In Exercises 16.23– 16.26, conclusions were drawn separately for the effects of age and topography on biodiversity of the forests. Using the separate analyses, it is not possible to determine if the effects of age are consistent for the three types of topography.
a. Write a model relating Fisher’s alpha to the main effects and interaction of age and topography, using annual precipitation as the adjustment for differences in the five regions.
b. If possible, conduct an analysis of the combined effects of age and topography on the biodiversity of the forests with an adjustment for annual precipitation differences across the five regions.
c. If it was not possible to conduct the analysis requested in part (b), modify the factors age and topography in such a manner that an analysis can be conducted.