Environmental Science Comprehensive Terminology Flashcards

A complete set of vocabulary terms from Units 1 to 9 of Environmental Science, covering ecosystems, populations, earth systems, energy, pollution, and global change.

Salinity

The concentration of dissolved salts in a body of water.

Phytoplankton

Microscopic, photosynthetic organisms that drift in aquatic environments; the foundation of aquatic food webs.

Littoral

The shallow, well-lit water near the shore of a lake or pond where rooted plants grow.

Limnetic

The open, sunlit surface water area of a lake away from the shore.

Profundal

The deep, dark zone of a body of water below the reach of effective light penetration.

Benthic

The bottom surface of an aquatic environment (ocean or lake floor).

Intertidal zone

The area of shoreline between low and high tides.

Temperate Rainforest

A coastal biome with moderate temperatures and high precipitation, dominated by large coniferous trees.

Food Web

A complex network of interlocking and overlapping food chains in an ecosystem.

$10\%$ rule

The ecological rule that roughly $10\%$ of energy is transferred from one trophic level to the next; the rest is lost mostly as heat.

Net Primary Productivity

The rate at which producers use photosynthesis to produce energy, minus the rate at which they use some of this energy through respiration.

Autotroph

An organism that produces its own food (e.g., plants using photosynthesis); a producer.

Consumer

The trophic levels of heterotrophs: Primary ($1^{st}$, eats producers), Secondary ($2^{nd}$, eats primary), Tertiary ($3^{rd}$, eats secondary), and Quaternary ($4^{th}$, eats tertiary).

Hydrologic Cycle

The continuous movement of water on, above, and below the surface of the Earth.

Surface Water

Water collecting on the ground or in a stream, river, lake, or wetland.

Oligotrophic

A body of water characterized by low nutrient levels, high dissolved oxygen, and clear water.

Mesotrophic

A body of water with a moderate level of nutrients and biological productivity.

Eutrophic

A body of water rich in nutrients, promoting a proliferation of plant life (often algae) which eventually reduces dissolved oxygen.

Climate

The long-term average of weather patterns in an area.

Grasslands: Temperate, Savanna, Chaparral

Biomes dominated by grasses/shrubs. Temperate: cold winters/hot summers. Savanna: tropical grassland with scattered trees. Chaparral: coastal biome with hot/dry summers and mild/rainy winters.

Desert

A biome characterized by very low precipitation and extreme temperature variations.

Negative Feedback loop

A system response that reverses a change, returning the system to its original state or stabilizing it.

Gross Primary Productivity

The total rate at which producers capture and store chemical energy as biomass in a given length of time.

Heterotroph

An organism that cannot synthesize its own food and relies on other organisms for nutrition; a consumer.

Closed System

A system where energy can be exchanged with the surroundings, but matter cannot.

Eutrophication

The process by which a body of water becomes overly enriched with minerals and nutrients, inducing excessive algal growth.

Thermal Stratification

The separation of lakes into three layers of different temperatures (epilimnion, metalimnion/thermocline, hypolimnion).

Fall turnover

The mixing of lake waters in the autumn, caused by cooling surface waters sinking, which redistributes oxygen and nutrients.

Swamp

A wetland dominated by woody plants and trees.

Marsh

A wetland dominated by herbaceous (non-woody) plant species.

Wetland

Land consisting of marshes or swamps; saturated land.

Estuary

The tidal mouth of a large river, where the tide meets the stream, mixing fresh and salt water.

Tropical Rain Forest

A hot, moist biome found near Earth's equator with high annual precipitation and extreme biodiversity.

Temperate Deciduous

A biome with four distinct seasons, dominated by broad-leaved trees that lose their leaves in the fall.

Positive Feedback Loop

A system response that amplifies or exacerbates a change, pushing the system further in that direction.

Respiration

The cellular process where organisms convert biochemical energy from nutrients into ATP, releasing waste products.

Decomposer

Organisms (like bacteria and fungi) that break down dead or decaying organisms.

Open System

A system that can exchange both matter and energy with its surroundings.

Temperature

A measure of the average kinetic energy of the particles in an object or environment.

Precipitation

Any form of water (rain, snow, sleet, hail) that falls from clouds and reaches the ground.

Latitude

The angular distance of a place north or south of the earth's equator.

Biome

A large naturally occurring community of flora and fauna occupying a major habitat.

Tundra

A vast, flat, treeless Arctic region where the subsoil is permanently frozen.

Permafrost

A thick subsurface layer of soil that remains frozen throughout the year.

Boreal Forest/Conifer Forest/Taiga

The cold, often swampy coniferous forest biome of high northern latitudes.

Trophic Level

Each of several hierarchical levels in an ecosystem, comprising organisms that share the same function in the food chain.

Food Chain

A hierarchical series of organisms each dependent on the next as a source of food.

Producer

An organism that creates its own food or energy (usually via photosynthesis).

Detrivore

An animal which feeds on dead organic material, especially plant detritus.

Energy Flow

The transfer of energy from one organism to another in an ecosystem.

Species

A group of living organisms consisting of similar individuals capable of exchanging genes or interbreeding.

Biodiversity

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

Genetic Diversity

The total number of genetic characteristics in the genetic makeup of a species.

Species Richness

The number of different species represented in an ecological community.

Species Abundance

The number of individuals per species relative to the total number of individuals in a community.

Ecosystem diversity

The variety of different ecosystems within a larger geographic area.

Invasive species/biotic pollution

Non-native species that cause ecological, economic, or human health harm in their new environment.

Anthropogenic

Originating in human activity; human-caused.

Island Biogeography

The study of the ecological relationships and distribution of organisms on islands (dictated by island size and distance from the mainland).

Evolution

The process by which different kinds of living organisms are thought to have developed and diversified from earlier forms.

Tolerance

The range of conditions (e.g., temperature, salinity) that an organism can withstand.

Succession

The process by which the structure of a biological community evolves over time.

Ecosystem services

The many and varied benefits to humans provided by the natural environment (e.g., water purification, pollination).

Bottleneck

A sharp reduction in the size of a population due to environmental events, reducing genetic diversity.

Keystone species

A species on which other species in an ecosystem largely depend, such that if it were removed the ecosystem would change drastically.

Indicator species

A species whose presence, absence, or abundance reflects a specific environmental condition.

Pioneer species

The first species to colonize previously disrupted or damaged ecosystems.

Habitat Fragmentation

The breaking apart of continuous habitat into distinct, separated pieces.

Specialist

A species with a narrow ecological niche, requiring highly specific conditions or diets.

Generalist

A species able to thrive in a wide variety of environmental conditions and make use of a variety of resources.

Natural Selection

The process whereby organisms better adapted to their environment tend to survive and produce more offspring.

Endangered species

A species of animal or plant that is seriously at risk of extinction.

Poaching

The illegal hunting, capturing, or harvesting of wild animals or plants.

Domestication

The process of taming an animal or cultivating a plant for food or human use over generations.

Zero Population Growth

The maintenance of a population at a constant level by limiting the number of live births to only what is needed to replace the existing population.

Migration

Seasonal movement of animals, or movement of humans, from one region to another.

Infant Mortality Rates (IMR)

The number of deaths per $1,000$ live births of children under one year of age.

Replacement Level Fertility (RLF)

The total fertility rate required to offset the average number of deaths in a population.

Total Fertility Rate (TFR)

The average number of children that would be born to a woman over her lifetime.

Demographic Transition

A model describing the historical shift of birth and death rates from high to low levels in a population.

K-selected species

Species that produce few offspring but invest high amounts of parental care.

r-selected species

Species that produce many offspring with little to no parental care, prioritizing high growth rates.

Biotic potential

The maximum reproductive capacity of a population under optimum environmental conditions.

Survivorship curve

A graph showing the number or proportion of individuals surviving to each age for a given species or group.

Carrying capacity

The maximum population size of a biological species that can be sustained by that specific environment.

Cohort

A group of individuals of the same age or sharing a common characteristic in a population.

Birth rate

The number of live births per thousand of population per year.

Death rate

The number of deaths per thousand of population per year.

Density-independent factor

Factors (like weather or natural disasters) that affect population size regardless of population density.

Density-dependent factor

Factors (like disease, competition, or predation) whose effects on the size or growth of the population vary with the population density.

Rule of $70$

A math formula used to estimate the doubling time of a population ($70$ divided by the annual growth rate percentage).

Population Density

The number of individuals per unit geographic area.

Exponential Growth

Growth whose rate becomes ever more rapid in proportion to the growing total number (J-curve).

Logistic Growth

Population growth that levels off as population size approaches carrying capacity (S-curve).

Limiting Factor

An environmental condition or resource that restricts the size or distribution of a population.

Survivorship: Type I, Type II, Type III

Type I: High early survival, late decline. Type II: Constant mortality. Type III: High early mortality, high survival for remaining individuals.

Population Growth Momentum

The tendency for population growth to continue beyond replacement-level fertility due to a high concentration of people in their childbearing years.

Age Structure diagram

A demographic tool showing the distribution of various age groups in a population.

Plate tectonics

The theory that Earth's outer shell is divided into several plates that glide over the mantle.

Albedo

The proportion of the incident light or radiation that is reflected by a surface.