Ecology: Climate, Biomes, and Energy Flow Study Guide

This set of vocabulary flashcards covers terrestrial biomes, atmospheric and aquatic climate terms, physiological adaptations to environmental stress, and energy flow through ecosystems and food webs.

Tropical Rainforests

Located in low-latitude tropics ($10^\circ N–10^\circ S$) with consistently high temperature and precipitation, dominated by broad-leaved evergreen and deciduous trees.

Tropical Seasonal Forests & Savannas

Located in the tropics ($23.5^\circ N–23.5^\circ S$) with consistently high temperatures and strongly seasonal precipitation driven by wet and dry rhythms.

Deserts

Located in subtropics ($30^\circ N$ & $30^\circ S$) high-pressure zones of Hadley cells, characterized by consistently low precipitation and vegetation like succulents.

Temperate Grasslands

Located in the temperate zone ($30^\circ–50^\circ$, N & S) with seasonal temperature and precipitation, featuring warm, wet summers and cold, dry winters dominated by grasses.

Temperate Shrublands & Woodlands

Located in the temperate zone ($30^\circ–50^\circ$, N & S) with mild seasonal temperatures and a warm, dry summer and cold-ish, wet winter.

Temperate Deciduous Forests

Located in the temperate zone ($30^\circ N–50^\circ N$) with hot, wet summers and cold, wet-ish winters, dominated by oak, maple, and beech trees.

Temperate Evergreen Forests

Located in the temperate zone ($30^\circ–50^\circ$, N & S) with seasonal mild temperatures and dominant vegetation of conifers, beeches, eucalypts, or cedar.

Boreal Forests (Taiga)

Located at $50^\circ N–65^\circ N$ with cold seasonal temperatures and consistently low precipitation, dominated by conifers like spruces and pines.

Tundra

Located at $65^\circ N–90^\circ N$ in high pressure zones of Polar cells, characterized by cold dark winters, warm-ish bright summers, and vegetation like sedges and lichens.

Weather

The short-term state of the atmosphere at a given place and time, including temperature, precipitation, and wind.

Climate

The long-term average pattern of weather conditions such as temperature and precipitation in a region.

Greenhouse effect

The warming of Earth's surface and atmosphere caused by greenhouse gases absorbing and re-emitting infrared radiation.

Latent heat flux

The transfer of heat associated with a change in the phase of water such as evaporation or condensation.

Conduction

The transfer of heat through direct molecular contact between substances.

Convection

The transfer of heat through the movement or circulation of a fluid such as air or water.

Sensible heat flux

The transfer of heat between the surface and atmosphere due to a temperature difference, without a change of phase.

Greenhouse gases

Atmospheric gases like $CO_2$, methane, and water vapor that absorb and re-emit infrared radiation to warm the atmosphere.

Uplift

The rising of air, often as it is heated or forced over terrain, leading to cooling and condensation.

Atmospheric pressure

The force exerted by the weight of air in the atmosphere above a given point.

Subsidence

The sinking of air, typically associated with high pressure and dry conditions.

Hadley cell

A large-scale atmospheric circulation pattern in which air rises near the equator and sinks around $30^\circ N/S$.

Polar cells

Atmospheric circulation cells in which air rises near $60^\circ N/S$ and sinks at the poles.

Ferrell cell

The mid-latitude atmospheric circulation cell located between the Hadley and Polar cells.

Tropical zone

The region of Earth near the equator, generally between $23.5^\circ N$ and $23.5^\circ S$.

Tropics

The latitudinal belt around the equator bounded by the Tropic of Cancer and Tropic of Capricorn.

Polar zones

The regions near the North and South Poles, characterized by cold temperatures year-round.

Temperate zones

The mid-latitude regions between the tropics and polar zones, with distinct seasons.

Coriolis effect

The apparent deflection of moving air or water caused by Earth's rotation.

Heat capacity

The amount of heat required to raise the temperature of a substance by a given amount.

Downwelling

The downward movement of surface water, often associated with convergence of currents.

Upwelling

The upward movement of deep, often nutrient-rich, water to the surface.

Lapse rate

The rate at which air temperature decreases with increasing altitude.

Maritime climate

A climate moderated by proximity to large bodies of water, resulting in milder temperature swings.

Continental climate

A climate found in interior regions away from oceans, with larger temperature swings between seasons.

Rain shadow effect

Reduced precipitation on the leeward side of a mountain range due to air drying as it descends.

Albedo

The proportion of incoming solar radiation that is reflected by a surface.

Evapotranspiration

The combined loss of water from a landscape through evaporation and plant transpiration.

Intertropical convergence zone

A band near the equator where trade winds from the north and south converge, producing heavy rainfall.

Stratification

Layering of a water body based on differences in temperature and density.

Epilimnion

The warm, well-mixed surface layer of a stratified lake.

Thermocline

A layer in a body of water where temperature changes rapidly with depth.

Hypolimnion

The cold, dense bottom layer of a stratified lake.

Turnover

The seasonal mixing of a lake's water layers when temperature differences between layers disappear.

El Niño Southern Oscillation (ENSO)

A recurring climate pattern involving changes in sea surface temperatures and pressure across the tropical Pacific.

North Atlantic Oscillation

A climate pattern reflecting fluctuations in atmospheric pressure differences between the Azores and Iceland.

Pacific Decadal Oscillation

A long-term pattern of climate variability in the Pacific Ocean on a decadal timescale.

Salinity

The concentration of dissolved salts in water.

Salinization

The accumulation of salts in soil or water, often due to evaporation or irrigation.

Acidity

A measure of the concentration of hydrogen ions in a solution, expressed on the pH scale.

Alkalinity

A measure of water's capacity to neutralize acids, related to dissolved carbonate/bicarbonate compounds.

Hypoxic

Describes water with very low dissolved oxygen concentration, insufficient to support most aquatic life.

Tolerance

The ability of an organism to survive and function across a range of an environmental factor.

Avoidance

A strategy in which an organism avoids exposure to unfavorable environmental conditions altogether.

Physiological ecology

The study of how organisms' physiological processes are shaped by, and respond to, their environment.

Climate envelope

The set of climatic conditions within which a species can persist.

Stress

An environmental condition that pushes an organism's physiology away from its optimal functioning.

Acclimatization

A reversible physiological adjustment an individual organism makes in response to environmental change over its lifetime.

Adaptations

Heritable traits that have evolved because they improve an organism's fit to its environment.

Ecotypes

Genetically distinct populations of a species that are adapted to local environmental conditions.

Stomates

Small pores, mainly on leaves, through which plants exchange gases and lose water vapor.

Pubescence

A covering of fine hairs on plant surfaces that can reduce water loss and reflect light.

Dormancy

A period of suspended growth or development that allows an organism to survive unfavorable conditions.

Ectotherms

Organisms whose body temperature is largely determined by their external environment.

Endotherms

Organisms that maintain a relatively constant internal body temperature through metabolic heat production.

Thermoneutral zone

The range of environmental temperatures over which an endotherm's metabolic rate stays at a minimum baseline.

Lower critical temperature

The environmental temperature below which an endotherm must increase metabolic heat production.

Hibernation

A state of significantly reduced metabolic rate and body temperature used to survive cold or food-scarce periods.

Torpor

A short-term state of decreased physiological activity, typically lowered body temperature and metabolism.

Boundary layer

A thin layer of still air or fluid adjacent to a surface influencing heat, gas, or water exchange.

Water potential

A measure of the tendency of water to move from one area to another, driven by pressure, concentration, and gravity.

Gravitational potential

The component of water potential due to the effect of gravity on water.

Pressure (or turgor) potential

The component of water potential resulting from physical pressure, such as that from a cell wall.

Turgor pressure

The pressure of the cell contents against the cell wall, resulting from water uptake.

Matric potential

The component of water potential due to the attraction of water to surfaces like soil particles.

Resistance

In water transport, the opposition to water flow through a pathway like soil, roots, or xylem.

Osmotic potential

The component of water potential due to the concentration of dissolved solutes in a solution.

Osmotic adjustment

A physiological process of changing internal solute concentration to maintain water uptake under stress.

Photosynthesis

The process of converting light energy into chemical energy, producing organic compounds from $CO_2$ and water.

Chemosynthesis

The process of producing organic compounds using energy from chemical reactions rather than light.

Calvin cycle

The set of light-independent reactions in photosynthesis that fix $CO_2$ into organic molecules using ATP and NADPH.

Fixation

The conversion of an inorganic form of an element into an organic or biologically usable form.

C3 photosynthetic pathway

A pathway where $CO_2$ is fixed directly via the Calvin cycle; less efficient in hot, dry conditions due to photorespiration.

C4 photosynthetic pathway

A pathway that fixes $CO_2$ into a four-carbon compound to concentrate it around the Calvin cycle and reduce photorespiration.

Crassulacean acid metabolism (CAM)

A photosynthetic pathway where plants take up $CO_2$ at night and fix it during the day to reduce water loss.

Photorespiration

A process where the CO2-fixing enzyme binds oxygen instead, leading to a loss of fixed carbon.

Heterotrophs

Organisms that obtain energy and carbon by consuming organic matter produced by other organisms.

Detritus

Dead organic matter that serves as a food source for detritivores and decomposers.

Biomass

The total mass of living organisms in a given area.

Ecosystem

A community of organisms together with the physical environment with which they interact.

Primary production

The conversion of light or chemical energy into organic compounds by autotrophs.

Gross primary production (GPP)

The total amount of energy captured through photosynthesis or chemosynthesis by autotrophs.

Net primary production (NPP)

The energy remaining after autotrophs use some production for respiration: $NPP = GPP - \text{autotroph respiration}$.

Leaf area index

The total one-sided area of leaf tissue per unit of ground surface area.

Net ecosystem exchange (NEE)

The net flux of $CO_2$ between an ecosystem and the atmosphere, accounting for photosynthesis and respiration of all organisms.

Secondary production

The production of new biomass by heterotrophs generated from the energy and materials they consume.

Herbivores

Organisms that feed primarily on plant material.

Carnivores

Organisms that feed primarily on other animals.

Omnivores

Organisms that feed on both plant and animal material, occupying multiple trophic levels.

Detritivores

Organisms that feed on dead organic matter.

Net secondary production

The energy or biomass gained by a consumer population through growth and reproduction after losses.