Vegetation Response after Removal of the Invasive Carpobrotus Hybrid Complex in Andalucía, Spain

Abstract

We evaluated the ecological success of the manual removal of Carpobrotus species, a putative hybrid complex of a South African perennial mat-forming plant, by comparing treated, noninvaded, and invaded plots across coastal Andalucía in southern Spain. As a measure of the management effectiveness, we quantified the density of Carpobrotus seedlings and resprouts in treated plots one year after treatment. Response of the plant community to removal was assessed by com- paring native species richness, cover, diversity, and species composition among treatments. Removal greatly reduced to a great extent Carpobrotus density. However, successful control will require repeated hand-pulling treatments. Treated plots had a significant increase in species richness, especially annual plants, compared to invaded plots, but both had the same native plant cover and diversity. We found similar species composition between removal and noninvaded plots, indicating that revegetation is not necessary. Long-term monitoring is necessary to determine whether these observed patterns of community response are transient or stable through succession.