BIOL 4253: Principles of Ecology - The Physical Environment

Flashcards on Physical Environment based on lecture notes.

Weather

The temperature, humidity, precipitation, wind, and cloud cover at a specific time and place.

Climate

Long-term weather patterns, often a 30-year average trend at the local, regional, or global scale.

Albedo

The percentage of incident solar radiation reflected back by a surface (e.g., snow and ice: 0.8–0.9; forest: 0.05).

Greenhouse Gases

Gases (H2O, CO2, etc.) that absorb longwave radiation emitted into the atmosphere.

Axial Tilt

The Earth's tilt of 23.5°, which causes the seasons and seasonality increases towards the poles.

Hadley Cell

An atmospheric circulation cell characterized by an equatorial low and subtropical high-pressure zone.

Coriolis Effect

The deflection of air flow in each hemisphere due to Earth’s rotation (clockwise in the Northern Hemisphere, counterclockwise in the Southern Hemisphere).

Gyres

Circular systems of surface water flow driven by prevailing winds that redistribute heat towards the poles.

Relative Humidity

The amount of water vapor in the air as a percent of saturation vapor pressure.

ITCZ (Intertropical Convergence Zone)

A zone around the equator where warm trade winds meet, leading to rising air, adiabatic cooling, and precipitation.

Continentality

The pattern of higher seasonal variation in temperature for land areas farther from the coast due to water's high specific heat.

Lapse Rate

The rate at which atmospheric temperature decreases with altitude due to lower air density and pressure.

Rain Shadow

A dry area on the leeward side of a mountain, caused by adiabatic cooling and precipitation on the windward side.

Microclimate

Local conditions that differ from the broader regional climate, affecting species activity and distribution.

Urban Heat Island

A phenomenon where urban areas experience higher temperatures due to changes in land use (heat-trapping materials).

Hydrologic Cycle

Circulation of water through different pathways and storages, including evaporation, transpiration, precipitation, interception, infiltration, percolation, and surface runoff.

Cohesion

Water molecules sticking to each other, creating surface tension, due to hydrogen bonding.

Adhesion

Water molecules sticking to other sufaces, facilitating capillary action, due to hydrogen bonding.

High Specific Heat (of water)

A property of water that helps prevent extreme seasonal temperature fluctuations (4.184 J⋅kg−1⋅K−1).

Pycnocline

A density gradient in the ocean due to temperature and salinity changes.

Aphotic Zone

The zone in aquatic environments below 200m where light transmittance is less than 1%.

Thermocline

Temperature gradient in a body of water, separating the epilimnion (warmer, less dense) from the hypolimnion (colder, denser).

Salinity

A measure of the salt content in water, typically expressed in practical salinity units (psu) or parts per thousand (‰).

Upwelling

The process by which cold, oxygenated, nutrient-rich deepwater rises to the surface, triggered by winds and currents.

Estuary

A partially enclosed coastal body of water where freshwater from rivers mixes with saltwater from the ocean, creating a salinity gradient.

Photo. active radiation (PAR)

Light available for photosynthesis, typically in the range of 400-700 nm.

Leaf area index (LAI)

Leaf area per ground area (e.g., m2/m2).

Soil

Transitional zone between vegetation and bedrock.

Ion Exchange Capacity

The capacity of soil to retain cations (e.g., Ca2+, Mg2+, NH4 +) or anions (NO3 − , PO3 4− , SO4 2−).

Laterization

A soil-forming process involving rapid weathering and heavy leaching, resulting in soils enriched with aluminum and iron oxides.

Calcification

A soil-forming process characterized by the buildup of CaCO3 and alkaline salts in the subsoil.

Salinization

A soil-forming process leading to an increase of salts at or near the surface of the soil.

Podzolization

An extreme soil-forming process involving heavy leaching that removes Fe and Al from surface layers.

Gleization

A soil-forming process creating blue-gray gley in an anaerobic environment (poor drainage, slow decomposition, buildup of organics).