Trait-based ecology has changed the way plant ecologists study community-level processes, among other advances through the description of the plant economics spectrum, resulting from the consistent correla-tion across spatial scales of functional traits related to resource investment. Between species, these trait correlations have revealed trade-offs in the way available resources are allocated in a given set of environ-mental conditions, and that these trade-offs impact community assembly rules and ecosystem processes. Within species however, uncertainties remain around the importance of intraspecific trait variation (ITV), and its potential upward repercussions on higher-order processes. As a matter of fact, ITV has been observed to impact species distribution and the biotic interactions within species. With rapidly changing climatic conditions, ITV might help in determining species response to adverse conditions, and to infer an ecosystem’s tolerance to these conditions. Coastal wetlands are at the forefront of climate change, with short environmental gradients of inundation frequency and salinity that are bound to shift in the following decades. In an ex situ experiment mimicking estuarine constraints of salinity and inunda-tion frequency, we have observed substantial shifts in intra-specific growth and resource allocation strate-gies of isolated plant individuals without competition. Across the two interacting stress gradients, the plant species’ traits related to resource acquisition correlated to reveal the acquisition – conservation strat-egies of the plant economic spectrum. Each of the three species displayed distinctive ITV, highlighting the importance of individual variability, that should be taken into account when studying community-level responses to stress gradients.
