Don't leave me behind: viability of vegetative propagules of the clonal invasive Carpobrotus edulis and implications for plant management

The capacity of succulent plants to create new invasive focus starting from disconnected plant fragments involves severe difficulties in the management of invaded areas. In the case of the succulent stoloniferous Carpobrotus edulis, clonality further difficults land restoration since management practices usually fragment and outspread vegetative propagules. In order to contribute to a better management of this highly invasive species, we explored fragment viability during the first month after disconnection. We hypothesized that period after separation from maternal clumps and propagule size, both influence the capacity of C. edulis to establish and develop new vegetative structures. With this objective, we separate apical fragments with two different sizes that were sown under greenhouse conditions after a sequence of storing time. We further examined morphological and physiological attributes as survival, length growth and biomass, FW/DW ratio, relative water content and leaf hydration, osmolarity and fluorescence. Biochemical parameters were also included through the measurement of phenol and tannin content together with photosynthetic pigments (chlorophyll (a,b) and carotenoids) and derived ratios. After 2 months, apical propagules did not show signs of morphological, physiological or biochemical deterioration with increasing storing periods. Propagules showed improved or at least similar performance after storing for longer periods, with slight or no differences between different sized propagules in morphological or physiological values as indicated by the absence of enhanced leaf water status, the maintenance of photosynthetic efficiency (high F-v/F-m values) and the stability in photosynthetic pigments content. Our results indicate that the growth of C. edulis propagules is not significantly constrained during the first month after disconnection, no matter the size of apical fragment considered. As a final remark, we consider that our results are important to ameliorate and efficiently monitor and manage invaded areas where C. edulis had been recently eliminated.