Question

Contribution of services like recreation and nutrient cycling put together constitutes the following percentage of total:

• A. Less than 10%
• B. Accounts for 50%
• C. Less than 20%
• D. 6% each

Hint:

In ecosystem services, soil formation contributes a major share, while recreation and nutrient cycling contribute relatively smaller shares. If each is less than 10%, together they are less than 20%.

Answer 1

The Correct Option is C

Step 1: Understand ecosystem services.
Ecosystem services are the benefits obtained by humans from nature.
These services include soil formation, nutrient cycling, recreation, pollination, oxygen production, climate regulation and purification of air and water.

Step 2: Recall contribution of different ecosystem services.
Among ecosystem services, soil formation contributes a very large share.
Recreation and nutrient cycling contribute smaller shares individually.
Each of these services contributes less than 10% of the total value.

Step 3: Combine recreation and nutrient cycling.
Since recreation contributes less than 10% and nutrient cycling also contributes less than 10%, their combined contribution will be less than 20%.
Mathematically, we can understand it as: \[ \text{Recreation} < 10\% \] and \[ \text{Nutrient cycling} < 10\% \] Therefore, \[ \text{Recreation + Nutrient cycling} < 20\% \]

Step 4: Analyze the options.
Less than 10% is too low for the combined value.
Accounts for 50% is related mainly to soil formation, not recreation and nutrient cycling together.
6% each does not represent the combined percentage asked in the question.
Less than 20% correctly represents their combined contribution.

Step 5: Final conclusion.
Thus, the contribution of recreation and nutrient cycling together is \[ \boxed{\text{Less than 20\%}} \]