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of these two groups is nearly equal. This indicates that the weed • population consisted of numerous, very small plants. The most abundant weed species was prostrate knotweed (Polygonum aviculare), which oc- curred at densities up to 200 plants/.Sm2. Average planted species production showed an increase from 5.lgm/.5m in 1978 to 13.5 gm/.5m2 in 1979; weed production increased slightly from 13.1 to 14.7 gm/.5m2 be- tween the two years. These data suggest that planted species are capa- ble of making gains in production in the face of weed competition. Maximum planted species production (42.5gm/.5m2) was recorded for 4DSXN; least production (0) was recorded for 4DSHS, 4BEMS, 4BCHS, and 2BCtiS. These data indicate a nearly complete failure for the mesic mixture on these south aspect treatments. Average cover for the mesic mixture over all treatments ranged from 7.3X in May to 6.4°,~ in September (Table 3.4-1). This range shows little change from October 1978 (8.4X). Average mesic mixture density was 11.3 plants/.5m2; 1978 density was 155.7 plants/.5m2, indicating very high seedling mortality between years. This high mortality is attributed to an extended draught during the summer of 1978 (ERT 1979). Average annual production for mesic mixture species was 8.3gm/.5m2; 1978 produc- ' tion vas 4.6gm/.5m2. These data indicate a slight increase in produc- tion over time despite a substantial decline in seedling density. Of the mesic species planted, orchard grass, perennial rye, smooth brome, and ladino clover showed similar survival rates (2-4 plants/.5m or less than one plant/square foot) when measured is 1979 (Table 3.4-2). Tall fescue was nearly absent. Of the species tested, smooth brome and ladino clover showed increases in cover between Hay and September. In nearly all cases, maximum survival and growth was recorded on north- facing slopes aspects. Ladino clover contributed maximum cover (20X) on the level refuse plots. Average cover for the xeric mixture over all treatments ranged from 12.2X in May to 8.4°,( in September (Table 3.4-1). These values are similar to the 1978 cover values (Maq 11.3X; October 5.1X)• Average density was 19.8 plants/.5m2; 1978 density was 63.8 plants/.5m2. $eric species showed.a much higher survival rate than mesic species. Average ~~ annual production for the xeric mixture increased from S.Sgm in 1978 to 18.5gm/.5m in 1979. 26