Dr Stephen Malcolm

This assignment is due to be handed in to Dr Malcolm by 2:00 pm on Tuesday, 12 April 2005. It may be handed in at any time before that deadline.

This is a computer-based activity using Excel software (with analysis tools) on any computer located in any of the University computer labs or any of the PCs in room 1106 Wood Hall, or on your own computer at home. This assignment is worth 35 points.

Using the attached data to determine what mortality factors are density dependent. This requires linear regressions and recognition of significance before conclusions can be drawn about the nature of density dependence and the intensity of regulation.

Enter data into an Excel spread sheet and use the linear regression statistical tool to analyze your data. Give references where necessary and printouts of graphs and analyses.

Produce a summary table of your regressions with intercept, slope, r² and P values for regressions of:

6 k-values against log N

6 k-values against K_total.

Note 1: This exercise is relevant to Table 15.3 of Begon, Harper & Townsend (1996) in section 15.3 on “Key-factor analysis” on pages 581-589.

Note 2: The data are available in an Excel spreadsheet in this folder on the CD.

BIOS 615: Ecology

Stephen Malcolm

Density dependence exercise grading criteria

Grading rubric of 4 criteria for score out of 35.

Item	Points	Score
(1) Data spreadsheet calculations	5 points
(2) Regressions (12 graphs)	12 points
(3) Summary table of regressions with slopes & significance	10 points
(4) Discussion of results	8 points
Total	35 points