The Average NPP Value for a Region of Ocean Is

question 219

Multiple Choice

The average NPP value for a region of ocean is 100 g C/m²/year.The average NPP for a tropical forest is 2,200 g C/m²/year.Yet oceans account for 24 percent of the world's total NPP, while tropical forests account for only 22 percent.What factor accounts for the discrepancy in average value and percentage of NPP for these two ecosystems?

• A) Area covered by oceans is much greater than area covered by tropical forests.
• B) Ocean NPP measurements are much less accurate than land measurements.
• C) Ocean NPP is measured by depth instead of area, which dilutes the measurements.
• D) Ocean NPP measurements have respiration subtracted; land measurements do not.
• E) The two measurements were made at very different latitudes.

---

Definitions:

Dependent Variable

The variable in an experiment or model that is expected to change in response to changes in the independent variable.

Independent Variable

The variable in an experiment that is manipulated or changed by the researcher to observe its effects on the dependent variable.

SSE

Stands for Sum of Squared Errors, a measure used in statistics to indicate the difference between the observed and predicted values.

Coefficient Of Determination

A statistical measure, often denoted as R^2, that illustrates the proportion of variance for a dependent variable that's explained by an independent variable or variables in a regression model.