Treesearch

Wind River Arboretum, located in the Wind River valley near Carson, Wash., was established in 1912 with the planting of a few species of introduced trees on stump land adjacent to the Wind River Nursery. It is the oldest arboretum in the Northwest and ranks among the earliest forestry projects of an experimental nature still in existence in the region. The initial objective was to test the suitability of trees from all parts of the world for forest planting under conditions generally prevailing west of the Cascade Range in Oregon and Washington. This objective was later broadened to...

This fourth annual summary of references is compiled to maintain a systematic recording of publications in the comparatively new field of forest soils research in the Pacific Northwest. It is intended to serve both as a checklist and as a record of development of knowledge.

How much does weathering affect accuracy of fuel-moisture indicator stick readings in different sections of Oregon and Washington? If unpainted lumber is exposed to weather for a few years, its color changes and the grain shows as much erosion as if it were sandblasted. According to the Forest Products Laboratory, chemical as well as physical changes produce these effects. Repeated, unequal swelling and shrinking--caused by wetting and drying at the surface--distorts surface fibers and raises the grain. Sunlight, air, and water on the surface cause chemical changes that produce first brown...

The effect of spacing on stand development is a subject that has been widely discussed. To test spacings ranging from 4x4 feet to 12x12 feet, a Douglas-fir plantation was established in 1925 at the Wind River Experimental Forest near Carson, Wash. This paper reports some results of a remeasurement made in 1957 (table 1) and compares these results with those of previous measurements. A11 measurements have been taken on one 0.4-acre plot in the 12x12 spacing and on three 0. 25-acre plots in each of the other spacings. Height comparisons are based on 30 trees for each spacing.

Timber cruising is frequently made easier through use of local volume tables based on d.b.h. alone. These tables are made by establishing the relation between volume and d.b.h. from measurements (including height) made on sample trees in the stand. The sample-tree measurements are converted to volumes through use of standard volume tables, and a volume-diameter curve is constructed.

This report describes the use of a mobile high-lead yarder to salvage dead and down timber in old-growth stands reserved for future cutting under the staggered-setting system of management.

An instrument known as the spherical densiometer has been found adaptable to permanent-plot estimates of relative canopy closure or density in forest and range ecological studies. The device is more compact and simpler to use than previous ocular-type instruments. Because the instrument has a curved reflecting surface which results in observations from lateral as well as overhead positions, a problem of overlap in readings occurs when adaptation of the densiometer to permanent-plot work is attempted. Some modifications were developed to eliminate this difficulty.

In 1956, The Forest Soils Committee of the Douglas-fir Region endorsed preparation of an annual bibliography dealing with forest soils research in the Pacific Northwest. The first list, published as Research Note No. 130, summarized all forest soils publications pertaining to the region through 1955. A summary of such publications appearing in 1956 was released as Research Note No. 135.

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.