Chapter 8 Islands in the Sky
Mountain Life Zones
Merriam’s life-zone concept
Species distribution along elevational gradients
Island Biogeography Theory
Desert mountain tops as islands
Mountains as a source of rivers
Life Zone Concept of C. Hart Merriam summarizes the communities on Southwest mountains. From CP-LUHNA.
1. C. Hart Merriam's Life Zone concept, as simple and erroneous as it was, went far in describing the patterns of communities on desert mountains. Describe Merriam's Life Zones and the major shortcomings of his sweeping tenets.
2. Describe how aspect and soils can blur elevational zonation on a desert mountain.
3. Brown applied island biogeography theory to the species diversity of small mammals on desert mountains in the Great Basin. He found that while there was a correlation between mountain size and species diversity, there was no correlation between remoteness of the mountain and species diversity. a) Briefly explain MacArthur and Wilson's island biogeography theory. b) Brown's results are both in accord and in conflict with the theory. What is the biological explanation for these results?