The buildup of salmonid populations in Lake Michigan through annual stockings of hatchery‐reared fish may become limited by the quantity of forage fish, mainly alewives Alosa pseudoharengus, available for food. As a part of a continuing examination of salmonid predator‐prey relations in Lake Michigan, we traced changes in alewife biomass estimated from bottom‐trawl surveys conducted in late October and early November 1967–1978. Weight of adult alewives trawled per 0.5 hectare of bottom (10‐minute drag) at 16 depths along eight transects between 1973 and 1977 formed a skewed distribution: 72 of 464 drags caught no alewives; 89 drags caught less than 1 kg; and 2 drags caught more than 100 kg (maximum 159 kg). Analysis of variance in normalized catch per tow indicated highly significant differences between the main effects of years and depths, and highly significant differences in the interactions of years and transects, years and depths, and transects and depths. Five geographic and depth strata, formed by combining parts of transects wherein mean catch rate did not differ significantly, were the basis for calculating annual estimates of adult alewife biomass (with 90% confidence intervals). Estimated biomass of alewives (±90% confidence limits) in Lake Michigan proper (Green Bay and Grand Traverse Bay excluded) rose gradually from 46,000 (±9,000) t in 1967 to 114,000 (±17,000) t in 1973, declined to 45,000 (±8,000) t in 1977, and rose to 77,000 (±19,000) t in 1978.

The attached volume tables are derived from 69 5 tree measurements obtained in 19 57 and 19 60. Nine general areas were sampled north and south of the Alaska Range and on the Kenai Peninsula. Data were gathered for white spruce (Picea glauca) , quaking aspen (Populus tremuloides) , paper birch (Betula papyrif era) , and balsam poplar (Populus balsamifera) , including black Cottonwood (P. trichocarpa) to a limited extent. Most tree measurements came from randomly located l/50-acre plots within stands comprising at least one acre of the same type and stand-size class. Smalian's formula was used to determine cubic-foot volume of sample trees at least 5.0 inches d.b.h. (diameter breast high). Volume was found between a one-foot stump and a minimum merchantable top of 4. 0 inches inside bark (d.i.b.). Points of measurement were generally at 8.15-foot intervals The International l/4-inch rule and Scribner rule were used to find board-foot volume of sample trees in 16-foot logs. The minimum d.b.h. of sawtimber-size spruce was 9.0 inches; for hardwoods, 11.0 inches. Limits were from a one-foot stump to a top equaling 40 percent of d.b.h. , but not less than 6.0 inches d.i.b. in spruce and 8.0 inches d.i.b. in hardwoods. Initial plottings of volume classes over D^H were linear over most of the range except those for paper birch cubic-foot and balsam poplar 1/ The combined variable reported by Spurr where D = d.b.h. in inches H = total tree height in feet. Spurr, Stephen H. Forest Inventory. 4 76 pp. New York: The Ronald Press Co. 1952. T^ORTHERN FOREST EXPERIMENT STATION U JUNEAU, ALASKA U. S. DEPARTMENT OF AGRICULTURE board-foot. These lines dropped slightly at the upper ends-zones of fewdata. Variability increased with increasing values of D^H for all plottings.

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