Transpiration — Science definition
Defined in 4 courses:
- Water passing through plants and entering the atmosphere as vapor. (Science 6: Matter, Energy & Earth Systems)
- Loss of water vapour through pores in leaves, which draws water up from the roots and returns much of a region's water to the air. (Life Science & Scientific Inquiry)
- The release of water vapor from tiny openings in plant leaves; combined with evaporation, it's called evapotranspiration. (Earth & Space Science)
- The release of water vapor from plant leaves into the air, a major part of the water cycle. (Life Science: Biology)
Where it is taught
- The Water Cycle: Pathways, Stores & Drivers — Water, Air, Weather & Climate, Science 6: Matter, Energy & Earth Systems, Grade 6
- Carbon, Water & Cycling Matter — Ecosystems, Matter & Energy, Life Science & Scientific Inquiry, Grade 7
- The Water Cycle — Atmosphere & Weather, Earth & Space Science, Grade 9
- Biogeochemical Cycles — Ecosystems & Conservation Decisions, Life Science: Biology, Grade 10
In use
Energy from the Sun evaporates water from oceans, lakes and soil, and plants release more through their leaves by transpiration.
The Water Cycle: Pathways, Stores & Drivers
Evaporation lifts it from surfaces to the air; transpiration does the same through the pores of plant leaves, and in a forest that is a large fraction of the total; condensation turns vapour back to liquid as air cools, forming cloud; precipitation returns it; and runoff carries it across the surface to rivers and the sea, while some soaks into the ground.
Carbon, Water & Cycling Matter
Plants add to the supply too, releasing water vapor through tiny pores in their leaves in a process called transpiration — combine the two and scientists call it evapotranspiration.
The Water Cycle
Questions using transpiration
Problem 1
- A cloud is simply a mass of visible water vapor.
- Every water particle follows one identical circular route.
- transpiration: Water passing through plants and entering the atmosphere as vapor.
- One illustrative result establishes every real condition and needs no further evidence.
Answer and explanation
transpiration: Water passing through plants and entering the atmosphere as vapor.
Water passing through plants and entering the atmosphere as vapor. 35 + 25 + 20 = 80 mm, so the listed terms match the input under the model. Increased storage is not an outgoing flow. If unrecorded groundwater entered or left, the account would need that transfer; balance here does not prove every real pathway was measured.
Taught alongside
- infiltration
- evidence
- system boundary
- uncertainty
- reservoir
- condensation
- runoff
- storage change
- evaporation
- precipitation
- biogeochemical cycle
- carbon cycle
- nitrogen fixation
- photosynthesis