Treesearch

Multiple regression analyses were used to relate environmental factors to forest regeneration on clearcut and partial cut areas managed by the Bureau of Land Management in the Illinois Valley area southwest of Grants Pass, Oregon. Difficulty of regenerating clearcuttings at elevations between 3,000 and 4,900 feet (914 and 1 494 m) increased with increases in soil coarse fragments, solar radiation, and slash burning. Difficulty of regenerating clearcuttings at elevations between 1,500 and 2,900 feet (457 and 884 m) increased as solar radiation, shrub cover, grass cover, and surface rock...

A simulation model for the development of timber stands in the Pacific Northwest is described. The model grows individual trees of 21 species in a 0.20-hectare (0.08-acre) forest gap. The model provides a means of assimilating existing information, indicates where knowledge is deficient, suggests where the forest system is most sensitive, and provides a first testing ground for hypotheses. Model verification simulations are included for up to 500 years on various sites. Fire, wind, or clearcutting can occur at intervals and intensities specified by users. The model was developed by...

This paper summarizes published reports of deterioration and product recovery studies conducted on dead timber. Decay rates experienced in blowndown timber are presented for western redcedar (Thuja plicata Donn ex D. Don), Douglasfir (Pseudotsuga menziesii (Mirb.) Franco), western hemlock (Tsuga heterophylla (Raf.) Sarg.), and Pacific silver fir (Abies amabilis (Dougl.) ex Forbes). Results from product recovery studies conducted on insect-killed western white pine(Pinus monticola Dougl. ex D. Don), grand fir (Abiesgrandis (Dougl. ex D. Don) Lindl.), Engelmann spruce(Picea engelmannii Parry...

Usable estimates of the mass of live foliage and limbs of sapling and pole-sized ponderosa pine in managed stands in central Oregon can be obtained with equations using the logarithm of diameter as the only independent variable. These equations produce only slightly higher root mean square deviations than equations that include additional independent variables. A better estimate of live foliage mass is produced when distance from breast height to live crown is added. A better estimate of live limb mass is produced with the addition of height. For other components investigated (bole wood...

Provides current information on lumber and plywood production and prices; employment in the forest industries; international trade in logs, lumber, and plywood; volume and average prices of stumpage sold by public agencies; and other related items.

Statistics on forest area, total gross and net,timber volumes, and annual net growth and mortality are presented from the 1975 timber inventory of the Yakutat unit, Alaska. Area of timberland is estimated at 236.3 thousand acres (95.6 thousand ha), net volume of growing stock at 1.1 billion cubic feet (29.9 million m3), and annual net growth and mortality at 5.7 and 1.4 million cubic feet (159.9 and 40.8 thousand m3), respectively.

A multiresource inventory of the Willow block, Susitna River basin inventory unit, was conducted in 1978. Statistics on forest area, timber volumes, and growth and mortality from this inventory are presented. Timberland area is estimated at 230,200 acres and net growing stock volume, mostly birch, at 231.9 million cubic feet. Net annual growth of growing stock is estimated at 7.4 million cubic feet and annual mortality at 742,000 cubic feet.

Statistics on forest area, total gross and net timber volumes, and annual net growth and mortality are presented for the 1971-75 timber inventory of the Tanana unit, Alaska. This report summarizes statistics previously published for the four inventory blocks of the unit: Fairbanks, Kantishna, Upper Tanana, and Wood-Salcha. Timberland area is estimated at 2.19 million acres (888 164 ha), net growing stock volume at 2.27 billion cubic feet (64.36 million m3), and annual net growth and mortality at 61.34 and 6.14 million cubic feet (1.74 and 0.17 million m3), respectively.

A multiresource inventory of the Talkeetna block, Susitna River basin inventory unit, was conducted in 1979. Statistics on forest area, timber volumes, and growth and mortality from this inventory are presented. Timberland area is estimated at 562,105 acres and net growing stock volume, mostly hardwood, at 574.7 million cubic feet. Net annual growth of growing stock is estimated at 13.6 million cubic feet and annual mortality at 2.7 million cubic feet.

Statistics on forest area, total gross and net timber volumes, and annual net growth and mortality are presented from the 1974 timber inventory of the Ketchikan. unit, Alaska. Timberland area is estimated at 1.16 million acres (470 040 ha), net growing stock volume at 6.39 billion cubic feet (181.04 million m3), and annual net growth and mortality at -33.12 million cubic feet and 55.56 million cubic feet (-0.94 and 1.57 million m3), respectively.