AP Environmental Science - Unit 1: Ecosystems & Energy Flow

Ecosystem

A community of living (biotic) organisms interacting with non-living (abiotic) components of their environment as a system.

Community

All the different populations of species living in a specific area.

Population

A group of individuals of the same species living in the same area at the same time.

Symbiosis

A close, long-term biological interaction between two different organisms.

Mutualism (+/+)

A symbiotic relationship where both species benefit.

Commensalism (+/0)

A symbiotic relationship where one species benefits and the other is unaffected.

Parasitism (+/-)

A symbiotic relationship where one organism benefits at the expense of another.

Intraspecific Competition

Competition between members of the same species.

Interspecific Competition

Competition between members of different species.

Competitive Exclusion Principle

When two species compete for the exact same resource, one typically outcompetes the other.

Resource Partitioning

Using the same resource in different ways, places, or times to reduce direct competition.

Temporal Partitioning

Using resources at different times to reduce competition.

Spatial Partitioning

Using different areas of a shared habitat to reduce competition.

Morphological Partitioning

Evolving different body shapes or sizes to use different parts of a resource.

Biomes

Large distinct terrestrial regions having similar climate, soil, plants, and animals.

Temperature (Influence on Biomes)

Average and seasonal range affecting biome distribution.

Precipitation (Influence on Biomes)

Total annual and seasonal distribution affecting biome distribution.

Latitude/Altitude

Distance from equator or height above sea level that influences biomes.

Tropical Rainforest Characteristics

High biodiversity, rapid decomposition, hot and wet year-round.

Temperate Deciduous Forest Characteristics

Broadleaf trees that lose leaves, seasonal temps, moderate rain.

Taiga Characteristics

Coniferous evergreen trees, long cold winters, and short summers.

Temperate Grassland Characteristics

Grasses dominate, few trees, adapted to fire and grazing.

Oligotrophic Tundra Characteristics

Permafrost, lichen, moss, no trees, freezing cold, very dry.

Desert Characteristics

Succulents like cacti, variable temperature, low rainfall.

Savanna Characteristics

Tropical grassland with scattered trees, warm year-round, wet/dry seasons.

Chaparral Characteristics

Spiny shrubs, adapted to fire, hot dry summers, mild wet winters.

Climatogram

A graph mapping average monthly temperature and precipitation.

Freshwater Biomes

Biomes categorized by flowing (lotic) or standing (lentic) water.

Streams and Rivers

Flowing bodies of water with varying oxygen levels.

Lakes and Ponds Zones

Defined by light penetration: Littoral, Limnetic, Profundal, Benthic.

Intertidal Zone

Coastal band between high and low tide where organisms must adapt.

Coral Reefs

Aquatic biome with the highest biodiversity, sensitive to temperature.

Open Ocean (Pelagic)

Covers most of Earth, low productivity per unit area.

Wetlands

Includes marshes, swamps, and bogs; critical for ecological services.

Carbon Cycle Processes

Involves photosynthesis, cellular respiration, decomposition, and combustion.

Photosynthesis

Plants convert CO2 and sunlight into glucose.

Cellular Respiration

Organisms convert glucose back into energy and release CO2.

Nitrogen Cycle Key Steps (FixNAAD)

Nitrogen fixation, nitrification, assimilation, ammonification, denitrification.

Phosphorus Cycle

Distinct feature with no atmospheric component; necessary for ATP and DNA.

Hydrologic Cycle

Cycle powered by the Sun involving evaporation, transpiration, infiltration.

Primary Productivity

The rate at which solar energy is converted into organic compounds.

Net Primary Productivity (NPP)

The amount of energy available for consumers after plant respiration.

Trophic Levels

Levels in an ecosystem defined by energy flow: Producers, Primary, Secondary, Tertiary Consumers.

10% Rule

Only about 10% of energy is passed to the next trophic level.

Food Chain

A linear path of energy flow in an ecosystem.

Food Web

A complex network of interconnected food chains.

Trophic Cascade

Effects caused by removing a keystone species in a food web.

Matter vs. Energy

Matter cycles while energy flows through ecosystems.