Soil structure and moisture effects on biotic soil functions under different land use and climatic scenarios

Abstract

Soil structure and moisture regulate soil biotic activity and plant performance, yet their interactive roles in mediating ecosystem functioning under global change remain unclear. Using multi-year data from the Global Change Experimental Facility (GCEF), this thesis examines how soil structure and moisture shape soil biotic functions across contrasting land-use systems and climate scenarios. Integrating X-ray CT analyses with measurements of carbon fractions, nematode communities, roots, and soil moisture dynamics, the results show that land use consistently shapes soil microstructure, biotic interactions, and water-use strategies, whereas climate effects are subtle and mainly expressed during extremes through deep soil water legacy effects. Overall, this work highlights land use as the dominant driver of soil–plant–water interactions and emphasizes the need to integrate structural, biological, and hydrological processes to predict ecosystem responses under future climate change.