Growth of Ponderosa Pine Stands in Relation to Mountain Pine Beetle Susceptibility

Growth of Ponderosa Pine Stands in Relation to Mountain Pine Beetle Susceptibility PDF

Author:

Publisher:

Published: 1999

Total Pages: 20

ISBN-13:

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Ten-year diameter and basal area growth were determined for partially cut stands at 4 locations. Average diameters in the partially cut plots generally increased by 1 inch or more, while average diameter in the uncut controls increased by 0.9 inches or less. Individual tree growth is discussed in relation to potential susceptibility to mountain pine beetle infestation. Basal area increases ranged from 0.9 to 1.9 ft2/acre/ yr in partially cut plots, while basal area increases in the control plots ranged from 0.4 to 1.4 ft2/acre/yr. Endemic mountain pine beetle infestations and snow breakage accounted for most of the mortality on the plots, which decreased the residual basal area and basal area growth. Increases in basal area are used to estimate the length of time required for various stand densities to reach the susceptibility thresholds for mountain pine beetle infestation. Stand marking may influence future susceptibility to beetle infestations.

Mountain Pine Beetle-killed Trees as Snags in Black Hills Ponderosa Pine Stands

Mountain Pine Beetle-killed Trees as Snags in Black Hills Ponderosa Pine Stands PDF

Author: J. M. Schmid

Publisher:

Published: 2009

Total Pages: 8

ISBN-13:

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Mountain pine beetle-killed ponderosa pine trees in three stands of different stocking levels near Bear Mountain in the Black Hills National Forest were surveyed over a 5-year period to determine how long they persisted as unbroken snags. Rate of breakage varied during the first 5 years after MPB infestation: only one tree broke during the first 2 years in the three stands; breakage increased during the third year; the highest percentage of snags broke during the fourth year; and 10% to 14% broke in the fifth year. Cumulatively, snag breakage was 76%, 91%, and 95% in a GSL 80/90, GSL 100/110, and unmanaged stand, respectively. On average, 56% of the snags broke below 25 ft. The rate and height of breakage in mountain pine beetle-killed trees indicates that they are unlikely to persist as suitable snags for more than 5 to 10 years after infestation.

Cutting on Mountain Pine Beetle-caused Tree Mortality in Black Hills Ponderosa Pine Stands

Cutting on Mountain Pine Beetle-caused Tree Mortality in Black Hills Ponderosa Pine Stands PDF

Author:

Publisher:

Published: 2007

Total Pages: 19

ISBN-13:

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Ponderosa pine stands were partially cut to various stocking levels at five locations, periodically surveyed, and remeasured during the 20 years after installation. Mean diameter generally increased 2 inches over the 20-year period on most partially cut plots and less than 2 inches on unmanaged controls. Average diameter growth for diameter classes in partially cut plots was generally significantly greater than average diameter growth for the same diameter classes in uncut control plots. Basal area increased 20 to 40 ft2/acre in partially cut plots and 5 to 21 ft2/acre in unmanaged controls at four locations over a 20-year period. Beetle-caused mortality ranged from 0 to 51 percent of the trees in partially cut plots and from 1 to 77 percent of the trees in control plots although mortality was generally 8 percent in partially cut plots. Beetles attacked trees ranging from 8 to 18 inches in partially cut stands and from 7 to 19 inches in unmanaged stands. Beetles did not exclusively attack16-inch diameter trees, so some trees>16 inches may be selected as leave trees. However, if an infestation persisted in a stand, trees in diameter classes>16 had the highest percentage mortality. The effectiveness of partial cutting for minimizing mountain pine beetle-caused mortality is influenced by: residual stocking level, size of the partial cut, amount of time since the area was cut, and proximity of beetle populations. Partial cuts of