Stand Characteristics and Downed Woody Debris Accumulations Associated with a Mountain Pine Beetle (Dendroctonus ponderosae Hopkins) Outbreak in Colorado

Authors

Jennifer G. Klutsch
Jose F. Negron
Sheryl L. Costello
Charles C. Rhoades
Daniel R. West
John Popp
Rick Caissie

Document Type

Article

Journal/Book Title/Conference

Forest Ecology and Management

Publication Date

2009

Issue

5

Volume

258

First Page

641

Last Page

649

Abstract

Lodgepole pine (Pinus contorta Dougl. ex Loud.)-dominated ecosystems in north-central Colorado are undergoing rapid and drastic changes associated with overstory tree mortality from a current mountain pine beetle (Dendroctonus ponderosae Hopkins) outbreak. To characterize stand characteristics and downed woody debris loads during the first 7 years of the outbreak, 221 plots (0.02 ha) were randomly established in infested and uninfested stands distributed across the Arapaho National Forest, Colorado. Mountain pine beetle initially attacked stands with higher lodgepole pine basal area, and lower density and basal area of Engelmann spruce (Picea engelmannii [Parry]), and subalpine fir (Abies lasiocarpa (Hook.) Nutt. var. lasiocarpa) compared to uninfested plots. Mountain pine beetle-affected stands had reduced total and lodgepole pine stocking and quadratic mean diameter. The density and basal area of live overstory lodgepole declined by 62% and 71% in infested plots, respectively. The mean diameter of live lodgepole pine was 53% lower than pre-outbreak in infested plots. Downed woody debris loads did not differ between uninfested plots and plots currently infested at the time of sampling to 3 or 4–7 years after initial infestation, but the projected downed coarse wood accumulations when 80% of the mountain pine beetle-killed trees fall indicated a fourfold increase. Depth of the litter layer and maximum height of grass and herbaceous vegetation were greater 4–7 years after initial infestation compared to uninfested plots, though understory plant percent cover was not different. Seedling and sapling density of all species combined was higher in uninfested plots but there was no difference between infested and uninfested plots for lodgepole pine alone. For trees ≥2.5 cm in diameter at breast height, the density of live lodgepole pine trees in mountain pine beetle-affected stands was higher than Engelmann spruce, subalpine fir, and aspen, (Populus tremuloides Michx.), in diameter classes comprised of trees from 2.5 cm to 30 cm in diameter, suggesting that lodgepole pine will remain as a dominant overstory tree after the bark beetle outbreak.

Comments

Originally published by Elsevier. Publisher's PDF and HTML fulltext available through remote link. View and Print This Publication at: http://www.fs.fed.us/rm/pubs_other/rmrs_2009_klutsch_j001.pdf

Recommended Citation

Klutsch, J., Negron, J., Costello, S., Rhoades, C., West, D., Popp, J. and Caissie, R. (2009). Stand characteristics and downed woody debris accumulations associated with a mountain pine beetle (Dendroctonus ponderosae Hopkins) outbreak in Colorado. Forest Ecology and Managment, 258(5): 641-649.