SHIFT: How does a shift in forest tree species composition affect soil organic carbon storage in ancient forests of Wallonia

SHIFT: How does a shift in forest tree species composition affect soil organic carbon storage in ancient forests of Wallonia: site conditions, biotic interactions, and reversibility

Internal reference number: 25/30-154
Start date: 01/10/2025
End date: 30/09/2030

Partners

PI (spokesperson)
Pr. Dr. Quentin Ponette
Université catholique de Louvain – UCLouvain
Earth & Life Institute – ELI

Co-I 1
Pr. Dr. Frédérik De Laender
Université de Namur – UNamur
Research Unit in Environmental and Evolutionary Biology – URBE

Co-I 2
Pr. Dr. Monique Carnol
Université de Liège – ULiège
Integrative Biological Sciences – InBioS

Aims of the Coordinated Research Project

As in many countries worldwide, Wallonia has witnessed a conversion of semi-natural ancient forests to coniferous forests, some of which have been subsequently restored by planting indigenous broadleaved species. Understanding the effects of these consecutive conversions and restorations on soil organic carbon (SOC) storage, soil biodiversity, and ecosystem functioning is of paramount importance, as unconverted ancient forests may serve as benchmarks for assessing the effects and reversibility of changes in tree species composition on SOC storage and functioning in other similar systems. 

The general objective of SHIFT is therefore to gain a mechanistic understanding of how shifts in tree species composition affect SOC storage, soil biodiversity, and ecosystem function. To test the generality of these effects, we will deploy a sampling design with clusters of unconverted ancient forests, converted ancient forests and restored broadleaved forests that captures a variety of soil conditions, coupled to a modelling approach. 

The project will address the following specific objectives: 

(1) Understand the ecological and biogeochemical mechanisms driving SOC storage and soil biodiversity in unconverted ancient forests along a gradient of soil properties; 

(2) Examine how forest conversion affects these mechanisms, to understand and predict the consequences of forest conversion for SOC storage and soil biodiversity; 

(3) Unravel the consequences of soil biodiversity shifts for SOC storage and overall ecosystem function through integrative statistical analyses and carbon budgeting; 

(4) Understand the relationships between soil microbial and faunal diversity and functioning, SOC storage, and overall ecosystem function; 

(5) Use ecological models to study the dynamic behaviour of soil ecosystems to test transitions between unconverted, converted, and restored ecosystems.

The research team

Quentin Ponette is co-leading the Forest science team, hosted within the Earth and Life Institute (ELI) and the Environmental Sciences pole (13 professors, ca 100 researchers, ca 18 technicians, 1 secretary, 3 accountants). His research interests focus on the functioning of forest ecosystems, in terms of stand dynamics and biogeochemistry. He is currently supervisor or co-supervisor of 3 post-doc researchers, 7 PhD researchers and 1 research assistant, 2 of which could more directly contribute to the ARC project. With respect to the field work and sample pre-treatments, the project will benefit from the technical team available at the pole ‘Environmental sciences’ of the ELI (4 Full-Time persons), and at the Forest science team (1.5 EFT). Regarding the chemical analyses, Q. Ponette is a member of the ELI Mineral and Organic Chemical Analysis platform (MOCA), which has all the required analytical equipments, technicians and expertise.

Frédérik De Laender is Professor of Ecology and Director of the Research Unit in Environmental and Evolutionary Biology (URBE) at the University of Namur, Belgium. URBE brings together 41 researchers and 7 technicians with complementary expertise in understanding environmental impacts across multiple levels of biological organisation, from individual organisms and populations to communities and ecosystems. The unit integrates expertise in physiology, ecology, and evolutionary biology, providing a broad interdisciplinary environment for studying how organisms and ecological systems respond to environmental change. Within URBE, the De Laender lab currently comprises eight PhD researchers, one postdoctoral researcher, and one technician. The group has strong expertise in theoretical and experimental community ecology, with a particular focus on species interactions, biodiversity, community dynamics, and responses to environmental change. Members of the lab will contribute intellectually to the ARC project through scientific discussions, methodological expertise, and exchanges throughout the project, providing a stimulating research environment and a broad range of complementary expertise.

Monique Carnol heads the Laboratory of Plant and Microbial Ecology (LEVM, InBioS, University of Liège), which has long-term experience in forest soil ecology, linking tree species, soil microbial communities, nutrient cycling and carbon dynamics, as well as long term monitoring (soil & water) in forested catchments. LEVM is part of the InBioS research unit (Integrative Biological Sciences), with a multidisciplinary expertise from the molecular level to complex ecological systems, and technology platforms for molecular analyses, sequencing, bioinformatics, and chemical and biogeochemical analyses. Within this unit, the lab (currently 3 PhD researchers, 1 scientist, 1 technician) has in-house facilities for soil & water physicochemical analyses, microbial biomass and activity measurements (including MicroResp), DNA extraction and soil mesofauna extraction. ULiège participates as an associated partner, with its contribution funded externally. Within SHIFT, the team brings the soil biological perspective, with horizon-resolved analyses of microbial communities and functions across ancient, converted and restored forest stands.

Theses defended in the context of the Coordinated Research Project

Interacting effects of soil conditions and stand composition on SOC storage following conversion-restoration of ancient forests
Eloi Dilbeck
PhD thesis in progress
PhD supervisor: Quentin Ponette, Monique Carnol

Dynamic Modeling of Carbon Processing and Soil Microbiome Responses to Forest Tree Species Composition
Marie Grosse Holthaus
PhD thesis in progress
PhD supervisor: Frederik De Laender

Activities organised as part of the Coordinated Research Project

No activities at this stage of the project.

Publications in connection with the Coordinated Research Project

No publications at this stage of the project.

Contact points in UCLouvain

Pr. Dr. Quentin Ponette
Promoteur, Principal Investigator (spokesperson/coordinator)
Earth & Life Institute – ELI
Email address: quentin.ponette@uclouvain.be

Dr. Hugues Titeux
Postdoc sur ressources extérieures
Earth & Life Institute – ELI
Email address: hugues.titeux@uclouvain.be

Isabelle Vankeirsbilcke
Comptable en charge du suivi administratif du projet
Earth & Life Institute – ELI
Email address: Isabelle.vankeirsbilcke@uclouvain.be