Few independent forestry organizations can afford their own genetics research program. In addition, although the USDA Forest Service and some of the largest forest products companies have research staffs, maintaining a strong ongoing research effort in the specialized field of genetics is difficult. Consequently, Tom Adams (Forest Science) notes, an information gap between genetic researchers and tree breeders developed with cutbacks in research funding in the early 1980s. To close that gap, tree breeders in the Pacific Northwest sought assistance from the College of Forestry. As a result, the Pacific Northwest Tree Improvement Research Cooperative (PNWTIRC) was established in July 1983.

Nationwide, most tree improvement activities are conducted through cooperatives, including development of breeding plans, coordination of selection, breeding and testing of parents, and analyzing and interpreting data. A common secondary function is to conduct research supporting the applied breeding efforts. The PNWTIRC, however, differs from the usual university tree improvement cooperative. One major reason is that cooperative applied tree breeding in coastal Oregon and Washington is under the direction of the Northwest Tree Improvement Co-operative, a non-profit association of forest industries. The emphasis of the PNWTIRC is to provide research support for the Northwest Tree Improvement Co-operative and other public and private tree improvement programs in the Northwest.

The goal of the PNWTIRC is to enhance the efficiency of breeding efforts by addressing priority research needs. The selection of specific projects is not always easy, because member organizations differ in their priorities. Nevertheless, active involvement of the membership in project selection and development aids in reaching consensus.

At present, the PNWTIRC's research is focused on two major areas. The first, in which work has been under way for nearly 10 years, is understanding and making use of the genetics of adaptive traits of Douglas-fir. Genetic improvement emphasizes growth and wood quality, but researchers seek to improve these in ways that will not reduce the tree's adaptation. For Douglas-fir, hardiness to cold and drought is essential to the broad use of genetically improved varieties for reforestation. Artificial freeze-testing procedures developed by the PNWTIRC enable breeders to rank Douglas-fir families rapidly and accurately for their relative hardiness to fall and spring frosts. These procedures work well both in seedlings grown in nurseries and in sapling-age (10- to 15-year-old) trees in field tests. In fact, Adams reports, families rank similarly whether they are freeze-tested at the seedling or sapling stages.

Current projects are addressing ways to assess hardiness to summer drought. Again, hardiness at both the seedling and sapling stages is being investigated. Seedlings have been grown in a nursery at the FRL and subjected to three levels of summer watering, from abundant to very little water. Damage to water-conducting tissues and to seedling growth is being measured, and genetic controls on these traits are being evaluated. Drought-hardiness in sapling-age trees is assessed by investigating the impact of past drought years on annual growth rings, as determined by measuring growth rings in wood cores sampled from the trees. It remains to be proven, however, whether growth rings of sapling-age trees are sensitive enough to soil moisture conditions to be useful. Screening procedures for both cold- and drought-hardiness will ultimately be tested by ranking families using these procedures and then evaluating their performance in a variety of field environments.

Associate Director Thimmappa Anekonda (Forest Science) describes the PNWTIRC's second major focus as research directed at improving the efficiency of Douglas-fir seed orchards. In traditional orchards, stems are widely spaced to promote large crowns, and clones are intermixed to promote intermating through wind pollination. Unfortunately, some pollen is carried in from surrounding areas, and the genetic quality of the seed is reduced due to the partial pollination from non-orchard trees (referred to as pollen contamination). As much as 40% to 50% of the seed in wind-pollinated Douglas-fir orchards can be the result of pollen contamination. One recently initiated project, being conducted in collaboration with Steve Strauss (Forest Science), is to develop better methods of assessing levels of pollen contamination using molecular genetic markers.

The PNWTIRC is also investigating orchard technologies for the future. The Òmicro-orchardÓ is a new alternative from New Zealand and Australia, where it is being used by radiata pine breeders. Unlike traditional orchards, micro-orchards entail closer spacing, smaller trees, and more intensive management. Because trees are planted much more densely and are not allowed to grow more than 1-2 meters tall, crowns are easier to reach for culturing and seed collection. Furthermore, planting clones in rows facilitates collection of pollen and artificial pollination, which can dramatically reduce or even eliminate pollen contamination. Artificial pollination can also be used to produce specific crosses of parents for specialized purposes, such as hardiness to particularly stressful sites or specific wood properties. Researchers are not yet certain whether the cost of micro-orchards will be low enough and the seed yield high enough for their use to be feasible for Douglas-fir. However, the ability to eliminate pollen contamination and control mating is a huge potential benefit spurring this research effort.

Many PNWTIRC findings have had great significance for Douglas-fir breeding efforts in the region. For instance, past work on stem form and wood quality traits led to effective, cost-efficient methods of measurement and emphasized the importance of including ÒqualityÓ traits when selecting for orchard parents. Another example is the PNWTIRC's work on early testing, which has shown that seedling measurements can be effectively used to identify those families with the poorest potential for stem growth, so that the number of families tested in expensive field trials can be reduced. It is also likely that seedling tests will prove valuable for assessing the hardiness of families to cold and drought; the results of these tests can be used in deciding which families to plant on sites particularly susceptible to such stresses.