Final answer:
A volcanic eruption in Yellowstone National Park could decrease the grey wolf population due to a subsequent lack of food, as wolves rely on prey whose numbers might also be affected by the disruption of the ecosystem.
Step-by-step explanation:
A volcanic eruption that spews a dense ash cloud in Yellowstone National Park would have significant ecological consequences, including impacting the grey wolf population. This event is most likely to lead to a decreased population due to lack of food. Grey wolves are a keystone species, and their presence influences the behavior of prey such as elk. An ash cloud could disrupt the food web by affecting vegetation and primary consumers, leading to a reduced available prey base for the wolves. Less food means lower carrying capacity for the wolves, and this decreased food availability would not only affect the wolves directly but also has potential cascading effects on the broader ecological community.
Environmental changes like volcanic eruptions can induce immediate and potentially irreversible changes in ecosystems, influencing not just single species but also community interactions and habitat conditions. Over time, the wolf population could potentially adapt or migrate in search of better conditions; however, such an event would not result in stable populations without significant environmental stress and potential population decline first.