Answers to Hone Your Problem-Solving Skills Questions

1. The most leaf pubescence would be expected for the population from the driest site (Death Valley), the least pubescence for the wettest site (Superior), with the amount for Oatman intermediate but probably closer to that for Death Valley, based on the magnitude of annual average rainfall.

2. A quantitative expression of the answers from question 1 should show highest absorption in the plants from the Superior population, lowest absorption in the Death Valley population, and intermediate absorption in the Oatman population. If seasonal acclimatization is occurring, this will be indicated by lower absorption of radiation during the driest part of the year.

3. The results generally support the hypothesis that the Death Valley population has the most pubescence and lowest absorption of solar radiation, the Superior population has the least pubescence and highest absorption of solar radiation, and the Oatman population is intermediate for pubescence and absorption of solar radiation. While acclimatization occurs in all three populations during the drying cycle, the magnitude of the change in leaf absorption of solar radiation is roughly the same for each population.