High Variability and Multiple Trade-Offs in Reproduction and Growth of the Invasive Grass Cortaderia Selloana After Cutting

Abstract

[Abstract] The ability to balance the allocation of resources between growth and reproductionas a response to stress factors, can be an advantage for plants in disturbed environ-ments. Invasive alien plants (IAPs) often show high levels of phenotypic variability inresource allocation, a key trait that plays a crucial role in their success to invade newareas. Control management for IAPs must consider this capacity in the developmentof effective strategies. In this study, we performed continuous measures of leafgrowth and reproductive traits of Cortaderia selloana, an IAP of global concern, andapplied generalised linear models (GLMs) to evaluate trade-offs between vegetativegrowth, leaf composition and reproductive success at different cutting moments.Cutting moment, but not flowering, affected the length of the vegetative growthperiod (VGP) and average growth rate (AGR), and the interaction with floweringaffected AGR and final leaf length (vegetative growth total, VGT). Specific leaf area(SLA), leaf nitrogen (N) content and the isotopic value of δ13 C were affected by cut-ting, and N was also affected by flowering and the interaction with cutting time. Silicaalso showed a negative correlation with leaf carbon (C) depicting a trade-off betweenboth structural components. Cortaderia selloana successfully adapted its leaf growthand composition to cutting moment, but this was also modulated by flowering. More-over, the species is dioecious, and its response may differ between female and her-maphroditic plants. This suggests flexible trade-offs in resource allocation, thereforethe time for cutting must be precisely scheduled to suppress flowering.