The time is now ripe for ecologists and evolutionary biologists together to tackle a huge and important new challenge: mapping plant species effects on ecosystem functions onto the Tree of Life. This new research agenda is now tractable because of major recent advances in (i) screening plant species world-wide for the traits that support these functions, as well as in our understanding of how these traits support these functions; (ii) genetic screening and bioinformatics to build huge molecular plant phylogenies; and (iii) the comparative methods tools to analyse traits and phylogenies together. Understanding the evolutionary dynamics of traits related to biogeochemical cycling requires concerted research activity at a range of different phylogenetic scales, from analyses that consider data from all land plants to micro-evolution and other sources of intraspecific variation. This effort also requires study of the different plant organs involved in carbon and nutrient uptake, processing and transport, including the coordination between them. This overall effort should reveal (i) which lineages are associated with fast and which with slow turnover of carbon and nutrients (and water); (ii) how they are associated with fast versus slow turnover in terms of the traits involved; (iii) when in evolutionary history key transitions between fast and slow occurred; and (iv) what were and are the consequences of such variation in plant carbon and nutrient traits and turnover rates for past, present and future ecosystem functioning and services. Here, we introduce seven papers that together help set up this research agenda, each at a different phylogenetic level and resolution, and for different plant organs. Recent studies have begun to reveal evolutionary patterns in traits that matter to carbon and nutrient cycling for other groups of organisms, such as decomposing fungi and macrodetritivores and herbivorous animals. Ultimately such studies will all help towards the goal of mapping effects of organisms on biogeochemical cycling onto the entire Tree of Life. © 2014 British Ecological Society.