2013-02-27_REPORT - C1981028 (12)

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Within Reclamation Area 31, Calamor'ilfa longifolia was dominant, with contributions of 11.60 percent total and 46.20 percent relative cover this growing season. Bronws tectorum contributed 5.80 percent total cover and 18.35 percent relative cover. Three additional species encountered during cover sampling contributed three or more percent relative cover including; Oryzopsis hymenoides providing 1.80 and 9.49 percent total and relative cover, respectively, Agropyron smithii with 2.00 percent total cover (8.86% relative cover), and Schizachyrium scopariuln contributing 1.80 percent total and 6.96 percent relative cover. Vegetative litter (prior years growth and other biologic organic material) comprised 42.20 percent ground cover overall within Reclamation Area 31 this season. Bare soil accounted for 32.00 percent of the ground cover. No rock or cryptogams were encountered during the cover sampling this year. 3.4.2 Herbaceous Production Total herbaceous production within Reclamation Area 31 was 77.5 g /m (691 lb /ac) this year. Perennial grasses accounted for 92.4 percent of production, annual grasses contributed 4.5 percent, perennial fortis provided 2.5 percent, and biennial forbs contributed 0.6 percent of production this season. 3.4.3 Species Composition Cover sampling identified two lifeforms and thirteen species within Reclamation Area 31. The lifeforms included eight species of perennial grass, two annual grass species, two perennial forbs, and one annual forb. Of the species encountered in Reclamation Area 31, nine were native and four were introduced. Perennial species outnumbered annual species by ten to three. Both warm and cool season species contributed to the seasonality of the area. Warm season graminoids outnumbered cool season graminoids by six to four. Two cool season forb species and one warm season forb were encountered. Reclamation Area 31 had five species contributing greater than three percent relative cover this year. The species contributing greater than three percent relative cover included four perennial grasses and one annual grass. These species included Calannnvilfa longifolia (46.20 %), Bromus tectorum (18.35%), Oryzopsis hymenoides (9.49% relative cover), Agropyron smithii (8.86 %), and Schizachyrium scoparium (6.96 %). 3.4 COMPARISON OF RECLAMATION AREAS WITH FINAL RE- VEGETATION SUCCESS CRITERIA Monitoring of revegetated areas at reclaimed coal mines allows for the identification of vegetation community development trends during the extended liability period. This evaluation also assists in decisions regarding yearly grazing, husbandry practices, interseeding, fertilizing, and weed management. Comparison of the reclaimed area values for vegetation cover, herbaceous production, and species composition with the final revegetation success criteria indicates whether revegetation has been successful, or Coors Energy Company Keenesburg Mine Page 14 2012 Revegetation Monitoring Report