Sundependent

Sundependent is an adjective used to denote dependence on sunlight for energy, growth, development, or activity. It is most commonly encountered in ecology and botany to describe organisms or processes that require solar radiation as a primary energy source.

In contemporary scientific writing, the standard form is typically sun-dependent or sunlight-dependent. Sundependent as a closed form is rarer and may appear in older literature, in glossaries, or in more general, non-technical writing. The term highlights the role of the sun as an essential driver of biological or ecological processes, rather than a secondary or incidental factor.

Examples of sun-dependent systems include photosynthetic plants and algae that rely on sunlight to power photosynthesis, diurnal animals whose activity follows day-night cycles, and ecosystems where solar energy sustains the base of the food web, such as shallow coral reefs with photosynthetic symbionts. The concept can be used to contrast with non-sun-dependent processes or organisms, such as chemoautotrophs or deep-sea communities that derive energy from chemical sources, or shade-tolerant species that persist under limited light.

See also related concepts such as sun dependence, photosynthesis, photoperiodism, and diurnal rhythms.