In the described ecosystem, the animal whose absence would have the greatest negative effect is the wolf.
Here's the reasoning:
- Wolves are top predators in this ecosystem, meaning they help control the populations of both deer and foxes, as well as rabbits indirectly.
- If wolves were absent, rabbit populations might explode due to decreased predation, potentially leading to overgrazing and depletion of vegetation.
- Without wolves, deer populations could also increase unchecked, possibly leading to overbrowsing of plants and altering the ecosystem drastically.
- Additionally, without wolves, fox populations may increase, leading to increased competition for rabbits.
In summary, the wolf plays a crucial role in maintaining the balance of the ecosystem, and its absence would have widespread negative effects.