Le lundi 22 septembre 2025, Arpita VERMA présentera l'examen en vue de l’obtention du grade académique de Docteur en Sciences (Collège de doctorat en Sciences spatiales) sous la direction de Louis FRANCOIS. 

Cette épreuve consistera en la défense publique d’une dissertation intitulée :

« Assessment and future projection of climate change impacts on terrestrial ecosystem productivity and carbon balance using satellite/model approach  ».

Le Jury sera composé de :

Mme M. GREGOIRE (Présidente), Mme et MM. L. FRANCOIS (Promoteur), A. GOBIN (KULeuven), E. HALLOT (ISSeP), A. HAMBUCKERS, E. MAHIEU (Secrétaire), C. REYER (Potsdam Institute for Climate Impact Research).

Summary

Forests and grasslands are central to Europe’s carbon balance, biodiversity, and climate resilience. Yet both ecosystems are increasingly affected by climate change and land-use transitions, which determine how much carbon they can store, how efficiently plants use water, and how well they can withstand droughts. In Wallonia, Belgium, where forests cover more than half the territory, understanding these dynamics is essential for sustainable land and forest management.

This research developed a high-resolution simulation framework that integrates satellite-based land cover maps, species trait information, and regional climate projections within the CARAIB Dynamic Vegetation Model. The framework reconstructed ecosystem functioning from 1980 to 2020 and explored trajectories until 2070 under contrasting climate (RCP2.6 and RCP8.5), land-use, and management scenarios.

The results show that forests have generally accumulated carbon over recent decades, while grasslands, though highly productive, are more vulnerable to heat and drought stress. Conservation and afforestation scenarios enhanced carbon storage and ecosystem resilience, but these gains diminished under severe climate change. Adaptive forest management strategies, particularly thinning and regeneration, improved water-use efficiency and drought resilience for most species. Species responses diverged markedly: alder (Alnus glutinosa) maintained strong resilience, while poplar (Populus nigra) and Scots pine (Pinus sylvestris) proved highly sensitive in unmanaged, high-emission futures.

By introducing species-level resilience indicators and combining land-use and management pathways with climate projections, this thesis provides new insights into carbon dynamics, water-use efficiency, and drought adaptation. Its findings offer a robust scientific basis for land-use and forest policies that aim to sustain carbon storage, biodiversity, and resilience in temperate regions under accelerating climate change.

Lien public de la soutenance

Numéro de réunion : 829 9044 2760 
Code secret : 260627