Flowering currant (ribes sanguineum) shrublands in the lower waitaki valley, south canterbury

Abstract

Flowering currant (Ribes sanguineum) is classified as a noxious plant in Waitaki County, South Canterbury. On the north bank of the Waitaki River it forms scrub-grasslands w1th the spiny shrub, matagouri (Discaria toumatou), and species of Coprosma, particularly on shady hill slopes and gullies. The stem diameters of flowering currant and matagouri were measured and the ages were determined from ring counts. There is a close positive relationship between stem diameter and age in the flowering currant. Most seedlings establish beneath matagouri bushes and although flowering currant can spread by suckering and layering, this is largely prevented by sheep and rabbit grazing. Most flowering currant bushes are more than 10 years old, and the apparent spread of this plant in recent years has resulted from the suppression of matagouri growth by flowering currant bushes. The flowering currant stands are self-perpetuating, but they are being slowly invaded by wind-dispersed adventive trees. Flowering currant does not threaten pastoral land in the lower Waitaki. © Crown copyright 1984.