Question

After dams were built upstream to regulate the flow of water, the trees of some hardwood forests in the Pineywoods ecoregion of Texas died. Which statement gives the most likely connection between the dams and the death of trees?
A.

Dams are used to control flooding, and flooding deposits sediments needed for healthy soil.

B.

Dams generally reduce the flow of water, and this increases water erosion that destroys trees.

C.

Dams block the movement of fish, and many trees depend on fish for nutrients.

D.

Dams divert water to other areas, and organisms in those areas compete with trees for resources.

Please help!

Answer 1

Answer:

A

Explanation:

Answer 2

Answer:

A.  Dams are used to control flooding, and flooding deposits sediments needed for healthy soil.

Explanation:

When a dam stops the course of a river, the fragments of earth and rock carried by the water (the flood) accumulate at the bottom of the river and the reservoir, instead of on the banks of the river. When the water from the reservoir is released, it comes without a flood, and since it is part of the material that enriches the farmland downstream, it deteriorates. In addition, the water leaving the dam carries the flood and continues to erode the land as it digs deeper into the river bed.