The effects of hazardous fuel reduction treatments in the wildland urban interface on the activity of bark beetles infesting ponderosa pine

摘要: (Please note, this is an abstract only) Selective logging, fire suppression, forest succession, and climatic changes have resulted in high hazards over large areas of the western United States. Federal state hazardous fuel reduction programs increased accordingly to reduce risk, extent severity these events, particularly wildland urban interface. In study, we examined effect mechanical treatments on activity conifer-infesting bark beetles ponderosa pine, (Pinus Dougl ex. Laws.), stands. Treatments were applied both late spring (April-May) summer (August-September) included: (1) thinned biomass chipped randomly dispersed within each plot, (2) chipped, dispersed, raked 2 m from base residual trees (3) lopand- scattered (4) untreated control. The mean percentage attacked by ranged 2.0% (untreated control) 30.2% (plots with all chipped). A three-fold increase proportion was observed versus lop-and-scattered plots. Higher levels beetle associated treatments, which general corresponded periods peak adult activity. Raking chips away did not significantly affect attack rates. Several species present including roundheaded pine beetle, (Dendroctonus adjunctus Blandford), (D. brevicomis LeConte), mountain ponderosae Hopkins), red turpentine valens Arizona fivespined ips, (Ips lecontei Swaine), California (I. paraconfusus Lanier), engraver, pini (Say)). Dendroctonus most common infesting trees. significant correlation found between number per plot stems D. attacks. At present, no difference tree mortality exists among treatments.