PERMFILE118814

• Permit No: C1981033
• IBM Index Class Name: Permit File
• Doc Date: 12/11/2001
• Section_Exhibit Name: Exhibit 25 Bear 1 & 2 Reclamation Plan
• Media Type: D
• Archive: No

•
r1
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Comparison of relative cover values calculated using fu•st hit data vercuc multiple hit data at Bear
Mines 1 & 2.
A complete comparison of first hit versus multiple hit derived relative cover values
involves answering the following three questions.
1. Was the number of extra vegetation hits (2nd, 3rd,...) large relative to the
number of first hits?
The table below lists the total number of herbaceous hits recorded during sampling in 1991
and 1992. [n 1991, 14 transects resulted in 287 total vegetation ocular interceptions ("hits"), and
15 were extra hits. 5.2 `Y of all hits, or an extra 1.1 hits per transect, were observed beyond first
hits. Extra hits increased in 1992 (probably due to an increase in precipitation, and a probable
increase in vertical vegetation structure) to 13.5 and 3.1 extra hits per transect. Thus, most hits
were first hits, which is to be expected as this herb dominated community's vertical structure is
simple. More extra hits would be expected to be recorded in more complex vegetation. For
example, in the North Thompson Creek extended reference area (see North Thomp,5on Creek
Mine Site: Permit Number C-81-025. 1992 Vegetation ReQort- September- 1992), of the 723 total
vegetation hits noted from the mixed shrub community, 207 (28.6%, 9.4 extra hits per transect)
were hits beyond first hits.
Stratification of vegetative hits recorded at Bear Mines 1 & 2, 1991 and 1992, and North
Thompson Creek reference area in 1992.
Absolute number of hits
Number of transecu
Total veg. hits
Fust hits
Extra hits
Average hits per transect
Total veg. hits
First hits
Extra hits
Relative number of hits
First hits
Extra hits
Bear '91 Bear '92 NTC '92
14 19 22
287 437 723
272 378 516
15 59 207
20.5 23.0 32.9
19.4 19.9 23.5
1.1 3.1 9.4
94.8%
5.2%
86.5 %
13.5%
71.4%
28.6%
2. Was the correlation between first hit relative cover and multiple hit relative cover
significantly different from 1.00?
Using each plant species' fast hit relative cover as the independent variable and each plant
species' multiple hit relative cover as the dependent variable, regression analysis was carried out
for both 1991 and 1992 Bear data. Actual graphs showing the spread of points around the
regression line follow the text. The Pearson correlation coefficient (r) for the 1991 and 1992 data
was 0.9996 and 0.9990 respectively. As the graphs show, the relationship between the two types
of data is extremely close. Because the correlation is significant, one can predict with a high
degree of accuracy the relative cover derived from multiple hit data from that calculated using
B-1