Biology of Poa annua in a temperate zone golf putting green (Agrostis stolonifera/Poa annua). II. The seed bank.
The seed bank of a golf green was monitored for 2 years by identifying germinants in core samples. The seed populations contained 24 species of which only 4 occurred in the above-ground population. All species were abundant in the region and some were widespread. The main component of the seed bank was Poa annua. P. annua numbers fluctuated from a minimum of 30 000 seeds m-2 during autumn and winter, to a spring maximum of 210 000 seeds m-2. Agrostis stolonifera, with about 3000 seeds m-2, was the next most abundant species. Most of the P. annua seed bank was transient and germinated during spring and early summer. The persistent part of the seed bank probably derived from the same plants that produced the transient population. Its persistence is attributed to dormancy enforced or induced by seed burial. Much of the P. annua in the above-ground population was replaced annually from the transient seed bank. The persistent seed bank presumably enables P. annua to colonize any open areas created by disturbances in the green.