Question

The ecological succession in the diagram took place over hundreds, possibly thousands of years. During this time, heavy rain fell frequently, rushing water over the land. Which organism played the biggest role in keeping fertile soil from washing away during the early years of succession?

A. grasses
B. mosses and lichens
C. softwood trees
D. hardwood trees

Answer 1

Grasses play the most significant role in preventing soil erosion during early ecological succession, helping stabilize the soil in environments with heavy rain.

Step-by-step explanation:

The organism that played the biggest role in preventing soil erosion during the early years of succession, particularly in an environment with frequent heavy rain, would be grasses (Option A). During early succession, grasses grow and reproduce rapidly, which helps to stabilize soil and prevent it from washing away. This foundational role paves the way for secondary growth, leading to a more complex ecosystem over time.

Mosses and lichens (Option B) are typical pioneer species that contribute to soil formation from rock. However, grasses are more effective at quickly colonizing soil and forming a dense root system that protects the soil against erosion. Thus, while both grasses, mosses, and lichens are crucial in ecological succession, grasses are especially important in the context of soil stabilization in the early stages.