Question

question 1 of 10
a slow - moving stream has many plants growing in it. changes to the climate make the water in the stream move much faster. what is the most likely effect of this change?
a. the stream will become more stagnant.
b. the stream will turn into a bog.
c. the stream will become more productive.
d. the stream will have fewer plants growing.

Explanation:

Step1: Analyze the relationship between stream speed and plant growth

Plants in a slow - moving stream rely on the slower water flow for nutrients, sediment deposition (which can be a source of nutrients and a place to anchor), and a more stable environment.

Step2: Consider the impact of faster water flow

When the water moves much faster:

• Erosion increases. Faster - moving water can erode the stream bed and banks more vigorously. This can remove the sediment that plants use for anchoring. For example, small aquatic plants that are rooted in the stream bottom may be uprooted as the sediment is washed away.
• Nutrient retention is reduced. Slower - moving water allows more time for nutrients (such as dissolved organic matter, minerals from the surrounding soil that leach into the water) to interact with the plants. Faster flow means these nutrients are carried away more quickly, so plants have less access to them.
• Physical damage to plants. The force of the faster - moving water can physically damage the plants. Aquatic plants have a certain tolerance to water movement, but beyond a threshold (when the flow becomes much faster), their stems can be bent, broken, or they can be dislodged from their positions in the stream.

So, overall, the stream will have fewer plants growing.

Answer:

D. The stream will have fewer plants growing.