Gregory VAN DER HEIJDEN
AgreenSkills session, year: 1st session, 2013
Receiving laboratory: Biodiversity and Ecosystem services in a Changing Climate, Sweden
Country of origin : France
Modelling nutrient cycling in forest ecosystems with the ForSAFE model: Testing the model with an in situ multi-isotopic tracing experiment
Many forest soils in France are acid and nutrient poor. In the context of global change, French forests endure increased external constraints which may be nutritional and/or silvicultural and/or climatic. These constraints may strongly impact the sustainability of nutrient-poor ecosystems. It is thus important to understand and quantify the processes which govern nutrient cycling in these ecosystems to better predict soil fertility changes and help forest managers make sound decisions to sustain these ecosystems. For this purpose, many forest nutrient cycling models have been developed in the past twenty years (ForSAFE, NuCM, MAGIC, etc.). At the European scale, the Lund University in Sweden has developed models for scientific and management use (PROFILE, ForSAFE) integrating soil properties, weathering rate calculation, atmospheric deposition, climate change and silvicultural practice change. However, many fluxes (atmospheric deposition, weathering) and processes (nutrient uptake by trees, nutrient recycling) are yet poorly quantified. These fluxes and processes are important in ecosystems on nutrient-poor soils where no flux, even small, may be neglected.
Simulation models are a synthesis of our knowledge and concepts of the functioning of forest ecosystem biogeochemistry. The reliability of model predictions depends on the capacity of the model to reproduce the fluxes and processes. During my PhD, I carried out an in situ multi-isotopic tracing experiment (26Mg, 44Ca, 15N and 2H) in a beech plot of the high resolution SOERE F-ORE-T experimental site (Breuil-Chenue, Burgundy, France). The main objective of my postdoctoral project is to test the ForSAFE model with the results from this experiment, thereby refine current nutrient cycling concepts and improve existing biogeochemical models.
After my engineering degree in forest management (2006-2009) at AgroParisTech-ENGREF in Nancy (France), I was very interested in the sustainability of forest soil fertility facing the 21st century changes: decreasing nutrient atmospheric deposition and increasing pressure of biomass harvest for environmental friendly fuels and materials. I decided to pursue my interests by carrying out a Master’s degree in soil science (2008-2009, MSc Thesis “Modelling the response of a fir tree stand on a base-poor soil in the Vosges Mountains (France) to atmospheric deposition and silviculture change”). I obtained a 5-year junior-scientist position “INRA-CJS” (2009-2014) for my PhD entitled “A multi-isotopic (26Mg, 44Ca and 2H) tracing experiment to better understand nutrient cycling in forest ecosystems” carried out at the Forest Ecosystem Biogeochemistry Lab (INRA Nancy, France). I am now carrying out a post-doctoral project as an Agreenskills fellow at Lunds Universitet in Sweden that aims to develop the ForSAFE biogeochemical numerical model to be able to simulate Mg and Ca isotope tracers in forest ecosystems. In July 2013, I obtained a permanent research scientist position (CR2) at the Forest Ecosystem Biogeochemistry Lab (INRA Nancy, France).
van der Heijden G, Legout A, Pollier B, Ranger J, Dambrine E (2014) The dynamics of calcium and magnesium inputs by throughfall in a forest ecosystem on base poor soil are very slow and conservative: evidence from an isotopic tracing experiment (26Mg and 44Ca). Biogeochemistry: 1-30
van der Heijden G, Legout A, Pollier B, Mareschal L, Turpault M-P, Ranger J, Dambrine E (2013) “Assessing Mg and Ca depletion from broadleaf forest soils and potential causes – A case study in the Morvan” Forest Ecology and Management 293(0): 65-78
van der Heijden G, Legout A, Pollier B, Bréchet C, Ranger J, Dambrine E (2013) “Tracing and modeling preferential flow in a forest soil — Potential impact on nutrient leaching” Geoderma 195-196(0): 12-22.
van der Heijden G, Legout A, Midwood A, Craig C-A, Pollier B, Ranger J, Dambrine E (2013) “Mg and Ca root uptake and vertical transfer in soils assessed by an in situ ecosystem-scale multi-isotopic (26Mg & 44Ca) tracing experiment in a beech stand (Breuil-Chenue, France)” Plant Soil 369, 33-45.
van der Heijden G, Legout A, Nicolas M, Ulrich E, Johnson D W and Dambrine E (2011) “Long-term sustainability of forest ecosystems on sandstone in the Vosges Mountains (France) facing atmospheric deposition and silvicultural change” Forest Ecology and Management 261, 730-740.
Gandois L, Nicolas M, van der Heijden G and Probst A, 2010, “The importance of biomass net uptake for a trace metal budget in a forest stand in north-eastern France” Science of The Total Environment 408, 5870-5877.
2013 DEMOLON fellow of the AFES (Association Française d’Etude des Sols) to attend the 10th Applied Isotope Geochemistry conference in Budapest, Hungry (September 22nd to 27th)
2013 Agreenskills fellow (outgoing fellowship) for a research project with Salim BELYAZID of Lunds Universitet in Sweden: Developing the ForSAFE model to simulate Mg and Ca isotope tracers in forest ecosystems.