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.

Temperate food forests have gained attention over the last decade because of their potential to contribute to restoration of biodiversity and carbon storage. So far scientific research has been limited to case studies and identifying socio-economic values. In this project, we aim to understand how food forestry affects belowground biodiversity and functioning (including carbon storage) compared to other types of land use (e.g., arable farming, grassland). We collect field observations and use controlled experiments. This project is part of a larger TKI program, where also aboveground biodiversity and earning models of food forests are investigated. For information see: https://www.wur.nl/nl/Onderzoek-Resultaten/Onderzoeksinstituten/Environmental-Research/Projecten/Wetenschappelijke-bodemvorming-onder-de-voedselbosbouw-1.htm

As a response to global climate change, which is putting increased pressure on most ecosystems, national and international agreements aim at creating forests that are productive, resilient to climate change, and that store carbon to mitigate global warming. However, these aims are being challenged by increased tree mortality rates and decreased tree growth rates in response to increased incidence of drought. The summer drought of 2018 alone resulted in 100 million m3 of dead trees in Europe, equivalent to a loss of approximately 3.5 billion euros wood.
Therefore, the challenge is to develop climate-smart forestry (CSF) in order to sustain or increase forest productivity, forest resilience and forest carbon storage under climate change. Currently, there is a lack of crucial insights into the effects of forest management on the growth and survival of trees, and on carbon storage in both trees and forest soils, particularly under increased incidence of drought. We test the hypothesis that CSF aims can be achieved via controlling stand density by applying intermediate levels of tree harvest intensity. The main aim of this proposed project is to quantify the effects of drought and management-controlled stand density on forest productivity, forest resilience, and carbon storage in trees and soils.