Effects of clearing treatment on seed banks of the alien invasive shrubs Acacia saligna and Acacia cyclops in the southern and south-western Cape, South Africa.
Abstract
Data are presented for 10 fynbos sites with stands aged 25-80 yr subjected to various clearing treatment (felling, piling, burning) over 12 yr with repeated control of germinants at some sites. Seed populations of both species declined significantly with burning after 1 yr but not thereafter; seed banks of A. cyclops, but not A. saligna, were reduced by shrub felling alone after 1 yr. Because enough seeds always remained in the soil after treatment to regenerate new stands, subsequent treatments to kill seedlings are essential.