Clonal integration in Ludwigia hexapetala under different light regimes

Abstract

a b s t r a c tPhysiological integration among ramets of invasive plant species may support their colonization and spread in novel aquatic environments where growth-limiting resources are spatially heterogeneous. Under contrasting light conditions, we investigated how clonal integration influences growth, biomass allocation and morphology of Ludwigia hexapetala, an emergent floating-leaved macrophyte that is highly invasive in a range of wetland habitat types. In aquatic mesocosms, stolons of offspring ramets were either connected or severed from parent plants, with the pairs exposed to homogenous or heterogeneous combinations of sun or 85% shade. Morphological traits of all ramets were strongly influenced by light environment, and low light availability decreased plant growth, regardless of integration status. Allocation patterns varied with light regime; shaded plants increased allocation to leaf biomass while sun plants allocated more resources to belowground growth. Offspring ramets integrated with parents produced more biomass, suggesting a fitness advantage through integration. However, parent ramet performance declined with stoloniferous integration; integrated parents produced fewer ramets and allocated more resources to belowground biomass. For most response variables measured, there was no significant interactive effect between light treatment and integration, although parents growing in the shade attached to an offspring in the sun increased root mass ratio. The ability to establish and spread into new environments is a key trait of invasive plants, and physiological integration of resources may improve the establishment of juvenile ramets across variable light environments during early colonization. Physiological integration in patchy light environments may contribute to the invasiveness of L. hexapetala.Published by Elsevier B.V.

Clonal integration facilitates spread of Paspalum paspaloides from terrestrial to cadmium‐contaminated aquatic habitats

“…; Glover et al . ), a recent meta‐analysis showed that it generally has no significant costs (Song et al . ).…”

“…; Glover et al . ), we can speculate that established ramets of amphibious clonal plants in terrestrial habitats can support young ramets to initially establish in aquatic habitats ( e.g . wetlands) heavily contaminated with Cd.…”

Nutrient addition does not increase the benefits of clonal integration in an invasive plant spreading from open patches into plant communities

“…In nature, environmental conditions are usually spatially heterogeneous (Glover et al ; Wang et al ). One potential benefit of clonality is that ramets, connected by belowground rhizomes or aboveground stolons, can share resources and signals, thereby increasing the growth and competition of clonal plants in numerous environments with heterogeneous distribution of light, water, nutrients and competitors (Stuefer et al ; Yu et al ; Song et al ; You et al ; Roiloa et al ; Wang et al ).…”

Survival and Growth of Epiphytic Ferns Depend on Resource Sharing

“…One strategy by which clonal plants cope with environmental heterogeneity is physiological integration, i.e., the capacity to share resources among interconnected ramets (Hutchings and Wijesinghe, 1997 ; Herben and Suzuki, 2001 ; Song et al, 2013 ; Roiloa et al, 2014 ; Dong et al, 2015 ). Physiological integration enables parent ramets to support offspring ramets (Matlaga and Sternberg, 2009 ; Oborny and Hubai, 2014 ; Roiloa et al, 2014 ; Glover et al, 2015 ) and ramets growing in favorable conditions to support those in unfavorable conditions (Roiloa et al, 2007 ; Xu L. et al, 2012 ; Kui et al, 2013 ; Tuya et al, 2013 ; Cornelissen et al, 2014 ; Luo et al, 2014 ).…”