Effects of fragmentation and seawater submergence on photochemical efficiency and growth in the clonal invader Carpobrotus edulis

Abstract

Clonal plants are frequently affected by process of disturbance as fragmentation. The capacity of these fragments to survive and grow after disturbance has important implications for the expansion of clonal plants, and could have special consequences for the colonization of new environments by invasive clonal species. Stolon internodes of clonal plants represent important reserve organs. These storage structures can play a crucial role in the survival and re-growth of clonal plants after an event of disturbance. In this study we simulated physical disturbance by fragmentation of clones of the stoloniferous invader Carpobrotus edulis into ramets with short and long stolon lengths, and a subsequent event of seawater submergence and de-submergence. Ramets with long stolons showed a significantly higher total biomass than ramets with short stolons, supporting the idea that stolon length is related with the amount of reserves stored and with the benefit reported in terms of growth. Our results showed that the benefit of having long stolons was also important for clonal fragments that suffered a process of seawater submergence. Our study suggests that the use of stolon as a source of resources can represent a suitable mechanism for colonization of coastal sand dunes by the aggressive invader C. edulis