From Coos Bay to Vancouver Island, researchers from the Hardwood Silviculture Cooperative are examining the growth of red alder. Their main project involves 26 variable-density plantations in western Oregon, Washington, and British Columbia. At each site, cooperators planted large blocks at densities of 100, 230, 525, and 1200 trees per acre. Each block was then divided into plots of about an acre. One was left untreated as a control, two were thinned at different stages of growth, and a fourth was pruned rather than thinned. As Project Leader Dave Hibbs (Forest Science) notes, the sites cover not only a wide geographic range, but also a range of site qualities. From their investigations, researchers seek to discover where it is really appropriate to plant red alder, how fast it will develop, and how land managers can achieve their management goals most effectively.

The oldest of these plantations are about 10 years old. In getting this far, the cooperative has had to overcome a number of problems, the first being to establish a successful plantation. Regeneration from seed in the field proved very difficult, early plantations failed, and basic investigations into alder regeneration were needed. But now the efforts of the cooperative have created a data set on growth of managed red alder that may be second only to the data set for Douglas-fir on the west side of the Cascades. The plantations are finally reaching the age when they are most useful; the results of thinning and other treatments are just becoming apparent. As Hibbs notes, that means cooperators have had 10 years of investment and deferred gratification -- that is a long planning time for many businesses today.

The cooperative came together as a combination of industry and federal and state agency members, each with its own reasons for interest in red alder management. For instance, industry wants to grow alder for high-quality saw logs, while the USDA Forest Service wants to manage red alder to ensure biodiversity. What members have had in common is that they all want to grow red alder to meet their disparate objectives. To do so, they have invested in the cooperative in many ways: they provide the land used for plantations; the crews used for planting, thinning, and making measurements; and the funds that maintain the cooperative itself.

The day-to-day work of the cooperative is carried out by faculty research assistant Alison Bower (Forest Science). She spends 60-70% of her time on the road among the sites, working with crews provided by the cooperators. Because the research is inherently labor-intensive, the help of these crews has been an enormous asset to the cooperative.

In addition to the 26 variable-density stands, the cooperative has four naturally regenerated stands and seven planted mixed-species stands, on which they do related studies. Naturally regenerated stands up to 15 years old and 5 to 10 acres in size were sought as a means of short-cutting some of the growing lag time before meaningful thinning results could be obtained. It came as a surprise to find only four naturally regenerating stands of the right age and size in the entire Pacific Northwest. Once the stands were identified, crews thinned them to specific densities. Although studies in these stands are not as controlled as those on the plantations because the sources of seed and original conditions are unknown, researchers are learning a lot.

The seven mixed plantations of alder and Douglas-fir are new plantations, and the proportions of the two species are varied experimentally. Scientists are looking at the interactions between these species, which are often competitors. One finding is that, in low proportions, alder can benefit the Douglas-fir when soil nitrogen levels are low, because the alder is a nitrogen-fixer. If red alder and Douglas-fir are planted as alternating crops, alder can improve fertility and thus growth of a subsequent plantation of Douglas-fir. Alder may also be a good alternative to conifers in areas infected with laminated root rot. Meanwhile, researchers continue to look for the right balance between species to maintain a beneficial relationship.

Although the cooperative has focused on red alder primarily, work on other hardwoods has begun. A two-year study of bigleaf maple regeneration was completed in 1997. As had happened with red alder, maple growth from seed failed, and nursery stock with large root systems and large-diameter stems did best.