2.5.2—Transect use

A line transect samples communities at fixed positions along a suspected gradient so biotic patterns can be compared with abiotic measurements.

Place quadrats at matched distances, record abundance or presence, and measure the relevant variable such as moisture, pH, salinity or light. Co-change supports a relationship but does not prove one cause.

Along a shore, algae cover falls as distance above water rises while immersion time is recorded at each quadrat.

A transect tests whether a species-distribution pattern tracks the proposed environmental gradient rather than distance alone.

A kite diagram shows pattern, not causation; confounding variables and sampling bias still matter.