Appendix  


BOARD OF FORESTRY TECHNICAL RULE ADDENDUM NO. 3
BROOD MATERIAL
A. Hazard Determination
Tree mortality and top killing result when Ips beetle populations reproduce and increase in pine brood material [FN1] and then leave this material and attack pines in the residual stand. Hazard increases with the amount of pine brood material present.
Any suitable breeding material, including pine logs from recently felled trees, represents a hazard as long as it remains on site long enough for the beetles to complete a life cycle in it. During suitable weather, the life cycle may be as short as five weeks. Piling of brood material is more hazardous than leaving it spread-out on the ground.
Timing of brood material production may influence hazard. Hazard is presumed to be highest when pine brood material is produced from February through June and moderate when produced at other times of the year. At no time is hazard presumed to be low. In some parts of the Southern Forest District, hazard is presumed to be high year round, regardless of when the brood material was produced.
Age, size, and species of residual trees influence hazard. Young pole size stands of pine are most susceptible to damage. Tree species other than pine are not damaged by insects that breed in pine brood material. Brood material from tree species other than pine generally does not contribute to the build-up of damaging beetle populations.
Low vigor residual trees are at greatest risk. Historically, drought stressed, suppressed, and overstocked stands have been identified as high risk. Off-site, diseased, damaged, and overmature trees are also at risk.
If damaging insect populations are high, hazard will be greater. High beetle populations have the potential to damage more than just low vigor trees. Chronic pine mortality in the area should be evaluated to determine if high beetle populations are present. An established Zone of Infestation for pine bark beetles implies that conditions are appropriate for the build-up of beetle populations.
Potential for the spread of damaging insects to adjacent ownerships should be considered. The closer the ownership, the greater the risk. Generally, ownerships beyond one quarter of a mile will have little or no risk.
Value of residual trees should be considered. How much loss to residuals is acceptable?
B. Hazard Reduction Treatment Alternatives
Any treatment to reduce hazard should apply to the entire area where a hazard has been determined to exist, including the area where lopping for fire hazard reduction has been used. Treatment alternatives include modification of the brood material so that it is less suitable as a breeding site for beetles or methods to reduce beetle populations that have developed.
Specific Treatment Alternatives applied to pine brood material are as follows:
(1) The following treatments are acceptable provided they are completed before insect broods emerge from infested material. During weather that is suitable for brood development, a five week window is the maximum time that should elapse between creation of brood material and its treatment by one of the following methods: brood material can be removed from the site for processing or disposal; if left on-site, it can be piled and burned, chipped, debarked, treated with an appropriate pesticide, or piled and covered with clear plastic. If brood material is piled and covered, the plastic used must be a minimum of 6 mil thick; piles must be completely sealed by the plastic so that there are no openings to the outside and remain covered for 6 months (or 4 months if at least 2 summer months are included).
(2) The following treatment is acceptable, provided it is completed as soon after brood material creation as is practical, but not later than one week. Lop all branches from the sides and tops of those portions of main stems which are 3 ” or more in diameter. Branches shall be scattered so that stems have maximum exposure to solar radiation. Do not pile brood material. Lopped stems could also be cut into short segments to decrease drying time and further reduce hazard.
(3) Burying brood material will prevent it from being colonized by beetles, but may not prevent emergence of the beetles. Therefore, it must be buried before becoming infested. During suitable weather, brood material must be buried concurrent with its creation.
1 “Suitable” weather depends upon location. In areas that receive snowfall, suitable weather generally exists from April 15-October 15. In other areas, suitable weather exists from March 1-November 30.
HISTORY
1. New Appendix filed 8-5-91; operative 8-5-91 (Register 91, No. 50).
2. Editorial correction inserting inadvertently omitted Appendix A and adding History 1 (Register 96, No. 50).