clearcut. MPB-09 was a C sink during the growing season of both years, increasing from 9 g C m−2 in 2010 to 47 g C m−2 in 2011. The increase of NEP in the partially-harvested stand amounted to a recovery corresponding to a 25% increase in the maximum assimilation rate in the second year. This study shows that retaining the healthy residual forest can result in higher C sequestration of MPB-attacked stands compared to clearcut harvesting.


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.


Ecosphere ◽  
2015 ◽  
Vol 6 (5) ◽  
pp. art79 ◽  
Author(s):  
Scott L. Stephens ◽  
Jamie M. Lydersen ◽  
Brandon M. Collins ◽  
Danny L. Fry ◽  
Marc D. Meyer

2010 ◽  
Vol 40 (9) ◽  
pp. 1803-1814 ◽  
Author(s):  
Danny L. Fry ◽  
Scott L. Stephens

Descriptions of spatial patterns are important components of forest ecosystems, providing insights into functions and processes, yet basic spatial relationships between forest structures and fuels remain largely unexplored. We used standardized omnidirectional semivariance modeling to examine the spatial pattern of fuels and forest structure measured in a systematic nested plot grid covering 144 ha. Forest structure variables were spatially dependent at scales ranging from 62 to 572 m. Cross-variograms of fuels and forest structure showed both positive and negative correlations, ranging from 0.04 to 0.67. Notably, fine fuels were correlated positively and negatively with forest structure variables of white fir ( Abies concolor (Gord. & Glend.) Lindl. ex Hildebr.) and Jeffrey pine ( Pinus jeffreyi Balf.), respectively. Old-growth Jeffrey pine – mixed conifer forest within the study area exhibited both identifiable spatial correlations and high stand-level spatial heterogeneity, as demonstrated by the influence of outliers on the underlying spatial pattern. The spatial dependency of fuels with species-specific variables suggests that less common species may have a large influence in the characterization of forest attributes and that fuel classifications may be improved by accounting for the spatial distributions of overstory species. Spatial correlations have many applications to forest management, including the classification and mapping of forest structure, establishing guidelines for fuel treatments, and restoration of old-growth forest ecosystems.


2011 ◽  
Vol 261 (6) ◽  
pp. 989-994 ◽  
Author(s):  
Phillip J. van Mantgem ◽  
Nathan L. Stephenson ◽  
Eric Knapp ◽  
John Battles ◽  
Jon E. Keeley

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