How can functional traits be used to direct ecological restoration?

One of the greatest challenges for ecological restoration is to identify which species will establish, co-exist, and perform the desired suite of services to re-establish ecosystem function. As recent work has shown that traditional functional group classifications (e.g., growth form,legumes) are not reliably linked to ecosystem function, focusing on functional 'traits' of species rather than functional 'groups' may be a more promising approach to restoring native communities. Identifying the functional traits (any physiological, morphological or phenological trait that influences plant fitness) of candidate species may elucidate which species are likely to succeed in a given system as well as their influence on ecosystem function. Few studies have explicitly examined functional traits, functional complementarity or functional redundancy in the context of ecological restoration. Functional redundancy may be particularly important to the success of restoration efforts under continued anthropogenic disturbances, including the introduction of invasive species, changes in fire regime, and changes in abiotic factors. Applying the concept of functional traits to ecological restoration requires (1) characterizing functional traits, (2) identifying the rate-limiting or important functions of the system, and (3) evaluating the factors that may alter the restoration trajectory.  Here, I focus on characterizing functional traits. Specifically, I present functional trait data pertaining to resource use efficiency in invasive and native species in Hawaiian systems to demonstrate how an understanding of functional traits may direct restoration.