Soil biodiversity is enormous, with millions of species and billions of individuals forming one of the most complex biological community on Earth. With the advent of high throughput molecular methods, we can quantify patterns of soil biodiversity better than ever and find new, exciting ways to look into terrestrial ecosystem structure and functions. And yet, we still have a poor  understanding of the processes that structure ecosystems. We know, for example, better than ever how many species live at a given place but are, too often, missing the processes that bring species together and drive their future population trajectories, and the consequences of these processes on the cycling of matter and fluxes of energy.

In this talk, I will offer an overview of our current  understanding of the processes that structure soil biodiversity. I will also touch on the methods we need to progress on the pathway from patterns to processes with a focus on the relative roles of selection (e.g., environmental filtering, biotic interactions) and stochastic factors (e.g., dispersal) on the community dynamics of soil bacteria, fungi, and microarthropods. I will explore how molecular tools can help us advance the state-of-the-art and discuss experimental platforms that will help us unravel the role of soil biodiversity in ecosystem processes.

Climate change and the depletion of fossil resources have urged the transition from a fossil-based to a bio-based society. In the bio-economy, lignocellulosic plant biomass can be converted to fermentable sugars. However, for the production of fermentable sugars from biomass, lignin, an aromatic heteropolymer, needs to be extracted from the biomass by costly pretreatments. Engineering of the amount and structure of lignin is an attractive strategy to improve the efficiency of biomass processing. Hence, significant research efforts have been devoted to unravel the lignin biosynthesis pathway and to investigate the effects of altering the expression of individual steps of this pathway on lignin amount and composition, and on biomass properties.

These studies have shown that lignin amount and composition can be altered and that biomass processing can be improved. We use Arabidopsis thaliana as a model to discover new genes of the lignin biosynthesis pathway. Genes that provide promising improvements in biomass processing upon their altered expression in this model system are then taken further for translational research in poplar and maize. Field trials have been established with GM poplar with modified lignin. These trials, established for a period of 8 years, show that field trials are an essential step in the translation of research towards applications.

Whilst the circular economy promises significant environmental, social and economic benefits, particularly in a context of sweeping climatic change, environmental deterioration and economic and financial crisis, in practice the ‘linear model’ still dominates the economic system. The uptake of circular economy models seems to be slower than expected. There may be several reasons for this, which range from cultural resistance, e.g. because its complexity  challenges the current neo-liberal thinking and its simplicity tenet, to the lack of adequate policy frameworks, the absence of specific financial instruments and the lack of specialist skills and competences.

The stakeholders involved in the economic processes, including policy makers and decisions makers, need simple frameworks that allow them to rethink the socio economic system. In our research, we tried to rethink the concept of the ‘circular economy’ through the prism of its relevance to its many stakeholders, ranging from public and private actors and mature and emerging industries to cities and regions, SMEs and multi-sectoral corporations. In particular, we developed a schematic modular framework, which breaks down the circular economy into fundamental building blocks and shows how these block are interconnected in relation to the multiplicity of stakeholders.

Such blocks may then be used by policymakers on the one hand and by decision makers on the other to progressively to transition the economic systems towards the circular economy. In particular, we used the framework to develop recommendations addressed to European policy-makers on how best to support such transition towards a circular economy in the EU.