Soils house an overwhelming abundance and diversity of living (micro)organisms. In our research we examine how plants influence the soil they grow in, and how these changes influence other plants that grow later in the soil, and the insects on those plants. We study the mechanisms of these aboveground-belowground interactions under controlled conditions in greenhouses and growth chambers, but also in real field situations. Most of our work focuses on grassland ecosystems but we also study these interactions in horticultural soils. In collaboration with restoration practitioners we examine how we can improve the biodiversity and functioning of these grasslands, by using plants to improve soils or via soil inoculation.

More information about Martijn Bezemer

Together with a research team of PhD students and postdocs I study how soil legacy effects influence aboveground plant-insect interactions. We aim to understand how plants influence soil biota in the rhizosphere, and how these plant-soil effects via soil legacy effects, influence the growth and nutritional quality of other plants that grow later in the soil, as well as the aboveground insects on these plants. We examine which plant characteristics (plant traits) explain how plants influence the microbiome of the soil they grow in, and how plants respond to changes in soil microbiomes. We also study how soil microbial communities influence defense responses (induced systemic resistance) in aboveground plant parts, and how the insects that feed on these plants and their natural enemies respond to these changes in plants.

We study these soil legacy effects under controlled conditions with potted plants in greenhouses and in growth chambers, so that we can manipulate these aboveground-belowground interactions but we also examine plant-soil-insect interactions in field experiments, for example in restoration grasslands at the Veluwe area. It is extremely challenging to study these plant-soil insect interactions in entire grasslands but our work shows that even in such complex systems each plant individual creates its “own” local soil food web. In ongoing field experiments in grassland communities we examine, for example, how plant community traits influence the microbiome in the soil and how later growing plant and insect communities then respond to these changes. In another field experiment we examine how inoculation with soils (and microbiomes) collected from underneath plant communities with different traits steers later plant community development.

In our work, we focus on new scientific insights, as well as on making this fundamental knowledge applicable. We examine, for example, how soil inoculation, with living soil collected from another ecosystem or with watery suspensions that contain soil biota can speed-up nature restoration. In commercial greenhouses, we examine how we can improve the suppressiveness of soils against aboveground pests of the cutflower Chrysanthemum, an important ornamental crop in the Netherlands. We aim to develop soil inocula by making use of plant-soil feedback principles and microbiomes from natural soils.

Above-Belowground Interactions

For more information about current research, please check out the Above-Belowground Interactions Group Website.