Final answer:
The Tallgrass Prairie's grasses can reach heights of 6 to 9 feet in good conditions, supported by the dense vegetation and fertile soils due to the intricate root systems that replenish the soil with organic material.
Step-by-step explanation:
The Tallgrass Prairie's grasses can reach heights of 6 to 9 feet under optimal conditions. These prairies are characterized by a temperate, semi-arid climate with annual precipitation ranging from 25.4 cm to 88.9 cm (10-35 in). Due to the lower annual precipitation in temperate grasslands, trees are scarce and are typically only found along rivers or streams. Instead, the dominant vegetation includes a variety of grasses that can grow very densely, offering support to populations of grazing animals. The dense vegetation and fertile soils are a result of the extensive network of roots and rhizomes packed within the subsurface of the soil, which anchors the plants and contributes to soil fertility through the decomposition of organic material.