Plant functional traits and the entangled phenotype

Integrated phenotypes consist of multiple traits with enough coordination within and across organs to result in viable individuals, which not only respond to the surrounding environment but also modify it in myriad ways. It is the individual organisms that are the target of ecological sorting and evolutionary selection and the ones that affect other organisms, ecosystem properties and benefits and detriments to people.

These hardly controversial statements are at the basis of trait‐based plant functional ecology and evolutionary biology, and the notion of effect traits is arguably implicit in the concepts of extended phenotype, niche construction and indirect genetic effects developed in the context of evolutionary biology. Yet, the practices of trait‐based plant functional ecology and evolutionary ecology have remained largely disconnected. In addition, despite the abundant evidence of trait coordination at the whole‐organism level, an arguably important portion of trait‐based plant functional ecology is now focusing on isolated traits, response traits in particular.

Here, I revisit the concepts of specific response functions (SEFs) and specific effect functions (SRFs), previously developed in the context of trait‐based functional ecology, in the light of ‘genes to ecosystems’ approaches developed in evolutionary biology. I argue that SEFs can be fruitfully integrated with the concept of ‘extended phenotype sensu lato’, which relaxes the requirement of being heritable in the traditional sense or feeding back onto the fitness of the organism that bears the genes responsible for it.

I discuss connections and gaps between the bodies of literature on plant functional traits, phenotypic integration and ‘genes to ecosystems’ approaches and propose to explore an ‘entangled’ perspective: Within the integuments of a plant (or other organism), functional traits are coordinated in integrated restricted phenotypes. In addition, beyond their integuments, plants co‐determine their immediate environments via their SEFs. This extended phenotype sensu lato interweaves with those of co‐existing organisms of different species, co‐constructing and maintaining structures and microenvironments which can be conceived as joint multispecies extended phenotypes sensu lato.

Finally, I point to directions in which tighter links among these fields would be fruitful and a few ways to start incorporating the ‘entangled’ perspective in trait‐based plant functional ecology, nature stewardship and climate change mitigation and adaptation.