1. An ecologist studying desert plants performed the following
experiment. She staked out two identical plots that included a few
sagebrush plants and numerous small annual wildflowers. She found
the same five wildflower species in similar numbers in both plots.
Then she enclosed one of the plots with a fence to keep out
kangaroo rats, the most common herbivores in the area. After two
years, four species of wildflowers were no longer present in the
fenced plot, but one wildflower species had increased dramatically.
The unfenced control plot had not changed significantly in species
composition. Using the concepts discussed in the chapter, what do
you think happened? 2. Imagine that you have been chosen as the
biologist for the design team implementing a self-contained space
station to be assembled in orbit. It will be stocked with the
organisms you choose, creating an ecosystem that will support you
and fiver other people for two years. Describe the main functions
you expect the organisms to perform. List the types of organisms
you would select, and explain why you chose them.