Geology

Xylem

Biology

Electrical conduit

Engineering

Geotechnical engineering

Ecology

Earth science

Programming language

Constant (computer programming)

Plant life

Computer science

Botany

Hydrology (agriculture)

Environmental science

Mechanical engineering

Proceedings of the National Academy of Sciences

Significance For most of its path through plant bodies, water moves in conduits in the wood. Plant water conduction is crucial for Earth’s biogeochemical cycles, making it important to understand how natural selection shapes conduit diameters along the entire lengths of plant stems. Can mathematical modeling and global sampling explain how wood conduits ought to widen from the tip of a plant to its trunk base? This question is evolutionarily important because xylem conduits should widen in a way that keeps water supply constant to the leaves as a plant grows taller. Moreover, selection should act on economy of construction costs of the conducting system. This issue is ecologically important because it helps suggest why climate change alters vegetation height worldwide.

The Widened Pipe Model of plant hydraulic evolution