The Physical Environment and Physiological Tolerances

A set of flashcards summarizing key concepts from the lecture on the physical environment and physiological tolerances, including definitions and processes relevant to ecological and biological studies.

Physical Environment

Comprises abiotic factors affecting an organism's survival, growth, and reproduction, including air, soil, temperature, and water.

Physiological Tolerance Curves

Graphs that illustrate how a species responds to environmental gradients.

Fundamental Niche

The total range of environmental conditions that a species could theoretically tolerate.

Realized Niche

The actual portion of the fundamental niche occupied by a species after accounting for biotic factors.

Differential Heating

The phenomenon where the tropics are warmer due to concentrated solar radiation at the equator.

Coriolis Effect

The deflection of moving air and water caused by Earth's rotation, resulting in different wind patterns in each hemisphere.

Active Dispersal

Movement where individuals travel long distances themselves, like birds and whales.

Passive Dispersal

Movement relying on environmental factors or other organisms, such as seeds carried by animals.

Natural Selection

The evolutionary process where traits that are variable, heritable, and confer a selective advantage lead to population evolution.

Genetic Drift

A change in gene frequency due to random chance, more noticeable in small populations.

Bottleneck Effect

A sharp reduction in population size that limits genetic diversity.

Founder Effect

When a small number of individuals establish a new population in a new area.

Inbreeding Depression

A reduction in fitness due to breeding between genetically similar individuals.

Adaptation

A long-term genetic change in a population that results from natural selection.

Acclimation

A short-term, reversible adjustment by an individual to lessen environmental stress.

Water Balance

The calculation of a plant’s water intake and loss, achieving homeostasis when W_net = 0.

Thermal Balance

The calculation of heat exchanges in a plant, achieved through various thermoregulatory processes.

Countercurrent Heat Exchange

A mechanism where heat is transferred from warm blood to cool blood to maintain core body temperature.

Transpiration

The process by which plants lose water, critical for turgor pressure and nutrient transportation.

Potential Evapotranspiration (PET)

The maximum transpiration under unlimited water conditions, calculated based on temperature.

Actual Evapotranspiration (AET)

The actual amount of water transpired, limited by available precipitation.

Cavitation

The process where high tension causes air bubbles to enter plant tissue, often affecting tall trees.

C3 Photosynthesis

The standard pathway of photosynthesis, less efficient in hot conditions due to photorespiration.

C4 Photosynthesis

A process that spatially separates CO2 fixation to concentrate CO2 near the enzyme Rubisco.

CAM Photosynthesis

A mechanism that temporally separates CO2 reactions, opening stomata at night to conserve water.