AP Environmental Science Unit 1: The Living World: Ecosystems

A scientist measures the amount of carbon dioxide fixed by phytoplankton in a lake over one year and reports 500 g C/m²/yr. This figure represents the lake's:

Which biome has the highest net primary productivity per unit area?

Which of the following is an example of a regulating ecosystem service?

In the carbon cycle, which human activity has contributed most to increased atmospheric CO₂ concentrations since the Industrial Revolution?

A food chain shows: phytoplankton → zooplankton → small fish → tuna. If phytoplankton store 100,000 kcal of energy, approximately how many kcal are available at the tuna level (assuming 10% efficiency at each step)?

During the nitrogen cycle, which process converts nitrate (NO₃⁻) in waterlogged soils back into atmospheric nitrogen gas (N₂)?

The phosphorus cycle differs from the carbon and nitrogen cycles primarily because phosphorus:

Deforestation of a watershed causes increased sediment runoff into a nearby river. Which biogeochemical cycle is MOST directly disrupted by the loss of plant root systems holding the soil?

In a grassland ecosystem, grass produces 8,000 kcal/m²/yr. Grasshoppers consume the grass and assimilate 800 kcal/m²/yr. What is the ecological efficiency of energy transfer from grass to grasshoppers?

A coral reef ecosystem provides habitat for hundreds of fish species and protects coastlines from wave erosion. Which pair of ecosystem service categories does this represent?

A forest has GPP of 2,000 g C/m²/yr and plant respiration of 800 g C/m²/yr. What is the NPP available to consumers?

In a food web, a hawk eats rabbits, which eat grass. If a disease eliminated 50% of the rabbit population, which of the following is the most likely short-term outcome?