Are ecophysiological adaptive traits decoupled from leaf economics traits in wetlands?

Abstract

Abstract Wetland plants have developed a suite of traits, such as aerenchyma, radial oxygen loss and leaf gas films, to adapt to the wetland environment characterised by, for example, a low redox potential and a lack of electron acceptors. These ecophysiological traits are critical for the survival and physiological functioning of wetland plants. Most studies on these traits typically focus on a single trait and a single or few species at the time. Next to these traits, traits of the leaf economics spectrum (LES) that reflect resource acquisition and allocation in plant species have also been frequently measured in wetlands. However, the performance of the LES has rarely been examined among wetland plants. Both suites of traits are critical for—but affect different aspects of—wetland plant functioning and survival. The interactions between them, potentially causing synergies or trade‐offs, reflect wetland plant strategies to simultaneously deal with stress tolerance and resource utilization, and have ramifications for the functioning of wetland ecosystems. Based on a literature review and quantitative analysis of available data, we provide evidence suggesting that LES and ecophysiological traits may be decoupled (e.g., for root porosity and radial oxygen loss vs. leaf nitrogen) or coupled (e.g., for iron tolerance vs. specific leaf area) in wetlands, depending on the trait combination concerned. This rather complex relationship between wetland adaptive traits and LES traits indicates that there can be multiple mechanisms behind the strategies of wetland plants. We further illustrate how adaptive and LES traits together contribute to wetland ecosystem functions, such as denitrification and methane emission. We highlight that both suites of traits should be considered simultaneously when applying trait‐based methods to wetland ecology.