The soil seed bank under nasella tussock infestations at Boschberg

Abstract

Nassella tussock (Stipa trichotoma Nees.) has a high annual production of seeds per plant. The total seed bank of all plants counted under a dense nassella infestation varied between 50 000 and 100 000 seeds m⁻² surface area (5 cm deep) of which more than half were nassella. Seeds were recovered from soil samples by wet-sieving, chemical flotation and aspiration. Burning of the dead organic material on the soil surface destroyed about 20% of the nassella seeds present in the top layers, suggesting that this treatment could become a useful part of a control strategy.