SLU news

Paul Kardol – new Professor in forest microbiology

Published: 24 January 2023
Portrait photo of a man outdoors. Photo.

Paul Kardol researches plant-soil interactions and ecosystem processes. The last ten years he has been investigating the subarctic tundra in northern Sweden and focused on questions related to global warming. On the 1st of February he will be the new Professor in Forest Microbiology at the Department of Forest Mycology and Plant Pathology at SLU.

Paul was born and grew up in the eastern part of the Netherlands, in a small town called Oosterbeek.

– I grew up surrounded by oak and beech forests, and heathlands that turn purple in autumn. So, nothing like the polders and tulips field that you find in the western part of the Netherlands. The highest point in the area where I am from is more than 100 meters above sea level, which, by Dutch standards, is almost alpine, says Paul.

Paul loves travelling, both far away and shorter trips closer to home. He is fond of baking, anything from cookies to cakes and sourdough bread. In winter, he likes ice skating or cross-country skiing when the ice is snow covered. Another passion is growing his own vegetables.

– It is truly amazing how fast things grow up during the short Umeå summer! It is also surprising to see the diversity of vegetables that can be grown at this latitude. Almost all veggies my family used to grow in the Netherlands do totally fine up here.

How does global change affect the ecosystem?

Much of Paul’s research is about plant-soil interactions and feedbacks and how those interactions and feedbacks regulate ecosystem processes, in particular carbon cycling.  

– In my current projects, we use a wide variety of approaches to explore how global change influences plant-soil biota interactions and ecosystem functioning in (boreal) forests and other high-latitude and high-altitude ecosystems.

– Specifically, we focus on the linkages between plant and soil communities and how these linkages may be modified or disrupted under global change. We do indoor microcosm experiments as well as large-scale observational studies along climatic gradients to make better predictions of ecosystem functioning under future global change scenarios. Elevational gradients are great for this type of studies. And fieldwork in mountainous areas is always fun!   

When do we reach the tipping point?

Today, there is little consensus on how the functioning of terrestrial ecosystems will change under projected scenarios of global warming, or when we will reach or surpass thresholds and tipping points.

– In theory, it should be possible to predict how ecosystem processes respond to global warming from the reordering of plant and soil communities, and the functional traits and physiological responses of their component species. But that is certainly not easy. There’s lot of scientific and logistical challenges. I hope that step by step, we can make progress.

– For about ten years now, I have been working in the subarctic tundra in northern Sweden focusing on questions related to global warming. In this project, we use cross-disciplinary approach to advance our knowledge of how non-linear temperature responses transcend different levels of ecological organization. This sounds quite complicated and challenging, and it is! We basically try to better understand how and when global warming affects ecosystem carbon cycling.

Equality – not only about gender representation

Paul’s immediate goal as a professor at SLU is to create a work environment where people of all backgrounds feel comfortable and appreciated.

– This applies both to my research group as well as to teaching. SLU is working hard to improve the gender balance. That is great, but equality is not only about equal gender representation. To reach SLU’s ambitious vison, I believe there is more work to do when it comes to other aspects of diversity: enriching diversity and inclusion in terms of race, ethnicity, (dis)abilities, sexual orientation, socioeconomic status, and geographic region is much needed.

– There is a lot of evidence that diverse groups are more creative, innovative, and better problem solvers than less diverse groups, says Paul.

Nematodes and soil food webs

Paul studied biology at Utrecht University, specializing in landscape ecology. After this, he worked one year as an ecologist at the consultancy agency Royal Haskoning. Paul did his PhD research at the Netherlands Institute of Ecology (NIOO-KNAW) and got his degree from Wageningen University. His PhD research focused on plant and soil community assembly in secondary succession on ex-arable land.

– I was particularly interested in soil nematodes and soil food webs. My PhD was a combination of applied restoration ecology, field experiments, and more detailed plant-soil feedback experiments in the greenhouse. I still like greenhouse studies!

From Knoxville to Umeå

After his PhD, Paul started as a post-doc at the University of Tennessee in Knoxville.

– Here, I worked with Professor Aimee Classen on a multi-factorial global change experiment. Soon after I started in Tennessee, I got a fellowship from Oak Ridge National Lab where I worked as a staff scientist.

– After that, I moved to Sweden to work at SLU in the Department of Forest Ecology and Management in Umeå. At SLU, I started as a post-doc working with Professor David Wardle on a variety of projects all related to aboveground-belowground interactions and feedbacks.

– Half of the work was based in northern Sweden while the other half was based in temperate forests in New Zealand. Later, I have also worked on projects along long-term successional chronosequences in Australia. A bit more recently, I got funding to work on the role of mosses and moss food webs in driving carbon and nitrogen cycling in boreal forests.

Increased collaboration within SLU

Paul is looking forward to building new connections with the microbial researchers in the Department of Forest Mycology and Plant Pathology.

– So many new opportunities! This is not a short-term goal, but it is something I hope will build and grow with time.

– I will also stay connected to the Department of Forest Ecology and Management where I have been working since autumn 2009. In this role, I would like to build stronger connections between the two departments. For example, from a scientific point-of-view, there is not really a good reason why ‘forest microbial ecology’ is separated from ‘forest ecology’, and a good understanding of microbial ecology can probably help in transitioning towards more sustainable and climate-smart forest management.


Paul Kardol - Associate Professor
Department of Forest Ecology and Management
Swedish University of Agricultural Sciences