The Journal of Ecology editors are delighted to announce that Sandra Lavorel is our Eminent Ecologist for 2017. In recognition of her work, we have asked Sandra to select 10 of her most influential Journal of Ecology papers to make up a special virtual issue.
The final group of papers illustrates advances on my personal “Holy Grail”; aiming to explore how trait-based approaches can support the quantification of ecosystem services.
This ambition dates back to the Holy Grail response-effect framework (Lavorel & Garnier 2002), but took a long time to realise step by step from the investigation of trait responses, to trait effects on ecosystem functioning, and eventually the ability to model ecosystem services across landscapes (or regions).
The first of the three papers (Lavorel et al. 2011) is the outcome of this long process, once again focused on subalpine grasslands and clearly the fruit of long-term research at a single site. Here, following standard protocols and carefully tested approaches for the large-scale assessment of plant functional composition, we were able to collect data on soils, plant communities and their traits, and multiple ecosystem properties for a set of 56 plots distributed across management types, landscape sectors and altitude.
Using statistical modelling, we then obtained models of ecosystem properties associated with ecosystem services valued by local stakeholders that were based on plant traits and soil parameters. Knowing variations of these parameters according to management and altitude across the landscape allowed us to produce the first trait-based ecosystem service maps. Further, by analysing jointly the maps for multiple ecosystem services we were able to identify bundles (positive associations) and trade-offs (negative associations) between ecosystem services, as well as services that vary independently of each other, and can therefore be managed without mutual constraints.
The same data set indeed made it possible to go one step further and identify the functional underpinnings for ecosystem trade-offs and synergies (Lavorel & Grigulis 2012). Using once again the gradient from more intensively managed, more fertile to extensively managed, less fertile grasslands we showed using structural equation modelling how functional trade-offs at plant level, following the Global Spectrum of plant form and function (Diaz et al. 2016), scale up to ecosystem properties and ecosystem services. This type of understanding is critical because it shows very clearly what hard constraints the fundamental properties of organisms impose on ecosystems capacity to supply multiple ecosystem services, or conversely what opportunities exist given appropriate management to reconcile multiple ecosystem services.
Trait-based approaches to quantifying ecosystem effects and ecosystem services have been a blossoming endeavour, with increasing numbers of studies since our first attempts and the Special Feature of the Journal of Ecology published in 2013 (Lavorel, 2013).
Many questions still remain open (Garnier et al. 2016), for instance about the relative roles of the mass ratio hypothesis and functional complementarity, when to account for intraspecific trait variability, or to which extent trait-based approaches can be applied across trophic and interaction networks to predict ecosystem services.
I am very excited to see these approaches now being developed in other ecosystems and regions, and how they can be extended to larger scales, finally getting back to the initial objectives of plant trait research. This is made possible by the combination of large inter-site data sets and data bases in floristic composition (e.g. Violle et al. 2015) and plant traits (Kattge et al. 2011). New developing approached using remote sensing (Pettorelli et al. 2017) are also particularly promising.
You can read Sandra’s virtual issue on the journal website, or view the individual papers below.