Question

Throughout most of the world, the weather changes over the course of the seasons. Organisms rely on these seasonal changes in many different ways.
In the Nile River Delta, for example, seasonal rains upriver once caused the delta to flood every fall. The flood waters would replenish the nutrients in the delta’s soil. Today, a series of dams on the Nile River has stopped the floods from occurring. What is the most likely result of the lack of seasonal floods?
A.
The population of wild animals in the delta has decreased because there is less fresh water available.
B.
The soil in the delta is deeper and less erosion occurs.
C.
The soil in the delta is less fertile, causing fewer plants to grow.
D.
The population of wild animals in the delta has increased because there is no longer a threat of flooding.

Answer 1

The correct answer is option C, that is, the soil in the delta is less fertile, causing fewer plants to grow.

On the basis of the studies, it has been found that organic matter gets deposited in concentration on floodplains at the time of flooding. This enhances the fertility of the floodplain soil, making them suitable for growing crops and grazing cattle and sheep.  

Flooding has a prime effect on the organic matter, which gets accumulated on the floodplain from terrestrial sources like shrubs, trees, and grasses. It has been witnessed that by flooding organic substance, mainly leaves discharge huge concentrations of dissolved organic carbon. The flooding increases the dissociation of organic matter on the floodplains usually and the majority of this becomes accessible for use by the plants and animals.  

Answer 2

C.
The soil in the delta is less fertile, causing fewer plants to grow.
The flooding of the Nile caused silt and nutrients to replenished in the soil every year.