Biological Evaluation Mountain Pine Beetle Roosevelt National Forest

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ISBN 13 :
Total Pages : 33 pages
Book Rating : 4.:/5 (13 download)

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Download or read book Biological Evaluation of Mountain Pine Beetle Activity on the Upper Fraser Analysis Area of Sulphur Ranger District, Arapaho-Roosevelt National Forests and Pawnee National Grassland, 2005 written by and published by . This book was released on 2005 with total page 33 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mountain pine beetle (MPB) epidemic in Grand County, Colorado, started in 1997 in the Williams Fork and Troublesome watersheds. Over the past seven years, losses of lodgepole pine to mountain pine beetle increased in these areas until most of the trees had been killed. Beginning in 2000, MPB-killed trees began to be detected in the Upper Fraser watershed. By 2004 large areas of lodgepole pine had been infested and killed by this beetle. The Sulphur Ranger District, on the Arapaho-Roosevelt National Forests and Pawnee National Grassland, is considering a variety of silvicultural treatments on approximately 2,400 acres of forest land to manage MPB impacts and remove beetle-infested and killed trees in designated areas in the Upper Fraser Analysis Area.‍?Lakewood Service Center Forest Health Management (LSC-FHM) surveyed ten of the proposed management units in the Upper Fraser Analysis Area to determine the level of mountain pine beetle infestation in these areas. LSC-FHM utilized aerial survey data and conducted on the ground surveys using strip samples and systematic variable radius plots. Ground surveys recorded the number of trees infested with mountain pine beetle in 2004 and the number of MPB-killed trees in 2003. Stand exam data also were used to determine stand susceptibility ratings for the management units.‍?Summary results from the aerial survey data indicated a rapid increase in MPB related mortality across the Upper Fraser Analysis Area over the last two years. The estimated area affected by MPB-caused mortality increased from 98 acres in 2002, to 1,588 acres in 2003, and 2,934 acres in 2004. Survey results estimate that the number of trees killed increased from 99 in 2002, to 656 in 2003, and 8,985 in 2004.‍?Ground survey data for the ten management units indicated that the MPB epidemic in the Upper Fraser Analysis Area is rapidly expanding in all management units, with a rapidly increasing number of trees infested and killed by the beetle. The number of MPB-infested trees ranged from 3 to 68 trees per acre. The 2004:2003 ratio of the number of trees infested by MPB ranged from 1.4:1 to 10.8:1, with nine of ten management units exceeding 3:1. The 2004:2003 ratio averaged over all ten units was 4.9:1.‍?Average tree diameter, tree age, tree density, and elevation for the ten management units indicate that the associated stands are highly susceptible to MPB infestation. Given the abundance of MPB within the management units and concurrence of stand characteristics that favor MPB infestation, these units are all likely to sustain major losses to MPB over the course of this epidemic. Management actions to address the MPB infestation occurring in the Upper Fraser Analysis area are discussed.