Final answer:
The drought that kills the grass will likely cause the rabbit population to decrease due to lack of food, which in turn is expected to cause the wolf population to decrease as they depend on rabbits for food.
Step-by-step explanation:
The lack of water killed the grass in the ecosystem, which is a primary source of food for the rabbits. As the grass dies, the rabbit population would most likely decrease due to the scarcity of food. Consequently, as the number of rabbits—a primary food source for the wolves—declines, the wolf population is also likely to decrease. Wolves depend on rabbits and other small animals for sustenance, so with fewer rabbits to hunt, the wolves may suffer from a lack of food, leading to a decrease in their population as well.
This illustrates a chain reaction in ecology, where the impact on one species in the food chain (in this case, the grass) can affect other species that are directly or indirectly dependent on it. This concept is often studied under community ecology and illustrates the interdependence of organisms within an ecosystem.