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• measured on all shrubs in the shrub density sample quadrats. Input to the regression equation was average height. Crown diameter was inferred from cover and density data. The average cover of each individual shrub species was calculated as the total cover in cmZ per ha divided by the number of stems per ha for that species. The square root of that value was taken to be a reasonable estimate of crown diameter in cm, which was then input to the crown diameter regression equation. The regression equations yield estimates c:f oven dry grams of production per individual. Estimates of shrub production in the vegetation types were made by converting grams to pounds and multi- plying by the number of stems of that species per acre. The resulting produc- tion estimates are therefore expressed in pounds per acre. It should be noted that WRD is well aware that researchers elsewhere have v;orked on estimating shrub production and have developed far more complex methods of statistical treatment. However, time and money constraints in this case did not allow such an elaborate program. The estimates we have made are, we believe, accurate enough to satisfy the needs of CMLRD for these data. 2.7 WOODY PLANT DENSITY AND HEIGHT SAMPLING A quadrat system was used for sampling woody plant density. A rectangular quadrat (belt-transectl 1 m by 50 m was used for shrubs, while a rectangular quadrat 5 m by 50 m was used for trees (except in the Mountain Shrubland vege- • tation types. The quadrats were oriented along the cover sampling transect. In the Mountain Shrubland vegetation type, all trees were counted in the affected and reference areas. Tree density was calculated by dividing the total number of trees in the affected and reference areas by their correspond- ing acreages. Shrub heights were taken for each shrub encountered in the quadrats. Average heights are reported for each species. Percent of total shrubs less than 1 foot in height is also reported. 2.8 SAMPLE ADEQUACY Sample adequacies for cover, production, and density were calculated separately for the affected and reference areas in each vegetation type. The sample adequacy formula is as follows: __ t's~ nmin IdAI= where n = minimum sample size min t = t value for 2-tailed test 180% confidence, n-1 degrees of freedom) s = sample standard deviation (n-11 • d = desired detectable change in the mean (10%I x = sample mean -4-