Treesearch

The association of certain fungi with plant roots results in formation of an organ called a mycorrhiza. There are two principal types of mycorrhizae: those with the fungus confined internally in the root, or endotrophic mycorrhizae, and those with both internal fungus development and an external fungal mantle enveloping the root tips, or ectotrophic mycorrhizae. Intergradation between the two types may also occur.

Regeneration of clear-cut areas is a high-priority problem facing forest managers in the Douglas-fir region. One of the most critical phases of this problem is the establishment of new stands on south-slope sites, where conditions are unfavorable for regeneration.

In the recent past, Port-Orford-cedar was one of the most valuable timber trees in southwestern Oregon and northwestern California. Special characteristics of the wood uniquely fitted it for special uses—battery separators in particular.

Extraordinary growth of introduced tree species—such as Monterey and other pines in Australia, New Zealand, and South Africa, and Sitka spruce, Douglas-fir, and grand fir in Great Britain—has lent impetus to tests of exotic species. Planting of most exotics in the United States has generally met with poor success. Yet there is always speculation that an introduced species may grow faster than a local one, or perhaps supply a type of wood not readily available. Occasionally, introduced species have been planted on a large scale without scientific evidence of adequate survival,...

Lodgepole pine (Pinus contorta) is a major species in northeastern Oregon. The lodgepole type covers nearly 400,000 acres in the Blue and Wallowa Mountains, and individual trees are scattered over many of the remaining six million forested acres in this area (2). The type blankets large areas in watersheds in a region where spring floods and summer irrigation are vital factors in the economy. It also serves as a cover for game--grouse, snowshoe hares, deer, and elk. And, it is potentially important for lumber, poles, and pulpwood.

Charts in this report can be used to estimate site index for Douglas-fir from stand age and from average total height of dominant and codominant trees. Table 1 and figure 2 in USDA Technical Bulletin 201 have been used for this purpose in the past. However, the table requires time-consuming interpolation and the figure gives only rough approximations.

The increasing commercial importance of red alder (Alnus rubra) in the Pacific Northwest has created a demand for research on this species. Noting the lack of information on growth of alder, the Puget Sound Research Center Advisory Committee established a subcommittee in January 1956 to undertake construction of alder yield tables. Through the cooperative efforts of private and public forest agencies, 437 sample plots of varied sizes were measured in northwestern Oregon, western Washington, and British Columbia.

In terms of general weather, the 1958 fire season will be classed as one of the hottest on record and as having unusually frequent spring and summer lightning storms. It was also unusual in that spring and most of the summer were less rainy in western Washington than in normally dry southwestern Oregon. Thus, until late August, cumulative fire-season rainfall ranged from well below normal in western Washington to considerably above normal in southwestern Oregon.

In the Douglas-fir region, is slash burning ultimately good or bad practice? During the early 1940's whenever a group of foresters, met to discuss management or silviculture of that region, they usually debated this question. Until then they had burned slash in most clear cuttings east of the narrow coastal fog belt as accepted practice. Fire reduced or removed hazardous fuel as required by Oregon and Washington laws. If fire thus sufficiently reduced fuel, State authorities released the landowner from legal liability for maintaining a hazard. According to some foresters, however, slash...

Many sugar pines (Pinus lambertiana) can be saved from damage or premature death by the timely removal of threatening blister rust cankers (Cronartium ribicola).