In the given ecosystem, the mountain lion serves as an apex predator, playing a critical role in controlling the populations of herbivores like deer. If the mountain lion population were to vanish, the most likely early outcome would be an increase in the deer population, as there would be no natural predator to keep their numbers in check. This could lead to overgrazing of willow trees since the deer feed on them.
The increase in the deer population could also have secondary effects on other components of the ecosystem. For instance:
- The rodent population might not immediately increase because rodents could still be preyed upon by other predators, but they might see some benefit if deer are overgrazing and creating more habitat for them.
- With more deer and less predation, willow trees might see increased pressure as the deer consume more of their foliage.
However, the specific choice that fits the question asked is: The deer population will likely increase significantly within a short time, rather than decrease. Therefore, among the responses provided, the correct implication of the loss of mountain lions is that "the willow tree population will increase the next summer." This increase could occur depending on various factors, but initially, the deer population would significantly rise due to the absence of predation.
In many scenarios, the best answer among the options provided would be increased deer populations affecting willow trees negatively and rodent populations tending to increase over time due to less competition for resources. However, keep in mind that the initial question implies outcomes and some parameters may change thereafter.
Just to clarify the given options:
- The stream will become polluted within a few seasons. - This is unlikely to be an immediate outcome of the disappearance of mountain lions.
- The rodent population will increase within a few months. - This could be a secondary effect later on, not directly linked to the initial absence of mountain lions.
- The willow tree population will increase the next summer. - This is also a complex scenario, as the deer population would likely increase, leading to more grazing of willows.
- The deer population will decrease the first winter. - This would not happen; in fact, it would likely increase.
Thus the strongest inference stands to reason in broader ecological interrelations, which shows deer population increasing with cascading implications thereafter, notably regarding over-consumption of willows.