Boreal mixedwood forests have been commercially logged for conifers, transected by roads and seismic cutlines, and regionally fragmented by agricultural practices.

Most recently, Alberta's public mixedwood forests have been allocated for harvest of trembling aspen for pulp, paper, and oriented strand board products. With relevance to commercial forestry, this report describes the structure and biodiversity of aspen-dominated mixedwood forests of fire origin. The boreal mixedwood forest in Canada extends from southwestern Manitoba, through the central and northern parts of the Prairie Provinces, and into northeastern British Columbia.

A scientist is studying the relationship between x= diameter at breast height (DBH) (in centimeters) of aspen mixedwood forest in Alberta and y= canopy height (in meters). The data are as follows.

x

5.1

7.9

7.1

7.4

15.8

16.4

15.9

13.9

37.0

29.8

45.0

37.0

y

7.1

11.0

9.5

9.2

18.7

19.9

18.8

15.1

25.5

22.0

23.4

26.7

a) What is the average change in canopy height with an increase of one centimeter in DBH?

b) How do you describe the strength of the relationship between y and x?

c ) Find and interpret the coefficient of determination.

d )What percentage of the total variation in y can be explained by the simple linear regression model?

e )Is the simple linear regression model useful for predicting the canopy height of the trees from a given diameter in breast height of the trees? Use the f )p value approach to test the usefulness of the linear regression model at the 0 .05 level of significance.