Data from: 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 shaded mothers while nitrogen translocation being limited from daughters to shaded mothers. Surprisingly, absolute amounts of translocated resources did not decline through development. Growth of daughters was enhanced by integration regardless of the shading.
Apparently, A. stolonifera maximizes the resource translocation pattern which enables it to spread from unfavourable habitats rather than compensate for light heterogeneity among ramets.

克隆植物相连分株间普遍存在资源共享现象，该现象同时受分株发育状态与资源梯度调控。地上竞争可形成空间光照梯度，但资源共享在这类竞争中的作用仍不明确。本研究以匍匐翦股颖（Agrostis stolonifera）的母株与子株为对象，探究了光照异质性环境下贯穿分株个体发育全程的资源转运过程。本研究通过碳13（¹³C）与氮15（¹⁵N）标记分株，在子株的三个发育阶段下评估资源的双向转运情况。此外，本研究通过对比克隆整合（clonal integration）与切断连接的分株的最终生物量，评估了克隆整合对植株生长的影响。处于发育早期的子株可获得碳源供给，而氮素仅在生根初期向子株转运，且不受光照条件影响。母株受遮阴是成熟分株间资源转运的主要调控因子：遮阴母株的碳源会优先转运至子株，而氮素从子株向遮阴母株的转运则受到限制。令人意外的是，转运资源的绝对总量并未随分株发育而减少。无论母株是否受遮阴，克隆整合均可提升子株的生长水平。综上，匍匐翦股颖通过优化资源转运模式，更倾向于从不良生境中扩散扩张，而非通过分株间的资源共享补偿光照异质性带来的影响。