Roots of Stability: Erosion Control Quiz

If a plant grows in the ground, then its roots spread out into the soil; if the roots spread out, then they wrap around soil particles; if they wrap around the particles, then the soil is held in place and cannot be easily moved by wind or water.

If rain falls on bare soil, then it hits with full force; if plants are present, then the leaves catch the raindrops first; if leaves catch the rain, then the water drips down gently; therefore, vegetation reduces the impact and speed of water.

If wind or water moves across the land, then it carries away loose soil; if plants are growing there, then they shield the soil and hold it down; if the soil is held down, then it is not being carried away; therefore, plants prevent erosion.

If wind blows across an open field, then it picks up dry soil; if a row of trees is in the way, then the wind hits the trees and loses its speed; if the wind slows down, then it cannot carry the soil; this line of trees is known as a windbreak.

If wind blows against a bare surface, then it exerts force on the soil; if plants are covering the surface, then the wind hits the plants instead of the soil; if the plants take the hit, then the soil underneath remains undisturbed.

If roots bind soil, then it stays put; if leaves intercept rain, then the impact is softened; if stems slow water, then the water has less power to move dirt; therefore, these three specific actions directly stop erosion.

If there are no roots to anchor the soil on a slope, then the soil is loose; if heavy rain falls, then the soil becomes heavy and saturated with water; if the soil is heavy and loose, then gravity pulls it down the hill all at once.

If grass grows in a thick carpet (sod), then it creates a very dense network of shallow roots; if the roots are dense, then they cover almost every inch of topsoil; therefore, grass is actually one of the best ways to prevent surface erosion.

If a plant takes up water from the soil through its roots, then it moves that water to its leaves; if the water reaches the leaves, then it evaporates into the air; if the plant removes this excess water, then the soil stays at a safer moisture level.

If soil is bare, then it is vulnerable to erosion; if mulch is spread over it, then it provides a protective layer just like leaves; if there is a protective layer, then the wind and rain cannot hit the soil directly.

If water flows over a smooth surface, then it moves fast; if it hits the stems of grass, then friction causes it to lose energy; if it loses energy, then it slows down; if it slows down, then any dirt it was carrying falls back to the ground.

If trees are removed, then the canopy that blocked rain is gone and the roots that held soil die; if the protection and anchors are gone, then wind and water can easily move the soil; therefore, removing trees leads to more erosion.

If a field is plowed and has no plants, then the soil is loose and dry; if the wind blows hard, then there is nothing to block it or hold the soil; therefore, this environment has the least protection and the most erosion.

If a field is left empty between growing seasons, then it is at risk of erosion; if a farmer plants a temporary crop just to protect the soil, then the ground stays covered; this type of protective vegetation is called a cover crop.

If a river flows against its bank, then the moving water wears away the dirt; if willow trees have roots growing into the bank, then the roots act like a cage; if the dirt is in a "cage" of roots, then the river cannot pull it away.

If there is leaf litter, then the ground is cushioned; if there is a canopy, then rain is blocked; if there are deep roots, then the soil is anchored; since a parking lot has none of these, the forest is superior at preventing erosion.

If wind blows, then it can pick up soil; if plants provide a physical barrier (like a windbreak), then the wind cannot reach the soil; therefore, plants protect against both water and wind.

If sand is dry and loose, then the wind moves it easily; if dune grass grows there, then its long roots reach deep into the sand; if the roots hold the sand, then the dune stays in one place instead of blowing away.

If an area has lost its trees and soil is eroding, then new trees need to be added; if humans plant these new trees to restore the environment, then they are performing reforestation to stabilize the land.

If plants stop soil from eroding, then less dirt washes into nearby rivers; if less dirt enters the water, then the water stays clearer and cleaner; therefore, controlling erosion helps keep our water systems healthy.