Unit 1 - The Living World: Ecosystems

Ecosystem

A specific location on Earth where living organisms (biotic factors) interact with each other and with their non-living environment (abiotic factors)

Biotic factors

Living parts of an ecosystem

Abiotic factors

Nonliving parts of an ecosystem

Niche

The specific role or position that an organism occupies within its ecosystem

Habitat

The natural environment where a particular species or organism lives and obtains the resources it needs to survive

Community

Organisms that interact with each other and occupy a specific area

Population

All the individuals of a single species that live together in a specific geographic area

Species

A group of organisms that is distinct from other and are capable of successfully interbreeding to produce fertile offspring

Biodiversity

The variety of different species of plants, animals, and other living organisms that exist within a particular ecosystem

Ecological succession

The gradual process of change in species composition and community structure in an ecosystem over time

Biome

Large ecological area with distinct climate and species

Tundra

Cold, low precipitation, permafrost, low biodiversity

Taiga (Boreal Forest)

Cold, more precipitation than tundra, coniferous trees

Temperate rainforest

Moderate temperatures, high precipitation, evergreen trees

Temperate seasonal forest (deciduous)

Four seasons, moderate rainfall, deciduous trees

Tropical rainforest

Warm, high precipitation, high biodiversity

Shrubland (chaparral)

Hot, dry summers and mid, wet winters; fire-adapted

Temperate grassland (prairie)

Cold winters, hot summers, moderate rainfall

Savanna

A widespread grassland area that contains small shrubs and few trees, too dry and hot

Desert

Dry, extreme temperatures, specialized drought-resistant plants

Climatogram (climate diagram)

Graph showing temperature and precipitation patterns of a biome

Freshwater

Includes lakes, ponds, rivers, and streams
Low salinity in water

Saltwater (marine)

Contains a significant concentration of dissolved salts

Wetlands

Characterized by presence of water, permanently/seasonally that support aquatic plants and wildlife (mangroves)

Estuaries

-Where rivers meet the ocean, enclosed bodies of water where freshwater mixes with saltwater

Coral reefs

Diverse underwater ecosystems formed by colonies of tiny animals called coral polyps. Thrives in warm, shallow awters with clear sunlight and provide habitiats.

Intertidal zone

-Area of shoreline between low and high tides

Open ocean (pelagic zone)

The vast expanse of seawater that extends beyond costal areas and continental shelves

Photic zone

Upper layer of a body of water where sunlight can penetrate sufficiently for photosynthesis to occur

Aphotic zone

Deeper layer of body of water that receives little to no sunlight

Littoral zone

-Shallow area of a body of water such as lake or pond where sunlight reaches the bottom and supports plant growth

Benthic zone

The lowest level of a body of water, where organisms live on or in the sediment at the bottom

Phosphorus

Critical element that supports life by helping organisms build the moleces necessary for growth
Crucial for DNA, ATP, cell membranes

Weathering

The process that breaks down rocks and minters, organic phosphorus is released

Runoff

Excess phosphorus from farmland, lawns, and even certain detergents enters streams, feeding algae and upsetting normal ecological balances.

Sedimentation

Process by which particles settle out of a fluid and accumulate at the bottom over time

No atmospheric component (important distinguishing fact)

-There is no atmospheric component in the phosphorus cycle

Evaporation

-The process by which a liquid turns into vapor or gas due to heat energy

Condensation

The process where water vapor in the atmosphere cools and changes into liquid water

Precipitation

Any form of moisture that falls from the atmosphere onto Earth’s surface

Infiltration

The process by which water on the ground surface enters the soil

Percolation

The process of water seeping through soil or rock layers and moving downward into the ground

Runoff

The process where water flows over the surface of the ground and eventually makes its way into rivers, lakes, and oceans

Transpiration

Plants release water vapor into the atmosphere through their leaves

Gross Primary Productivity (GPP)

The total amount of organic matter or biomass produced by photosynthetic organisms in a given area over a specific time

Net Primary Productivity (NPP)

The amount of energy that remains after plants have used some of their captured energy for their own respiration

Respiration

The process by which living organisms release stored energy from organic compounds to carry out life functions

Photosynthesis

The process through which green plants use sunlight, carbon dioxide and water to produce glucose and oxygen.

Limiting factors (e.g., sunlight, nutrients)

-Environmental conditions that restrict the growth, abundance, or distribution of a population within an ecosystem

Producer (autotroph)

Organisms that make their own food or energy

Primary consumer (herbivore)

Organism that directly feeds on producers

Secondary consumer (carnivore)

An organism that feeds on primary consumers

Tertiary consumer

Organisms that feed on secondary consumers

Decomposer

Organisms that break down dead organic matter into simpler substances

Detritivore

Organisms that consume detritus, which is dead organic matter like fallen leaves or animal waste

Trophic level

The different levels in a food chain or food web

Energy pyramid

A graphical representation that shows the flow of energy through different trophic levels in an ecosystem

10% Rule

Only 10% of energy from one trophic level is able to move up to the next

Energy efficiency

Using less energy to accomplish the same tasks or achieve the same level of comfort

Heat loss

The transfer of thermal energy from a system to its surrounding environment

Law of Thermodynamics (especially Second Law: energy degradation)

1 - The law of conservation of energy which states that energy is neither created nor destroyed
2 - When energy is converted from one form to another, some energy is lost and efficiency decreases

Food chain

Shows how different organisms in an ecosystem depend on each other for food and how energy is transferred linearly

Food web

A complex network of interconnected food chains within an ecosystem

Keystone species

Organisms that have a disproportionately large impact on their ecosystem relative to their abundance.

Trophic cascade

Ecological changes that occur when there are alterations at one trophic level that impact multiple levels

Energy flow

The transfer of energy through a biological community, primarily through food chains and food webs

Top-down vs. bottom-up control

Top-down: populations at higher trophic levels control the populations at lower trophic levels

Bottom-up: populations at lower trophic levels control the populations at the higher levels of the food web