In some parts New Zealand it has been suggested that stands of U. europaeus facilitate the regeneration of native forest trees. Its presence results in some soil acidification. Impact on humans and related activities U. europaeus represents a fire hazard to private property. It invades watersheds which supply a substantial amount of drinking water. It is threatening agricultural and grazing lands.
Thickets are impenetrable to humans and have persistent spiny litter.
Control In Hawaii, temporary control was undertaken in the 1970s using 2,4-5 T. The ban of the herbicide and lack of funding ended the programme. No clear evidence is available but it appears that no equivalent species occur in any of the tropical regions invaded. Differences in status and ecology between invaded and native ranges Unusual case of a species with a temperate Atlantic distribution invading mountainous tropical regions as well as other temperate regions. However in all reported cases both in native and invaded ranges U. europaeus regeneration is highly favoured by the production of microsites by large hoofed mammals, particularly cattle. Differences in seedbank have been found between temperate regions.