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INTEROFFICE MEMORANDUM <br />TO: KI?N'1' UOR4L\bt <br />FROM: JANET' E3INNS <br />SUBJECT: RIMROCK 1 NE 3 V ' 'h; I'A'1'ION SAb1P1.ING DATA, C-1989-074 <br />DATE: 3/19/04 <br />CC: ll~1N HERNANDE%, KIRS'1'IN FISHER, V'1'1~ FILE <br />I have completed the vegetation report for the 2003 vegetation sampling event at the Rimrock Mine. Vegetation <br />sampling was conducted by Kirstin Fisher and Janet Binns of Colorado Division of Minerals and Geology. <br />Sampling was conducted on June 23 and 24, 2003. The June 23, 2003 Rimrock Inspection Report contains <br />details of the Divisions observations. <br />The revegetation success standazds for the Rimrock Mine include: <br />Vegetative Cover: 41% <br />Herbaceous Production: 5141bs/acre (air dry weight) <br />Shrub Density: 0 <br />Species Diversity: At least three perennial grass species, each contributing at least 3%, but <br />not greater than 60% relative cover. At least one of these species will be a <br />warm season grass and at least one shall be a cool season grass. <br />Live vegetative cover measured during the June 2003 vegetation sampling event measured 43.2%. This value is <br />greater than the revegetation standard of 41 %. The reclamation achieved the vegetation cover success standard. <br />Vegetative cover data achieved sample adequacy. <br />Live herbaceous biomass measured 72.9 g/ % MZ quadrat. This value equals 145.8 g/ MZ or 1365 lbs./acre. The <br />herbaceous productivity measured on the mine site exceeded the reclamation standard. Vegetative productivity <br />data was achieved sample adequacy. <br />Twenty-three plant species were encountered in the vegetation cover sampling. Nine species measured greater <br />than 3% and less than 60% relative cover. No species were present at greater than 60% relative cover. Of the <br />Nine species, five species were perennial cool season grasses, three were warm season perennial grasses, and <br />one was a perennial forb. The perennial forb was field bindweed, which is included on the Colorado State <br />Noxious Weed list. Las Animas County considers field bindweed a species recommended for weed control but <br />not mandatory control. The reclaimed plant community achieved the approved species diversity standazd. <br />The Division calculated vegetative cover success with field bindweed removed from the data. Vegetative cover <br />total with cover contributed by field bindweed removed equals 36.13%. This value is less than 90% of the 41% <br />