Final answer:
The disturbance described by the large herd of buffalo in a grassland is known as grazing, an example of herbivory important in shaping grassland ecosystems. Overgrazing can impact vegetation structure and diversity, while managed grazing maintains ecological balance.
Step-by-step explanation:
The example of a large herd of buffalo trampling and ingesting much of the vegetation in a grassland that has not been grazed this year is an illustration of a natural disturbance to an ecosystem. This type of disturbance is known as grazing, a form of herbivory where grazers eat parts of several plants without necessarily killing them. American bison, historically referred to as buffalo, play a crucial role in grassland ecosystems by grazing, which can affect plant diversity and the overall landscape of the area. Overgrazing by buffalo and other ungulates can lead to vegetation damage, changed fire regimes, and even affect other species interactions within the ecosystem.
Historically, large herbivores like the bison roamed the Great Plains in massive herds, shaping the ecology of the American prairies. The grazing of bison created 'lawns' of short grass which supported diverse wildlife. However, the pressure from overgrazing can lead to a decline in mammal diversity and promote the encroachment of woody plants into grasslands. Conversely, when grazing is managed well, it can help maintain the balance of grassland ecosystems.