Trait-based studies have become extremely common in plant ecology. Trait-based
approaches often rely on the tacit assumption that intraspecific trait variability (ITV) is
negligible compared to interspecific variability, so that species can be characterized by
mean trait values. Yet, numerous recent studies have challenged this assumption by
showing that ITV significantly affects various ecological processes. Accounting for ITV may
thus strengthen trait-based approaches, but measuring trait values on a large number of …