KA’AETÉ TECH LAB • VPD

Climate you can touch.

Air temperature, relative humidity and leaf temperature belong together. Change one variable and you change vapour pressure around the leaf. Here you can explore that yourself.

What happens?

RH upAt the same temperature, actual vapour pressure rises. The difference with the leaf becomes smaller and VPD falls.
Warmer airAt the same RH, actual vapour pressure rises, but so does possible saturation vapour pressure. What the plant experiences also depends on leaf temperature.
Cooler leafSaturation vapour pressure at the leaf falls. With a large difference from warm, humid air, the leaf surface can move toward condensation.
Why does it matter?VPD is a physical driving force behind transpiration, but plant response also depends on light, airflow, root water, species and growth stage.

Experiment

26 °C
80 %
24 °C
0.00 kPa

VPD

MICROCLIMATE • WHY ONE NUMBER IS NOT ENOUGH

One cabinet. Multiple climates.

A sensor tells you what happens exactly where it sits. Ten centimetres away a leaf may be cooler, air may be calmer and local humidity may be higher. KA’AETÉ therefore works with climate zones, not one climate number.

At the topMore light, usually warmer and more air movement.
Between leavesShade and still air can raise local RH.
Forest floorCooler, darker and strongly influenced by wet substrate.
Above waterEvaporation directly links the aquatic and aerial climate.
Educational illustration of tropical microclimate
AIR MOVEMENT

Ventilation is more than ‘air in, air out’.

Moving air mixes heat and moisture, but too much flow can dry local zones. Leaves, wood and walls constantly reshape airflow.

Tropical leaves and plant structure
LEAF TEMPERATURE

A plant does not feel only air temperature.

Light warms leaves; transpiration can cool them. A leaf can therefore differ from the nearby air sensor — and local vapour pressure changes with it.

Tropical stream in a humid environment
WATER & EVAPORATION

The aquarium changes the world above it.

An open water surface continuously feeds water vapour into the air. Temperature, airflow and exposed surface determine how much.

Tropical vegetation across different light layers
LIGHT & SHADE

Every new plant changes the system.

A larger canopy catches more light, casts shade, slows air and evaporates water. The microclimate evolves as KA’AETÉ grows.

Climate is a network, not a slider.

Temperature, RH, leaf temperature, light, airflow and water availability influence one another. The VPD tool shows one part; the living cabinet will show what happens when everything moves at once.

← Back to KA’AETÉ