AP Enviro Test 1

Individual

A single organism belonging to a specific biological species.

Population

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

Community

All interacting populations of different species occupying a common area.

Ecosystem

A biological community interacting with its nonliving physical and chemical environment.

Biome

A large regional ecosystem categorized by climate patterns, soil traits, and dominant plant communities.

Biotic factor

Any living or once-living component within an ecosystem that influences other organisms.

Abiotic factor

Any nonliving physical or chemical property of an ecosystem, such as temperature, water, or soil nutrients.

Mutualism

An ecological interaction between two species where both organisms benefit ($+/+$).

Commensalism

An ecological interaction where one species benefits while the other is unaffected ($+/0$).

Parasitism

An ecological interaction where one organism benefits at the direct expense of a host organism ($+/-$).

Symbiosis

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

Competition

An interaction where organisms struggle to acquire shared, limited environmental resources.

Predation

An interaction in which one organism captures, kills, and consumes another as an energy source.

True predator

A carnivorous organism that kills and consumes its prey relatively quickly.

Herbivore

A primary consumer that feeds directly on autotrophic photosynthetic organisms.

Parasite

An organism that feeds on a host organism over time, often weakening but usually not killing it immediately.

Parasitoid

An organism whose larvae live inside and slowly consume a host organism, eventually causing its death.

Resource partitioning

An evolutionary strategy where competing species divide a niche to avoid direct competition.

Temporal partitioning

Resource partitioning where competing species utilize the same resource at different times of day or seasons.

Spatial partitioning

Resource partitioning where competing species use different physical habitats or spatial zones.

Morphological partitioning

Resource partitioning driven by evolved structural differences in body shape or feeding organs.

Lichen

A mutualistic composite organism consisting of a fungus paired with photosynthetic algae or cyanobacteria.

Coral-algae mutualism

A relationship where marine coral animals provide structure and $CO_2$ while photosynthetic zooxanthellae provide carbohydrates.

Primary biome determinants

Annual average temperature patterns and annual average precipitation levels.

Latitude impact on climate

Distance from the equator dictates solar radiation intensity, strongly controlling temperature and precipitation patterns.

Tropical biome position

Located near the equator, featuring warm temperatures and minimal seasonal temperature fluctuations.

Temperate biome position

Located between $30^\circ$ and $60^\circ$ latitude, characterized by pronounced seasonal temperature shifts.

Boreal biome position

Located at high latitudes around $60^\circ\text{N}$ and above, characterized by subarctic frigid winters.

Tundra characteristics

A cold, treeless biome with low annual precipitation, low plant growth, and a subsoil permafrost layer.

Tropical rainforest characteristics

A warm, high-precipitation biome with lush canopy diversity, rapid nutrient cycling, and thin, nutrient-poor soil.

Temperate rainforest characteristics

A high-precipitation, ocean-moderated forest biome dominated by large evergreen conifers.

Temperate seasonal forest characteristics

A biome with warm summers, cold winters, broadleaf deciduous trees, and fertile soil from leaf litter decomposition.

Boreal forest (taiga) characteristics

A cold forest biome with evergreen needle-leaf trees, nutrient-poor acidic soil, and slow organic decomposition.

Savanna characteristics

A warm tropical grassland with sparse trees, distinct wet and dry seasons, and periodic fire activity.

Temperate grassland characteristics

A prairie biome with hot summers, harsh winters, deep organic soil, and grasses adapted to frequent fires.

Chaparral characteristics

A coastal shrubland biome with hot, dry summers, mild wet winters, and fire-adapted vegetation.

Desert characteristics

An arid xeric biome receiving under $25\,\text{cm}$ of annual rain, with sparse succulent vegetation.

Xeric condition

An environment characterized by extremely low water availability.

Climatogram

A dual-axis graph displaying a region's monthly average temperature and precipitation over time.

Tropical climatogram profile

Features a nearly flat, constant monthly temperature line throughout the year.

Temperate climatogram profile

Features a clear curved temperature line demonstrating seasonal variation.

Northern Hemisphere climatogram indicator

A temperature curve that bows upward (peak in June–August).

Southern Hemisphere climatogram indicator

A temperature curve that bows downward (peak in December–January).

Tropical rainforest soil status

Nutrient-poor because rapid biological uptake and heavy precipitation store nutrients in living plants or leach them away.

Boreal forest soil status

Nutrient-poor and acidic because cold temperatures severely retard decomposer bacterial activity.

Temperate forest soil status

Nutrient-rich because autumn leaf drop supplies organic matter and moderate warmth enables steady decomposition.

Climate-driven biome shifts

The migration of ecological biomes poleward or upward in elevation as global temperatures increase.

Aquatic biome classification factors

Salinity levels, water depth, light penetration, water temperature, and flow rate.

Dissolved oxygen and temperature rule

Warmer aquatic ecosystems hold lower concentrations of dissolved oxygen gas.

Freshwater ecosystem salinity

Aquatic environments containing extremely low salt concentrations, such as lakes, rivers, and wetlands.

River ecosystem dynamics

Flowing freshwater environments with high turbulence that elevates dissolved oxygen levels through aeration.

Littoral lake zone

The shallow, sunlit edge of a lake containing rooted emergent plants.

Limnetic lake zone

The sunlit open surface waters of a lake away from shore, dominated by photosynthetic phytoplankton.

Profundal lake zone

The deep, dark open water layer of a lake located below light penetration levels.

Benthic lake zone

The muddy sediment layer at the bottom of a water body, inhabited by decomposers and detritivores.

Wetland ecosystem definition

An area submerged or saturated by water long enough to support vegetation adapted to saturated soil.

Wetland ecosystem services

Flood water absorption, groundwater recharge, nutrient and pollutant filtering, and biodiversity support.

Swamp

A wetland ecosystem characterized by saturated soils dominated by woody trees.

Marsh

A wetland ecosystem characterized by non-woody emergent vegetation like grasses, cattails, and reeds.

Bog

An acidic, nutrient-poor wetland ecosystem dominated by accumulated peat moss.

Estuary definition

A transitional coastal biome where a freshwater river meets and mixes with salty ocean water.

High estuary productivity driver

Continuous delivery of river nutrient sediments combined with shallow, sunlit waters.

Salt marsh characteristics

A temperate coastal estuary with non-woody salt-tolerant plants that serves as a nursery for aquatic organisms.

Mangrove swamp characteristics

A tropical coastal estuary featuring salt-tolerant trees with submerged prop roots that protect shorelines from erosion.

Primary producer

An autotrophic organism that converts solar energy into chemical energy via photosynthesis.

Primary consumer

A herbivorous heterotroph that consumes primary producers.

Secondary consumer

A carnivore or omnivore that consumes primary consumers.

Tertiary consumer

A carnivore that consumes secondary consumers.

Apex predator

A top carnivore at the apex of a food web that faces no natural predators.

Trophic cascade

An indirect ecological phenomenon where adding or removing a top predator alters population levels across lower trophic tiers.

Food chain

A single linear sequence showing the direct flow of energy and nutrients between organisms.

Food web

A complex network of interconnected food chains illustrating multiple energy pathways within an ecosystem.

Food web arrow orientation

Points in the direction of energy and matter transfer, from the prey or resource to the consumer.

First Law of Thermodynamics

Energy cannot be created or destroyed, only converted from one physical or chemical form to another.

Second Law of Thermodynamics

Energy transformations are inefficient, losing usable energy to entropy as heat.

10% Rule of ecological efficiency

Only approximately $10\%$ of energy in one trophic level is passed into biomass at the next trophic level.

Energy loss between trophic levels

Roughly $90\%$ of usable energy is lost through organismal respiration and metabolic heat loss.

Gross Primary Productivity (GPP)

The total amount of solar energy captured by primary producers through photosynthesis over time.

Net Primary Productivity (NPP)

The rate at which primary producers store chemical energy as biomass after subtracting cellular respiration losses.

NPP equation

$\text{NPP} = \text{GPP} - \text{RL}$ where $\text{RL}$ is respiration loss.

Solar energy capture efficiency

Plants capture only about $1\%$ of total incoming solar energy as GPP.

Carbon sink

An environmental reservoir that absorbs and stores a greater mass of carbon than it emits.

Carbon source

An environmental reservoir or human activity that releases more carbon into the atmosphere than it sequesters.

Major carbon sinks

The deep ocean, sedimentary rocks, ancient soil organic matter, and dense forests.

Major anthropogenic carbon sources

Fossil fuel combustion, large-scale deforestation, and industrial agriculture.

Fast carbon cycle processes

Biological photosynthesis, cellular respiration, decomposition, and ocean surface gas exchange.

Slow carbon cycle processes

Sedimentation, deep burial of organic carbon, fossil fuel creation, and volcanic outgassing.

Phosphorus cycle uniqueness

Lacks an atmospheric gas component, relying on geological weathering to release phosphate into soil and water.

Primary phosphorus reservoir

Sedimentary rock formations and deep ocean sediments containing phosphate minerals.

Biological requirement for phosphorus

Required for building DNA, RNA, ATP molecules, and cell membrane phospholipids.

Nitrogen fixation

The chemical process converting inert atmospheric $N_2$ gas into biologically available ammonia ($NH_3$) or ammonium ($NH_4^+$).

Nitrification

Soil bacterial conversion of ammonium ($NH_4^+$) into nitrite ($NO_2^-$) and subsequently into plant-usable nitrate ($NO_3^-$).

Assimilation in the nitrogen cycle

The process by which plants absorb soil nitrate or ammonium to produce plant proteins and nucleic acids.

Ammonification

The decomposition process where specialized decomposers break down nitrogenous waste into soil ammonium ($NH_4^+$).

Denitrification

Anaerobic soil bacterial conversion of nitrate ($NO_3^-$) back into nitrous oxide ($N_2O$) and atmospheric nitrogen gas ($N_2$).

Rhizobacteria symbiotic role

Nitrogen-fixing bacteria residing in root nodules of legume plants, exchanging fixed nitrogen for plant sugars.

Eutrophication sequence

Excess nutrient runoff triggers an algal bloom, which blocks light, kills submerged aquatic plants, and creates hypoxia during bacterial decomposition.

Dead zone driver

Extreme bacterial decomposition of dead organic algae depletes dissolved oxygen ($\text{hypoxia}$), killing fish and marine life.

Impervious surface impact

Paved human infrastructure prevents stormwater infiltration, multiplying flash runoff, soil erosion, and pollutant delivery.

Green infrastructure strategies

Permeable pavement, urban rain gardens, rain barrels, and vegetated green roofs designed to absorb stormwater.