APES Midterm

Symbiosis

Any close relationship between two organisms (e.g., tapeworms in humans).

Mutualism

A form of symbiosis where both organisms benefit (e.g., bees pollinating flowers).

Habitat

A species-specific environment with survival conditions.

Ecosystem

Interaction of living and nonliving components in an area.

Mutualism

(+, +) Bees and flowers.

Predation

(+, -) Cheetah hunting gazelle.

Commensalism

(+, 0) Birds nesting in trees.

Competition

(-, -) Species competing for resources.

Biome

A region sharing a consistent temperature and precipitation pattern (e.g., Tropical Rainforest).

Tundra

A low precipitation biome characterized by cold temperatures.

Desert Adaptation - Cactus

Stores water and withstands high heat with minimal rainfall.

Warming Climate Impact on Tundra

Shrinks as treelines advance due to warming.

Estuary

Where freshwater meets saltwater; contains brackish water.

Wetlands Ecosystem Services

Habitat for wildlife and floodwater storage.

Nitrogen Fixation

Converts atmospheric nitrogen into usable forms (ammonia, nitrate) via bacteria or lightning.

Ammonification

Organic nitrogen converted to ammonia.

Nitrification

Conversion of ammonia to nitrite, then nitrate.

Denitrification

Conversion of nitrate to atmospheric N₂.

Phosphorus Cycle Limitation

The slow pace of this cycle limits plant growth due to insufficient (nutrient) in soil.

Hydrologic Cycle Energy Source

Driven by the Sun.

Primary Productivity

Rate of photosynthesis; calculated as NPP = GPP - RL.

Trophic Level - Primary Producer

8,000 kcal.

Trophic Level - Primary Consumer

starting at 8000kcal and ends at 800 kcal.

Trophic Level - Secondary Consumer

starts at 8000 kcal end at 80 kcal.

Trophic Level - Tertiary Consumer

primary producer starts at 8000 kcal, then what trophic level is getting 8 kcal.

Food Web Arrows

Represent energy transfer in ecosystems.

Genetic Diversity

Variety of genes in a species (e.g., color variation in beetles).

Species Richness

Number of species in an ecosystem.

Ecosystem Diversity

Variety of ecosystems in an area.

Provisioning Services

Resources obtained from ecosystems (e.g., fish from oceans).

Supporting Services

Services necessary for the production of all other ecosystem services (e.g., nutrient cycling).

Regulating Services

Services that regulate ecosystem processes (e.g., climate regulation).

Cultural Services

Non-material benefits from ecosystems (e.g., recreation such as birdwatching).

Island Biogeography Rule

Larger islands and closer proximity to the mainland yield higher biodiversity.

Ecological Tolerance - Optimal Range

Ideal conditions for survival of a species.

Ecological Succession - Pioneer Species

First colonizers in an ecosystem (e.g., lichens).

Keystone Species

Species that have a disproportionately large effect on their environment (e.g., wolves).

Indicator Species

Species sensitive to environmental changes (e.g., frogs).