APES Unit 1 & Unit 2 Vocabulary (finished)

Terrestrial Biomes

Biomes on land (forests, taiga, tundra, etc.)

Aquatic Biomes

oceans, estuaries, lakes, and ponds

The Carbon Cycle

The series of processes by which carbon compounds are interconverted in the environment, chiefly involving the incorporation of carbon dioxide into living tissue by photosynthesis and its return to the atmosphere through respiration, the decay of dead organisms, and the burning of fossil fuels.

The Nitrogen Cycle

The series of processes by which nitrogen and its compounds are interconverted in the environment and in living organisms, including nitrogen fixation and decomposition.

The Phosphorus Cycle

The cyclic movement of phosphorus in different chemical forms from the environment to organisms and then back to the environment

The Hydrologic Cycle

The cycle through which water in the hydrosphere moves, including such processes as evaporation, precipitation, and surface and groundwater runoff

Primary Productivity

The rate at which solar energy (sunlight) is converted into organic compounds via photosynthesis over a unit of time. (measured in units of energy per unit area per unit time, ex. kcal/m2/yr)

Gross primary productivity

total rate of photosynthesis in a given area

Net Primary Productivity

The rate of energy storage by photosynthesizers in a given area, after subtracting the energy loss to respiration.

Tropic Levels

Each step in a food chain or food web where energy is transferred

Energy Flow

The passage of energy through the components of an ecosystem

10% Rule

Only 10% of the total energy produced at each trophic level is available to the next level. The amount of energy passed up to the levels of the food pyramid reduces as you go up.

Food chains

Energy links between different organisms in an ecosystem based on feeding habits.

Food webs

A system of interlocking and interdependent food chains.

predator

An animal that hunts other animals for food

Prey

An organism that is killed and eaten by another organism

Mutualism (symbiosis)

A symbiotic relationship where both organisms benefit.

Commensalism (symbiosis)

A relationship between two organisms in which one organism benefits and the other is unaffected

Parasitism (symbiosis)

A relationship between two organisms in which one organism benefits and the other is harmed

competition

The struggle between organisms to survive in a habitat with limited resources

interspecific competition

competition between members of different species, such as lions and hyenas, competing for food

intraspecific competition

competition between members of the same species for the same limited resource

Biodiversity

The variety of life in the world or in a particular habitat or ecosystem.

TUNDRA

A cold, treeless biome found near the Arctic with permafrost, low precipitation, short growing seasons, and low biodiversity. Plants grow close to the ground, and animals migrate or have thick fur for insulation.

CONIFEROUS FOREST (TAIGA / BOREAL FOREST)

A biome of evergreen, needle-leaf trees located in northern latitudes with cold winters, moderate precipitation, acidic nutrient-poor soil, and moderate biodiversity. It is the largest terrestrial biome on Earth.

DECIDUOUS FOREST (TEMPERATE SEASONAL FOREST)

A temperate biome with four distinct seasons, moderate rainfall, fertile soil, and trees that lose their leaves in winter. It supports high biodiversity and is heavily affected by human activity.

GRASSLANDS (TEMPERATE GRASSLANDS / PRAIRIES)

A biome dominated by grasses instead of trees, with moderate rainfall, frequent fires, fertile soil, and large grazing animals. It has been widely converted into farmland for agriculture.

SAVANNA

A tropical grassland biome with scattered trees, warm temperatures year-round, distinct wet and dry seasons, and large herbivores like elephants and giraffes. Fires help maintain grass dominance.

DESERT

A biome that receives less than 25 cm of rainfall per year, with extreme temperature variations, sparse vegetation, and plants and animals adapted to conserve water.

TROPICAL RAINFOREST

A hot, wet biome near the equator with year-round warmth, heavy rainfall, thin nutrient-poor soil, and the highest biodiversity of any biome on Earth.

TEMPERATE RAINFOREST

A cool, coastal biome with high rainfall, mild temperatures, nutrient-rich soil, and large evergreen trees. It has very high biomass and productivity.

SHRUBLAND (CHAPARRAL)

A biome with hot, dry summers, cool, wet winters, and fire-resistant shrubs. Found in coastal regions like California and characterized by periodic wildfires.

STREAMS & RIVERS

Flowing freshwater ecosystems that move in one direction and are highly oxygenated, supporting organisms adapted to fast-moving water such as fish, insects, and algae.

PONDS & LAKES

Standing freshwater ecosystems where sunlight may or may not reach the bottom depending on depth. These systems contain layered temperature zones, moderate biodiversity, and support fish, plants, algae, and plankton.

WETLANDS

Transitional ecosystems between land and water that are periodically flooded, extremely nutrient-rich, and provide water filtration, flood control, and wildlife habitat. Examples include marshes and swamps.

MARSHLANDS

A type of wetland dominated by grasses and soft-stem plants rather than trees. Marshlands filter pollutants, reduce flooding, and serve as important breeding grounds for birds, fish, and amphibians.

ESTUARIES

Areas where freshwater from rivers mixes with saltwater from the ocean, creating brackish water with high nutrient levels and very high biodiversity. Estuaries act as nurseries for many marine species.

INTERTIDAL ZONE

The coastal zone that lies between high tide and low tide, where organisms must survive constant changes in water level, temperature, and wave action.

OPEN OCEAN ECOSYSTEM

The vast deep-water marine ecosystem beyond the continental shelf that receives little sunlight, has low nutrients, and supports organisms such as plankton, whales, and large predatory fish.

CORAL REEFS

Warm, shallow marine ecosystems made of calcium carbonate structures built by coral animals, known for extreme biodiversity and sensitivity to temperature and pollution.

Sulfur Cycle

The movement of sulfur through the lithosphere, hydrosphere, atmosphere, and biosphere, primarily through rock weathering, volcanic activity, and decomposition.

Why is sulfur important?

Sulfur is an essential nutrient used to form proteins and enzymes in living organisms.

Main reservoirs of sulfur

The lithosphere, especially sedimentary rocks and ocean sediments.

Atmospheric sulfur compounds

Sulfur dioxide (SO₂) and hydrogen sulfide (H₂S).

Human impact on the sulfur cycle

Burning fossil fuels releases SO₂, which reacts with water in the atmosphere to form acid deposition (acid rain).

Natural sources of sulfur emissions

Volcanic eruptions, sea spray, and decomposition of organic matter.

Hydrologic Cycle

The continuous movement of water through Earth's systems via evaporation, transpiration, condensation, precipitation, infiltration, runoff, and percolation.

Evaporation

The process by which liquid water is converted into water vapor due to solar energy.

Transpiration

The release of water vapor from plant leaves into the atmosphere.

Condensation

Water vapor cooling and forming liquid droplets (cloud formation).

Precipitation

Water falling to Earth as rain, snow, sleet, or hail.

Infiltration/Recharge

Water soaking into the soil.

Percolation

The downward movement of water through soil and rock layers to groundwater.

Groundwater

Water stored underground in aquifers.

Percent of Earth's surface covered by water

Approximately 71%.

Accessible freshwater

Less than 1% of Earth's total water is available for human use.

Human impact on water cycle

Urbanization, dams, groundwater depletion, pollution, and increased runoff.

Phosphorus Cycle

The movement of phosphorus through the lithosphere, hydrosphere, and biosphere with no significant atmospheric phase.

Nitrogen Cycle

The movement of nitrogen through the atmosphere, biosphere, hydrosphere, and lithosphere.

Atmospheric nitrogen (N₂)

Makes up about 78% of the atmosphere but is biologically unavailable to most organisms.

Nitrogen fixation

Conversion of atmospheric nitrogen (N₂) into ammonia (NH₃) by bacteria or lightning.

Nitrification

Bacteria convert ammonia into nitrites (NO₂⁻) and then nitrates (NO₃⁻).

Assimilation

Plants absorb nitrates or ammonium to build organic molecules.

Ammonification

Decomposers convert organic nitrogen from dead organisms into ammonia.

Denitrification

Bacteria convert nitrates back into nitrogen gas (N₂), returning it to the atmosphere.

How animals obtain nitrogen

By consuming plants or other animals.

Human impact on the nitrogen cycle

Synthetic fertilizers, fossil fuel combustion, eutrophication, smog, and acid deposition.

Carbon Cycle

The movement of carbon through the atmosphere, biosphere, hydrosphere, and geosphere.

Role of carbon in ecosystems

Carbon is the backbone of organic molecules and is essential for life.

Photosynthesis (carbon)

Producers remove CO₂ from the atmosphere and convert it into organic carbon.

Cellular respiration

Organisms release CO₂ back into the atmosphere.

Decomposition (carbon)

Breakdown of organic matter that releases carbon to soil and atmosphere.

Combustion

Burning fossil fuels or biomass releases CO₂ into the atmosphere.

Carbon sinks

Natural systems that store carbon, such as oceans, forests, and rocks.

Largest carbon reservoir

Sedimentary rocks (carbonate rocks).

Greenhouse gases

Gases like CO₂ that trap heat in the atmosphere.

Human impact on carbon cycle

Fossil fuel combustion and deforestation increase atmospheric CO₂ and global warming.

Respiration

Cellular process where organisms break down glucose for energy and release CO₂ to the atmosphere/water.

Fossil fuels

Coal, oil, and natural gas formed from buried organic matter over millions of years; burning them releases stored carbon as CO₂.

Plants (carbon cycle role)

Producers that remove CO₂ from air/water through photosynthesis and store carbon in biomass.

Animals (carbon cycle role)

Consumers that obtain carbon by eating other organisms and release CO₂ through respiration.

Greenhouse gas (CO₂)

Atmospheric gas that absorbs infrared radiation and traps heat; increased CO₂ strengthens the greenhouse effect and contributes to climate change.

Carbonate (CO₃²⁻) / carbonate rocks

Long-term inorganic carbon storage forms in oceans and sediments; carbonate combines with calcium to form limestone and other carbonate rocks.

Nitrifying bacteria

Soil/water bacteria that perform nitrification, converting ammonia (NH₃/NH₄⁺) into nitrite and then nitrate.

Nitrite (NO₂⁻)

Intermediate nitrogen form produced during nitrification (from ammonia) and converted into nitrate.

Nitrate (NO₃⁻)

Plant-available nitrogen form; highly soluble and easily leaches into groundwater and runoff into waterways.

Ammonia (NH₃) / ammonium (NH₄⁺)

Reduced nitrogen produced by decomposition (ammonification) or fertilizers; starting form for nitrification.

Decay / Decomposition (nitrogen)

Breakdown of dead organisms and waste by decomposers, releasing organic nitrogen and producing ammonia/ammonium (ammonification).

Denitrifying bacteria

Bacteria that convert nitrate (NO₃⁻) into nitrogen gas (N₂), returning nitrogen to the atmosphere (denitrification).

Plants (nitrogen cycle role)

Assimilate nitrate (NO₃⁻) or ammonium (NH₄⁺) to build proteins and nucleic acids.

Eutrophication (nitrogen)

Excess nitrogen (often nitrates) entering water causes algal blooms; decomposition of algae reduces dissolved oxygen, leading to hypoxia and fish kills.

Acid rain (nitrogen)

Precipitation made acidic partly by nitrogen oxides (NOₓ) from burning fossil fuels forming nitric acid (HNO₃), which acidifies soils and surface waters.

Long-term phosphorus cycle

Movement of phosphorus through rock formation, uplift, and weathering over geologic time; main storage is sedimentary rock and marine sediments.

Short-term phosphorus cycle

Rapid cycling of phosphate through soil, water, plants, animals, and decomposers within ecosystems.

Phosphate ion (PO₄³⁻)

The usable form of phosphorus taken up by plants; moves through food webs and can cause eutrophication when excessive.

Plants (phosphorus role)

Absorb phosphate (PO₄³⁻) from soil/water to build ATP, DNA/RNA, and membranes.

Animals (phosphorus role)

Obtain phosphorus by eating plants/animals; important for ATP, DNA/RNA, and bones/teeth.

Birds (phosphorus role)

Birds can concentrate and transport phosphorus via guano (droppings), adding phosphate to soils and coastal systems.

Decay / Decomposition (phosphorus)

Decomposers return phosphorus from dead organisms and waste back to soil/water as phosphate.

Limestone (phosphorus connection)

Sedimentary rock formed in marine environments; phosphorus can be stored in sediments/rocks associated with long-term cycling and burial.