Laserfiche WebLink
<br /> <br /> <br />1 <br /> <br />1 <br />1 <br /> <br /> <br />LJ <br />1 <br /> <br /> <br />1 <br /> <br />l1 <br />ll <br /> <br /> <br />through 1989, yearling cattle have been provided by a local <br />operator adjacent to the mine area. <br />Revegetation monitoring studies were conducted in the Wadge <br />(grazed) pasture in 1988, 1989, and 1990. In these three <br />years, sample size for cover has varied between 15 and 30 <br />samples, while sample size for production and shrub density has <br />been 50. All sample points were randomly placed in the 303- <br />acre pasture. Production sampling was completed in each year <br />before grazing was initiated. In 1988, total production in the <br />Wadge pasture amounted to 3,049 pounds per acre, with alfalfa <br />production accounting for 1,565 pounds per acre (51.3 percent <br />relative production). In 1990, total production for the <br />pasture was 2,741 pounds per acre with alfalfa production <br />totaling 845 pounds per acre (30.8 percent relative <br />production). Growing season precipitation was higher in 1988 <br />than in 1990, accounting for the higher total production in <br />that year. With a nearly 21 percent drop in the relative <br />production of alfalfa over a three year period, it is apparent <br />that grazing has contributed to attainment of the goal of a <br />reduction in alfalfa in the pasture. Shrub density averaged <br />322 stems per acre in 1988 and by 1990 had increased to over <br />424 stems per acre, a 31.7 percent increase in density over <br />three years. In 1988, the standard deviation for shrub density <br />was much grater than the mean value, whereas in 1990, the <br />standard deviation was much lower than the mean. This <br />indicates that the distribution of shrubs may also be more <br />homogeneous in addition to the increased density. Diversity <br />has improved slightly since grazing was initiated. In 1988, a <br />total of 70 species were documented and this has increased to <br />73 in 1990. Species density, the average number of species per <br />100 ml has also been used as a measure of diversity in <br />reclaimed areas. The number of species identified in 100 ml <br />plots measured at each random cover sample point averaged 19.8 <br />PEABODY COAL COMPANY <br />Wesbm Dlvlsion <br />