Physiological integration increases the survival and growth of the clonal invader Carpobrotus edulis

Abstract

Clonal growth seems to be a common trait for many of the most aggressive invasive plant species. However, little research has been conducted to determine the role of clonality in the successful invasion of new areas by exotic species. Carpobrotus edulis (L.) N.E. Br. is a mat-forming succulent plant, native to South Africa that is invasive in coastal dunes of Australia, New Zealand, USA and Southern Europe. Although Carpobrotus edulis is a clonal plant, there is no information on the role of clonality for the invasion by this species, therefore the objective of this study was to test whether or not physiological integration improves the performance of C. edulis invading coastal sand dunes. To do that, a 6-month field experiment was designed in which the stolon connections between the apical ramets and the C. edulis mats were severed to prevent physiological integration. This treatment was applied to ramets growing under high and low competition with the native species. Apical ramets with intact stolon connections were used as control. Integration improved the survivorship and growth of apical ramets, both in high and low competition. Connected ramets showed a more pronounced increase of clonal growth (estimated as stolon length) during the experimental period and a higher total biomass and number of ramets at the completion of the experiment. In terms of survivorship, the benefit of integration was greater under high competition. Physiological integration can therefore be considered an important factor in the invasiveness of C. edulis, both in open space and in direct competition with the native plants.

Body size and clonality consequences for sexual reproduction in a perennial herb of Brazilian rupestrian grasslands

“…Clonality can also improve the plant fitness since it may offer a connection between mother and daughter ramets (Roiloa et al, 2010). This connection is very important in rupestrian grasslands because it may enhance survival of ramets (Coelho et al, 2008a).…”

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

“…Most of the studies have been focused on the benefits of physiological integration (Song et al, 2013b;Wang et al,. 2008;Yu et al, 2009) for clonal invaders, and recent studies explicitly conducted with C. edulis have reported benefits of clonal integration at physiological and morphological level (Roiloa et al, 2016(Roiloa et al, , 2014a(Roiloa et al, , 2014b(Roiloa et al, , 2013(Roiloa et al, , 2010 …”

“…Recent studies have been conducted to determine the importance of clonal integration (i.e. resource sharing between connected modules of the clone via stolons) in the expansion of C. edulis (Roiloa et al, 2014a(Roiloa et al, , 2014b(Roiloa et al, , 2013(Roiloa et al, , 2010. However, the role of clonal structures as storage organs and their potential contribution to the expansion of this invader has not yet been investigated.…”

Effect of rosette size, clonality and spatial distribution on the reproduction of Vriesea carinata (Bromeliaceae) in the Atlantic Forest of Paraná, southern Brazil

“…The absence of spatial structure in the distribution of plants sharing the same vegetative traits indicates that plants more distantly located have more similar vegetative traits (related to size) than those growing closer. This may be due to the uniform environment where the plants are growing or to the physiological integration of clones buffering the negative effects of microhabitats (Roiloa et al 2010), and resulting in similar-sized plants despite spatial/environmental variation. On the other hand, V. carinata has spatial structure associated with reproduction, since plants close to each other were similar in terms of number of flowers, fruits and seeds.…”

“…Clonal reproduction assures the persistence of local populations by skipping sterility or a lack of pollinators (Reitz 1983;Sampaio et al 2002). In clonal plants, parental and daughter ramets are physiologically integrated (Pitelka & Ashmun 1985), which results in the transfer of resources that improves clonal growth and survival (Roiloa et al 2010). Clonality, in turn, may also increase flower production (Demetrio et al 2014).…”