The goal of this project is to decipher the role of fungal denitrifiers in N2O production from soils under sustainable management practices. Here we apply mesocosms experiments combined with SIP and meta-omics approaches targeting the functional genes of N cycle. In addition, we design primers for fungal denitrifiers based on complete fungal genomes and soil metagenomics data.  

Understanding carbon cycling in soils is of vital importance, because it determines soil-climate feedbacks via balance of carbon between the soil and the atmosphere, as well as soil health. Soil communities play a key role in driving soil carbon cycling. Soil organisms degrade organic matter, which drives emissions to the atmosphere. At the same time they use carbon for their own growth and thereby determine the amount of carbon retained in soils and microbial biomass. Higher trophic levels of soil organisms may modify the activity and performance of soil microorganisms by feeding on them, as well as by changing abiotic conditions in the soil. As a result, they can strongly impact the role of microorganisms in driving carbon cycling and storage. How soil communities and trophic interactions between soil organisms drive carbon losses and gains in soils is still poorly understood. Therefore in my group, we focus on how soil communities drive soil carbon cycling. We pay specific attention to relationships between litter and decomposer communities in driving soil carbon cycling and to the role of higher trophic levels in modifying rates of carbon cycling. This is work is carried out in close collaboration with the Lejoly group.

In many ecosystems, human impacts have strongly altered the quantities and relative ratios of elements such as carbon, phosphorus, nitrogen. This may have important consequences, not only for the plants, but also for the animals that use these plants as food source. Animals need specific ratios of elements for their optimal growth, survival and reproduction. Deviations from these ratios (‘stochiometric mismatch’) may lead to substantial performance reductions with important ecological and microevolutionary consequences. In this project, we investigate how populations of zooplankton herbivores respond to and cope with both shortage and excess of critical elements in their diet, both from ecological and microevolutionary perspectives.

Vertebrate herbivores and nutrient deposition have a strong impact on the biodiversity and functioning of grasslands worldwide. Both factors have been changing rapidly over the last decades due to exctinction of herbivores, restoration of herbivore communities (e.g., rewilding) and enhanced nutrient inputs in natural grasslands via agriculture and fossil fuel combustion. In a global network of experiments we quantify how these changse impact on plant, soil and insect biodiversity, the cycling of nutrients and other functions in grassland ecosystems (https://nutnet.org/). At the NIOO, we coordinate the Dutch NutNet site, which is situated on the Veluwe.