2011-10-03_REVISION - C1980007 ‎(2)‎

• Permit No: C1980007
• IBM Index Class Name: REVISION
• Doc Date: 10/3/2011
• Doc Name: Phase II Bond Release Application
• From: Savage & Savage
• To: DRMS
• Type & Sequence: SL4
• Media Type: D
• Archive: No

computer generated random directions (0- 360 In no event were transects allowed to
extend within ten feet of revegetated area boundaries to minimize impacts from "edge effect."
For statistical purposes, each cover transect (comprising 50 data points) served as a sample
unit. Data points recorded the first vertical "hit" on vegetation (above or below the
instrument), soil (bare ground), rock, litter, or cryptogamic crust. Subsequent "hits" on
vegetation (prior to interception of the ground) were also recorded. Cover data were recorded
and reported by individual plant species. The first interception was used to calculate total
vegetation cover values. Additional interceptions were used to calculate relative cover of
individual plant species and lifeforms. The quantitative cover data also provided the basis for
calculation of species composition and relative importance.
2.2.3 Species Composition
Species composition information was derived from quantitative vegetation cover data.
Relative cover information provided a basis for evaluation of the importance of each
encountered plant species and lifeform and for comparison to the final revegetation success
criterion. The tables presenting data summaries for total vegetation cover for each area
sampled also contain the relative cover by species, and a column depicting the numerical
ranking of each species by relative cover within the area.
2.3 SAMPLE NUMBERS /SAMPLE ADEQUACY
For the purposes of this study, total vegetation cover and total herbaceous production
sampling were undertaken to sample adequacy for each sampling unit with a minimum of
fifteen (15) samples. Parameter testing occurred at the one -sided 90% confidence level.
Comparisons between sample mean parameter values and the revegetation success standard
assume that the sample mean value accurately represents the population mean in all cases.
The following formula was used for sample adequacy calculations:
where:
nmin =
nmin = minimum sample size
s = sample standard deviation
t = the Student's t distribution value at the 90% level (one- sided)
d = percent acceptable deviation from the mean (10 %)
Xbar = sample mean
2.4 STATISTICAL ANALYSIS
Mountain Coal Company, LLC West Elk Mine
2011 Reclaimed Areas Vegetation Report
Phase II Bond Release
(t) (s)
(d Xbar)
Statistical analysis for the revegetation success criterion of total vegetation cover is required
if the value of the sample mean from the reclaimed area is less than 90 percent of the value of
the final revegetation success criteria for total vegetation cover. Sampling revealed that the
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