NET PRIMARY PRODUCTIVITY'Y' IN A FRESHWATER POND ECOSYSTEM DURING SPRING Net Primary Productivity to - 10 20 30 40 Depth of Water ( meters )

1.

All organisms in an ecosystem are interrelated by the abiotic and biotic resources they use in the course of their lives:

a. Describe the relationships that exist among a mockingbird, caterpillar, milkweed, and soil in a particular ecosystem. 

b. Discuss TWO examples of the impact of human population growth on abiotic components of the environment. For each example, explain how a change in the abiotic component will impact the biotic component of the biosphere.

2.

Consumers in aquatic ecosystems depend on producers for nutrition.

a. Explain the difference between gross and net primary productivity.

b. Describe a method to determine net and gross primary productivity in a freshwater pond over a 24-hour period. 

In an experiment, net primary productivity was measured, in the early spring, for water samples taken from different depths of a freshwater pond in a temperate deciduous forest.

c. Explain the data presented by the graph, including a description of the relative rates of metabolic processes occurring at different depths of the pond.

d. Describe how the relationship between net primary productivity and depth would be expected to differ if new data were collected in midsummer from the same pond. Explain your prediction.

NET PRIMARY PRODUCTIVITY'Y' IN A FRESHWATERPOND ECOSYSTEM DURING SPRINGNet Primary Productivityto-10 20 30 40Depth of Water ( meters )