Leaf Energy Balance and Temperature Regulation

Vocabulary flashcards covering key terms related to leaf energy balance and temperature regulation in plants.

Temperature

A measure of mean molecular speed (i.e., energy level); heat moves in response to temperature differences.

Heat Content

A measure of total kinetic energy based on mass, temperature, and specific heat capacity.

Temperature Coefficient (Q10)

A measure of how reaction rates change with a 10 °C increase in temperature; typically around 2.

Endotherms

Organisms that primarily use internal factors (e.g., metabolic heat) to regulate body temperature; includes mammals and birds.

Ectotherms

Organisms that primarily use external factors to regulate body temperature; includes most plants, reptiles, and insects.

Homeotherms

Organisms that maintain a constant body temperature; commonly referred to as 'warm-blooded'.

Poikilotherms

Organisms whose body temperature varies with ambient environmental temperatures; commonly referred to as 'cold-blooded'.

Energy Budget

The net balance of incoming and outgoing energy (heat) in organisms.

Absorptance

The fraction of solar radiation absorbed by a leaf.

Reflectance

The fraction of solar radiation reflected by a leaf.

Transmittance

The fraction of solar radiation transmitted through a leaf.

Latent Heat of Vaporization

The amount of heat absorbed for a substance to change from liquid to vapor.

Transpiration

The process by which plants lose water vapor, influencing leaf temperature.

Stephan-Boltzman Law

A law that describes the amount of longwave radiation emitted by an object based on its temperature.

Wien’s Law

A law stating that warmer objects emit shorter wavelength radiation than cooler objects.

Convective Heat Exchange

The transfer of heat through the movement of air.

Leaf Absorptance along an Aridity Gradient

Variation in leaf absorptance levels in different moisture conditions among species.

Longwave Radiation

Radiation emitted by all objects above absolute zero, typically from surrounding objects.

Leaf Optical Properties

Characteristics of leaves that determine how much solar radiation is absorbed, reflected, or transmitted.