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Comparison of Risk/Hazard Rating Systems for Mountain Pine Beetle in Black Hills Ponderosa Pine Forests
(1997)
  • Judith E Pasek, USDA Forest Service
  • Thomas M Juntti, USDA Forest Service
Abstract
Risk/hazard rating methods for mountain pine beetle (MPB) in ponderosa pine stands were compared, based upon number of stands and acres that rated as low, medium or high risk/hazard, for four recent project areas on the Black Hills National Forest. Methods compared were the (1) Stevens model described by Stevens et al. (1980) except that the basal area threshold for high susceptibility was reduced from 150 to 120 based upon results of Schmid and Mata (1992), (2) FORPLAN model used in the Draft Revised Black Hills National Forest Plan (same as Stevens model except for assumption of only one-storied stand structure), (3) PONBUG model for the Black Hills National Forest (same as Stevens model except that data for trees [greater than or equal to] 1 inch diameter at breast height (DBH) were used rather than [greater than or equal to] 5 inched DBH), (4) Schmid model described by Schmid et al. (1994) with assumptions added to extend it to stands with quadratic mean diameter (QMD) of < 7 inches and > 13 inches, and (5) Schmid 5 model (same as Schmid model but recalculated using data for trees [greater than or equal to] 5 inches DBH rather than [greater than or equal to] 1 inch DBH).

Considerable differences are evident in results of the five methods. Differences in model assumptions, design, and data parameters affected MPB risk/hazard rating outcomes. The analyses of model differences presented in this report cannot identify which is closest to correct as related to MPB behavior in field settings.
Disciplines
Publication Date
August, 1997
Citation Information
Judith E Pasek and Thomas M Juntti. "Comparison of Risk/Hazard Rating Systems for Mountain Pine Beetle in Black Hills Ponderosa Pine Forests" (1997)
Available at: http://works.bepress.com/judith_pasek/29/