- Seymour, Robert S.
University of Maine, School of Forest Resources
To be effective as a budworm-management tool, timber harvesting must be designed to reduce the vulnerability of areas so that they can be withdrawn from insecticidal protection as rapidly as possible. Based on overwhelming scientific and historical evidence which shows that mature (age 50 and older) balsam fir will die in 5-10 years from uncontrolled budworm defoliation, vulnerability can be measure quite simply in terms of the volume of mature fir present - the more fir, the higher the vulnerability. The much-needed analysis of wood supply will suggest how much of this fir volume is needed by industry in a given wood producing region, but will not indicate where (i.e., which specific stands) the wood will come from. This paper summarized the technical aspect of delineating and managing such areas - a process we call "targeted" harvesting, as the actual cutting operations are concentrated on fir as much as possible. Conceptually, the effort needed in Maine can be divided into two basic tasks: (1) construction of an accurate map of forest types of the entire spruce-fir protection district, emphasizing fir abundance, and (2) targeting the harvesting and spraying in optimum fashion on only those areas necessary to provide the required volumes of wood.