TRANSPORT OF CARBON AMONG CONNECTED RAMETS OF EICHHORNIA CRASSIPES (PONTEDERIACEAE) AT NORMAL AND HIGH LEVELS OF CO₂

Abstract

The floating, stoloniferous plant, Eichhornia crassipes, has high rates of productivity and rapidly invades new sites. Because the transport of carbon among connected ramets is known to increase the growth of clonal plants, we asked whether there is intraclonal carbon transport in E. crassipes. Because net photosynthesis of E. crassipes is significantly higher at high levels of atmospheric CO 2 , we also asked if high CO 2 can change patterns of carbon transport in ways that might modify clonal growth. We exposed individual ramets within groups of connected ramets to 14C0 2 for 15-45 min and measured the distribution of 14C in the group after 4 days of growth at 350, 700, 1,400, or 2,800 ILl I-I CO 2 , At 350 ILl I-I CO 2 , a parent ramet exported approximately 10% ofthe 14C that it assimilated to its first rooted offspring ramet. The offspring exported a similar percentage of the 14C it assimilated toward the parent; two-thirds of this 14C was retained by the parent, and one-third moved into new offspring of the parent. In all ramets, imported carbon moved into leaves as well as roots. At the higher levels of CO 2 , the percentage of assimilated carbon exported from a parent ramet to the leaf blades of its first offspring was lower by half. High CO 2 had little other effect on carbon transport. E. crassipes maintains bidirectional transport of carbon between ramets even under uniform and favorable environmental conditions and when external CO 2 levels are very high.

Strategies of resource sharing in clonal plants: A conceptual model and an example of contrasting strategies in two closely related species

“…Our results showed zero net translocation of carbon in homogeneous conditions, as did the previous study on A. stolonifera (Duchoslavová & Jansa, 2018). Interestingly, low amounts of carbon were still exchanged in both directions in some plants under homogeneous conditions, which was observed before in Eichhornia crassipes (Alpert et al, 1991). Persistent directed translocation of carbon occurred only under heterogeneous conditions, consistent with previous findings (Saitoh et al, 2002;Wang et al, 2021).…”

Allocation of Biomass and Carbohydrates in Waterhyacinth (Eichhornia crassipes): Pond-Scale Verification.

“…Stembases are also a storage point for carbohydrates in waterhyacinth, where free sugars are converted to starch. Stolons are active conduits of carbohydrates which are freely shared among parent and daughter plants (Alpert, Warembourg, and Roy 1991), allowing the spread of the waterhyacinth mat through the production of new daughter plants.…”

Invasive alien plants benefit more from clonal integration in heterogeneous environments than natives

“…For native plant species, clonal integration has been repeatedly shown to facilitate establishment of newly produced daughter ramets (Hartnett & Bazzaz, ; Dong & Alaten, ; Touchette et al ., ), to increase growth of ramets in stressful habitats (Stuefer et al ., ; Alpert, ; Roiloa et al ., ), and to enhance fitness of the whole clone (Hellstrom et al ., ; Song et al ., ; Chen et al ., ). Other studies have shown that clonal integration can also greatly increase performance of invasive alien plant species (Roiloa et al ., ; Xu et al ., ; Wang et al ., ), including some of the world's worst invasive alien plant species such as Eichhornia crassipes (Alpert et al ., ), Alternanthera philoxeroides (Wang et al ., ; Yu et al ., ) and Spartina alterniflora (Xiao et al ., ). A recent meta‐analysis examined the relationship between the effect of clonal integration and measures of the degree of invasiveness (number of regions and references) around the world of 60 clonal plant species (Song et al ., ).…”