pin-frame(point frame) A device for obtaining a quantitative estimate of vegetation cover. Pin-frames are typically made from lightweight wood, aluminium, or plastic and comprise a cross-bar with pin-holes supported on legs of adjustable height. The pin-frame is set up so that the cross-bar sits above the vegetation to be sampled. Pins are lowered through the pin-holes and the plants hit by the pin-tips are recorded. Where the vegetation is of variable height, records of top-cover (the first plant encountered by the pin) and bottom-cover may be taken. The pin diameter used will affect the results and must be standardized for comparative work.

pin-frame A device for obtaining a quantitative estimate of vegetation cover. Pin-frames are typically made from light-weight wood, aluminium, or plastic and comprise a cross-bar with pin-holes supported on legs of adjustable height. The pin-frame is set up so that the cross-bar sits above the vegetation to be sampled. Pins are lowered through the pin-holes and the plants hit by the pin-tips are recorded. Where the vegetation is of variable height, records of top cover (the first plant encountered by the pin) and bottom cover may be taken. The diameter of the pin used will affect the results and must be standardized for comparative work.