20. The elk and deer population soared in Yellowstone National Park in the early 1900s when wolves were completely removed from the park. What happened to grasslands in Yellowstone after wolves were reintroduced in 1995?
Answer: C
Grasslands flourished because of lower populations of deer and elk eating the grass
The reintroduction of wolves in 1995 led to a decline in the populations of deer and elk, which in turn allowed grasslands in Yellowstone to thrive. With fewer herbivores consuming the vegetation, the grasses were able to grow and regenerate effectively.
A) Grasslands became barren due to the increase in small burrowing ground animals
This option is incorrect because the grasslands did not become barren; instead, they flourished due to the reduction in deer and elk populations. While small burrowing animals may impact the ecosystem, the primary effect of wolf reintroduction was the recovery of grasslands.
B) Grasslands became stands of trees because of the decline in deer and elk populations
This option is misleading as it suggests that grasslands transformed into forests. While some areas may see increased tree growth due to reduced herbivory, the primary outcome was an increase in grassland health and biodiversity rather than a complete change to tree stands.
C) Grasslands flourished because of lower populations of deer and elk eating the grass
This option is correct. The reduction in deer and elk populations allowed for the recovery of grasslands, enabling grasses to grow more vigorously without the pressure of overgrazing. This ecological change highlights the significant role predators play in maintaining healthy ecosystems.
D) Grasslands became sparser because wolves were walking on the grasses
This option is incorrect as it attributes the decline of grasslands to the presence of wolves. While wolves may traverse the landscape, their presence primarily serves to regulate herbivore populations, which is beneficial for grassland health rather than detrimental.
Conclusion
The evidence clearly illustrates that the reintroduction of wolves led to a healthier ecosystem characterized by flourishing grasslands due to the decreased grazing pressure from deer and elk. All other options fail to accurately represent the ecological dynamics at play following the wolves' return, underscoring the importance of predators in ecosystem management.