What primarily distinguishes grasslands from forests?

Grasslands are primarily distinguished from forests by the amount of rainfall they receive and the corresponding vegetation they support. In grasslands, there is generally insufficient rainfall to support the growth of trees, which leads to a predominance of grasses and other herbaceous plants. This characteristic defines the ecosystem, as the limited moisture results in conditions where grasses can thrive while trees struggle to grow.

The presence of grass instead of trees is essential to the ecology of grasslands, influencing everything from soil properties to the types of animals that inhabit these areas. In contrast, forests typically have higher rainfall and a denser tree canopy, creating an environment that supports a rich diversity of plant and animal life, including large predators. Understanding these distinctions is crucial for studying ecological zones and their respective climates, flora, and fauna.