2008-03-03_PERMIT FILE - C2006085 ‎(14)‎

• Permit No: C2006085
• IBM Index Class Name: Permit File
• Doc Date: 3/3/2008
• Doc Name: Baseline Vegetation Data by Kent Crofts of IME
• Section_Exhibit Name: Exhibit J
• Media Type: D
• Archive: No

• calculations in Table 2, Northfield Mine Sample Adequacy Calculations, document that the
number of samples required to describe this site at the 90 percent confidence interval was 14.6
transects.
Production. The results of the 50 production transects sampled on this area aze summarized in
Table 13, Disturbed Reference Aria -Production. This table shows that the average total
herbaceous forage production on this site equaled 23.26 g/1/4 m2 or 830 pounds of air dry-dry
forage per acre. Perennial grasses contributed 14.06 g/1/4 m2 or 60.45 percent of the herbaceous
forage produced on this area. Perennial forbs contributed 9.19 g/1/4 m2 or 39.55 percent of the
herbaceous forage production on this area.
The locations of the 50 production transects sampled for this site are shown on Map 3D,
Disturbed Reference Area -Vegetation Transact Location Map. Copies of the individual field
data sheets for the forage production sampling of this site are found in Appendix K -Copies of
Disturbed Reference Area -Production Field Data Sheets. The sample adequacy calculations in
Table 2, Northfield Mine Sample Adequacy Calculations, document that the number of samples
required to describe this site at the 90 percent confidence interval was 47.0 bansects.
Shrab Densiri. The shrub density counts obtained from the 50 belt transacts sampled in this
area are summarized in Table 14, Disturbed Reference Area -Shrub Density. The average shrub
density was determined to equa17.40 shrubs per 100 m2 or 299.5 shrubs per acre. Skunkbush
Sumac and Rubber Rabbitbrush were the most commonly encountered shrubs.
• The locations of the 50 shrub density transacts sampled on the main block for this reclaimed site
are shown on Map 3D, Disturbed Reference Area -Vegetation Transact Location Map. Copies
of the individual field data sheets for the woody plant density sampling of this site are found- in
Appendix L -Copies of Disturbed Reference Area -Shrub Density Field Data Sheets.
Examination of the sample adequacy calculations in Table 2, Northfield Mine Sample Adequacy
Calculations, reveals the number of samples required to describe the shrub density on this azea at
the 90 percent confidence interval was 69.2 try.
Species Diversiri. The perccnt relative composition or cover values in Table 12, Disturbed
Reference Area -Plant Cover, documents that on this Reference Area there were a total of five
perennial plants contributing more than five percent to the total relative cover on this site, Bushy
Eriogonum, Skunkbush Sumac, Blue Grams, Needle and Thread Grass and Sand Dropseed;
which contributed 19.58, 12.30 11.97, 7.77 and 7.61 percent, respectively to the total plant cover
on this site.

Conclusions
At the Northfield Mine, since sample adequacy, at the 90 percent confidence interval, was
achieved for plant cover, herbaceous production and woody plant density sampling on the
Juniper-Grassland Predisturbance Arca and corresponding Juniper-Grassland Reference Area.
Sample adequacy, at the 90 percent confidence interval, was achieved for plant cover and
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