Laserfiche WebLink
• Samolinp Year Stems /acre <br />1985 378 <br />1987 300 <br />1988 314 <br />1989 288 <br />1990 281 <br />1991 228 <br />1992 157 <br />1993 253 <br />Although these data were collected from different areas during these years, and the numbers are <br />thus not strictly comparable, the trend of decreasing, or at least not increasing, shrub density <br />through 1992 is probably real and may be related to competition from the heavy herbaceous <br />growth chat comprises the high production discussed above. It may also be related to effects of <br />the on-going drought from the period of 1988 through 1990. It would appear from climatic <br />data (Figures 7 through 10), that, although the drought ended in 1990, the period of 1991 to <br />• early 1992 was only moderate in terms of total moisture. The late 1992 and 1993 data show <br />relatively abundant moisture for the first time since 1987. The overall averages were 'dragged <br />down' by fhe very low densities observed in the youngest reclamation areas in 1992 and 1993. <br />Nonetheless, it would appear that an increase in shrub density occurred between 1992 and <br />1993. <br />In the Wadge Pasture, shrub densities in 1988 through 1993 were 320, 476, 408, 288, 344, <br />and 356 stems per acre, respectively. The apparent substantial increase in density in 1989 <br />was partially lost by 1990, and, by 1991, a substantial decrease was encountered, yet in 1992 <br />an increase was measured. In 1991, seedlings were encountered in the amounts of about t to 7 <br />percent of total density in the reclaimed areas; while nowhere near 1989 levels, the presence <br />of seedlings may reflect a response to greater moisture in 1991; this may be responsible for <br />the increase in density observed in 1992 which was maintained in 1993. The slight increase in <br />1993 was mainly accounted for in an increase in mountain snowberry of approximately 30 <br />stems per acre, and 4 stems per acre of chokecherry. The degree to which variations in the <br />chance placement of sample points has affected these averages over the years is not known, but <br />within the Wadge Pasture, there are areas of local abundance or scarcity. Random variation in <br /> <br />28 <br />