Environmental Science - Chapter 1: Basic Unit of Ecology

Vocabulary flashcards generated from lecture notes on basic ecological concepts, biotic and abiotic components, biogeochemical cycles, food webs, and ecological pyramids.

Ecology

Scientific study of living organisms and their interactions with each other and their environment.

Ernst Haeckel

The German scientist who first used the word "ecology" in 1866, coined from the Greek word "Oikos" (house) and Latin word "logos" (study of household).

Organism

Level of ecological organization referring to just one living being.

Population

The number of one kind of living organism in an ecosystem.

Community

All the living things in one ecosystem.

Ecosystem

All the living and non-living things in a specific area.

Biosphere

The largest level of ecological organization, representing all life on Earth.

Biotic Factors

Also known as biological factors, these are the living organisms in an ecosystem.

Autotrophs

Producers that make their own food from inorganic substances.

Photoautotrophs

Producers that use sunlight through photosynthesis to make food, such as green plants.

Chemoautotrophs

Producers that use chemical energy through chemosynthesis in places without sunlight, such as deep-sea bacteria.

Heterotrophs

Consumers that obtain energy by feeding on other organisms.

Herbivores

Primary consumers that eat plants.

Carnivores

Secondary consumers that eat animals.

Omnivores

Consumers that eat both plants and animals.

Decomposers

Also known as microconsumers, organisms such as bacteria and fungi that break down dead organisms and organic waste, returning nutrients to the environment.

Abiotic Factors

Also known as physical factors, these are non-living physical and chemical factors that influence the survival, growth, and functions of organisms in an ecosystem.

Heliophytes

Plants that grow best in full sunlight.

Sciophytes

Plants that grow best in shaded or low-light areas.

Hydrophytes

Plants adapted to grow in water, such as water lilies.

Mesophytes

Plants requiring moderate amounts of water, such as corn.

Xerophytes

Plants adapted to dry environments, such as cacti.

Physiographic Factors

Physical features of the land, such as altitude, slope, and land position, that influence temperature, soil quality, plant growth, and animal behavior.

Biogeochemical Cycles

The continuous movement and recycling of essential nutrients between living organisms (biotic) and the non-living environment (abiotic).

Carbon Cycle

The continuous movement of carbon between the atmosphere, living organisms, oceans, and Earth's crust.

Oxygen Cycle

The continuous movement and recycling of oxygen between the atmosphere, living organisms, water, and Earth's surface.

Nitrogen Fixation

The process of converting unreactive atmospheric nitrogen gas ($N_2$) into usable forms, occurring non-biologically via lightning or biologically via specialized bacteria.

Nitrification

The biological process in which aerobic bacteria convert compounds into nitrite ions, which are then converted by other bacteria into nitrate ions absorbable by plants.

Denitrification

The biological process where a group of bacteria changes nitrate back into nitrogen gas ($N_2$), returning it to the atmosphere.

Phosphorus Cycle

An example of a sedimentary cycle whose main reservoir occurs in soil water, bodies of water, rocks, and ocean sediments.

Adenosine Triphosphate (ATP)

Known as the energy currency of the cell; it stores and provides energy for cellular processes and requires phosphorus to function.

Hydrologic Cycle

The continuous movement of water through Earth's atmosphere, land, and oceans, powered by energy from the sun and gravity.

Evapotranspiration

The combined processes of evaporation (liquid into water vapor) and transpiration (water released by plants).

First Law of Thermodynamics

Principle stating that energy cannot be created or destroyed, but can only be transformed from one form to another.

Second Law of Thermodynamics

Principle stating that energy transfer is not 100% efficient because some energy is lost as heat during every transfer.

Food Chain

A simple sequence that shows how energy moves from one organism to another through feeding.

Trophic Level

The feeding position of an organism in a food chain or food web.

Food Web

A network of interconnected food chains showing realistic feeding relationships in nature.

Grazing Food Web

A type of food web that begins with living plants (producers) as the source of energy.

Detritus Food Web

A type of food web that begins with dead organic matter (detritus) broken down by decomposers.

Ecological Pyramid

A diagram showing the trophic levels in an ecosystem and how energy, biomass, and the number of organisms change from producers to top consumers.

Charles Elton

British ecologist and Father of Animal Ecology who introduced the concept of the ecological pyramid in 1927.

Energy Pyramid

Diagram illustrating the flow of energy from one trophic level to the next, where only about $10$ to $30$ percent of energy is transferred and $70$ to $90$ percent is lost as heat or used for growth.

Biomass Pyramid

Diagram showing the total mass of living organisms present at each trophic level.

Number Pyramid

Diagram representing the number of organisms at each trophic level without considering their physical size.