7.30 Biomes, Aquatic Systems & Ecosystem Energy Flow – Review Flashcards

31 question-and-answer flashcards covering terrestrial and aquatic biomes, aquatic processes (upwelling, turnover), ecosystem properties, trophic levels, energy flow, ecological efficiencies, biomagnification, and key steps in the nitrogen cycle.

What two abiotic variables are most often used to distinguish terrestrial biomes on climate diagrams?

Average temperature and annual precipitation

Which terrestrial biome has hot temperatures, abundant year-round rainfall, and the planet’s highest biodiversity?

Tropical rainforest

Which biome is cold, dry, and has the lowest annual precipitation of all terrestrial biomes?

Tundra

What biome type dominates the southeastern United States and is marked by moderate temperature and precipitation?

Temperate deciduous forest

Name the ocean zone that lies between high and low tide and is alternately submerged and exposed.

Intertidal zone

What term describes the nutrient-rich bottom region of a lake or ocean?

Benthic zone

List the three major depth/light zones of the open ocean.

Photic zone, aphotic zone, and abyssal zone

How do lentic and lotic freshwater habitats differ?

Lentic habitats contain standing water (lakes, ponds); lotic habitats involve flowing water (rivers, streams).

What wind-driven process brings cold, nutrient-rich water from the deep to the surface near coasts?

Ocean upwelling

In temperate lakes, during which two seasons does complete water turnover typically occur?

Spring and fall

Define an ecosystem in ecological terms.

All the living organisms plus the abiotic factors interacting within a given area.

Which term describes an ecosystem’s ability to remain unchanged despite disturbances?

Resistance

Which term describes an ecosystem’s capacity to rebound after a disturbance?

Resilience

What trophic level is composed of autotrophs that convert solar energy into chemical energy?

Primary producers

Approximately what percentage of incoming solar energy is captured by primary producers?

About 1 percent

According to the 10 % rule, roughly how much energy moves from one trophic level to the next higher level?

About 10 percent

What happens to the remaining ~90 % of energy during trophic transfers?

It is lost as heat, respiration, or waste.

What word refers to the total dry mass of living material produced by an organism?

Biomass

Differentiate Gross Primary Production (GPP) and Net Primary Production (NPP).

GPP is the total energy fixed by photosynthesis; NPP = GPP – energy lost through producer respiration and represents energy available to consumers.

What is Net Production Efficiency (NPE)?

The fraction of assimilated energy that a consumer converts into new biomass.

Give the formula for Trophic Level Transfer Efficiency (TLTE).

TLTE = (production at current trophic level ÷ production at previous level) × 100 %.

Which terrestrial biome contributes the greatest primary productivity per unit area?

Tropical rainforest

Which aquatic ecosystem supplies the greatest total primary production on Earth?

The open ocean (because of its vast area).

What ecological phenomenon causes pollutants to reach higher concentrations at higher trophic levels?

Biomagnification

What is the largest reservoir of nitrogen on Earth?

The atmosphere (as N₂ gas)

Which bacterial process converts atmospheric N₂ into ammonia (NH₃/NH₄⁺)?

Nitrogen fixation

What is nitrification?

The bacterial conversion of ammonia into nitrites (NO₂⁻) and then nitrates (NO₃⁻).

Define ammonification.

Decomposition process that converts organic nitrogen from dead organisms or waste into ammonia.

Which bacterial process returns nitrogen to the atmosphere as N₂ gas?

Denitrification

During which two seasons is water in a temperate lake strongly stratified rather than mixed?

Summer and winter

What type of ecosystem model uses computer simulations to predict how disturbances will affect energy flow and nutrient cycling?

Simulation model