Answer:
The passage traces the chronology of the biological succession of plants to predict that the city will become an oasis fit for human habitation.
Step-by-step explanation:
In this passage, the author discusses how the vegetation of a particular place will change in the future. He tells us that colonizing trees will be replaced by pioneer weeds. We also know that new native oaks and maples will grow in city parks, black locust, autumn olive shrubs, sunflowers, bluestem and white snakeroot will appear and that birds will contribute to the spread of apple trees. In the passage, the author traces the chronology of the succession of plants and in this way proves that the city will become an oasis.