AP Environmental Science Exam Review - Units 1-3

A set of high-yield vocabulary flashcards covering the key concepts from Units 1, 2, and 3 of the AP Environmental Science curriculum, including Ecosystems, Biodiversity, and Populations.

Primary producers

Organisms that convert solar energy into chemical energy via photosynthesis.

Gross Primary Productivity (GPP)

The total amount of energy produced by producers through photosynthesis.

Net Primary Productivity (NPP)

The total amount of energy produced by producers minus the energy used for respiration ($NPP = GPP - \text{respiration}$).

Limiting nutrients

Nutrients, often nitrogen or phosphorus, that restrict the productivity of an ecosystem.

10% rule

The principle that only approximately $10 \text{\%}$ of energy transfers from one trophic level to the next (e.g., $10,000\text{\,J} \rightarrow 1,000\text{\,J} \rightarrow 100\text{\,J}$).

Keystone species

Species that have disproportionately large ecological impacts on their ecosystem.

Indicator species

Species that reflect specific environmental conditions, such as amphibians.

Ecosystem services

The benefits provided by ecosystems, categorized into provisioning, regulating, cultural, and supporting services.

Biomes

Geographic regions defined by their specific temperature and precipitation patterns.

Tundra

A biome characterized by the presence of permafrost.

Photic zone

The layer of an aquatic biome that receives sunlight.

Nitrogen fixation

The process within the nitrogen cycle that converts $N_2$ into ammonia ($NH_3$).

Species richness

The number of different species present in a community.

Species evenness

The relative abundance of each specific species in a community.

Island biogeography

A field of study identifying how biodiversity depends on island size and distance from the mainland.

Endemic species

Species that are restricted to specific locations and are only found in those specialized areas.

Generalists

Species with broad niches that can survive under various conditions.

Specialists

Species with narrow niches that require specific conditions to survive.

Ecological tolerance

The range of environmental conditions that a species can endure.

Primary succession

Ecological succession that occurs in an area without soil, such as a new volcanic island.

Secondary succession

Ecological succession that occurs in an area where soil is already present, such as after a forest fire.

Pioneer species

The first species to colonize an area after a disturbance.

Invasive species

Non-native species that often lack natural predators and cause ecological harm.

Resilience

The ability of a habitat to recover after a disturbance.

Resistance

The ability of a habitat to remain unchanged during a disturbance.

Fundamental niche

The potential range of environmental conditions and resources an organism can occupy.

Realized niche

The actual range of conditions and resources where organisms exist.

Competitive exclusion

The principle stating that two species cannot occupy the same niche long-term.

Carrying capacity (K)

The maximum sustainable population size an area can support.

Exponential growth

Population growth that forms a J-shaped curve.

Logistic growth

Population growth that forms an S-shaped curve.

Density-dependent factors

Factors like disease and competition that affect populations based on their density.

Density-independent factors

Factors like weather and disasters that affect populations regardless of their size.

r-selected species

Species that produce many offspring with low survival rates.

K-selected species

Species that produce fewer offspring with higher survival rates.

Total fertility rate (TFR)

The average number of children born per woman in a population.

Replacement rate

The fertility rate required to maintain a stable population, which is approximately $2.1$ in developed countries.