Effects on soil and alternatives for biological control of the invasive plant Carpobrotus edulis

Abstract

The invasive plant Carpobrotus edulis can alter soil properties through its necromass (chemically different from natives’). Depending on the accumulated necromass, C. edulis has contrasting effects on soil pH, leading to different effects on nutrient availability. Carpobrotus edulis alters the soil nitrogen cycle through changes in nitrogen fluxes that can limit nitrogen availability. Until now, potential agents for biocontrol of C. edulis had not been studied. The fungus Sclerotinia sclerotiorum can infect C. edulis, but with no long‐term consequences in greenhouse conditions. The insect Pulvinariella mesembryanthemi can reduce survival and growth of the plant. This insect was introduced accidentally in NW Spain, where its potential distribution roughly overlaps that of C. edulis, but its abundance may be restricted by weather conditions in winter, parasitism and predation. Worldwide introductions of P. mesembryanthemi seem to originate from one native population, and most of its genetic variability resides in its native area.