The direction of carbon and nitrogen fluxes between ramets changes during ontogeny under simulated competition for light

Resource sharing is universal among connected ramets of clonal plants, and is driven both by the developmental status of ramets and resource gradients. Aboveground competition forms spatial light gradients, but the role of resource sharing in such competition is unclear. We examined translocation of resources between mother and daughter ramets of Agrostis stolonifera under light heterogeneity throughout ramet ontogeny. We labelled ramets by 13C and 15N to estimate bidirectional translocation of the resources at three developmental stages of daughters. Besides, we compared final biomass of integrated and severed ramets to estimate the effect of integration on growth. Young developing daughters were supported by carbon, whereas nitrogen was only translocated towards daughters at the beginning of rooting, regardless of the light conditions. Shading of mothers was a major determinant of resource translocation between developed ramets, with carbon being preferentially moved to daughters from...