mark the correct statement regarding services

Options

A. the products of ecosystem processes are named as ecosystem services
B. the value of ecosystem services can be easily determined on the basis of function performed
C. out of total cost of various ecosystem services, the nutrient cycling accounts for 50%
D. a healthy forest ecosystem cannot purify air and water

Answer

To determine the correct statement regarding ecosystem services, we will analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understanding Ecosystem Services**:
- Ecosystem services are the benefits that humans derive from ecosystems. These include services like air and water purification, pollination, climate regulation, and nutrient cycling.

2. **Analyzing the First Statement**:
- The first statement claims that the products of ecosystem processes are named ecosystem services.
- This statement is **correct**. Ecosystem services indeed refer to the benefits derived from the natural processes of ecosystems, such as the purification of air and water by forests.

3. **Analyzing the Second Statement**:
- The second statement suggests that the value of ecosystem services can be easily determined based on the function performed.
- This statement is **incorrect**. The value of ecosystem services is influenced by various factors, including the quality of the service, the products provided, and not solely on the function performed.

4. **Analyzing the Third Statement**:
- The third statement claims that nutrient cycling accounts for 50% of the total cost of various ecosystem services.
- This statement is also **incorrect**. Nutrient cycling is a fundamental process that contributes significantly to ecosystem services, and its contribution is generally considered to be more than 50%.

5. **Analyzing the Fourth Statement**:
- The fourth statement asserts that a healthy forest ecosystem cannot purify air and water.
- This statement is **incorrect**. A healthy forest ecosystem plays a crucial role in purifying air and water, making it an essential ecosystem service.

6. **Conclusion**:
- After analyzing all the statements, the only correct statement is the first one: "The products of ecosystem processes are named ecosystem services."

### Final Answer:
The correct statement regarding ecosystem services is: **The products of ecosystem processes are named ecosystem services.**