Understanding Earth Critical Zone subsurface architecture: A perspective on the challenges and opportunities for lateritic landscapes

The Earth’s Critical Zone (CZ) encompasses the near-surface layer where rock, soil, water, air and living organisms interact to regulate the delivery of ecosystem services. Central to CZ functioning is its subsurface architecture, defined as the spatial distribution and connectivity of soil, sediment and weathered bedrock. This review examines the principal factors governing soil and regolith development, including climate, organisms, relief, parent material, time and anthropogenic disturbance, and their role in generating subsurface heterogeneity across landscapes. We then briefly explore the implications of subsurface architecture for rooting depth, water partitioning and landscape response to natural hazards. A brief overview of the principal tools used to characterise CZ subsurface architecture is also presented, including traditional approaches and more contemporary geophysical and remote sensing techniques that enable advanced understanding of subsurface structure and process interactions. Finally, we consider the opportunities and challenges associated with extending CZ science and subsurface architectural studies into lateritic landscapes. These deeply weathered systems remain comparatively underrepresented despite their hydrological and geomorphological importance and present distinct challenges related to their substantial depths and long-term chemical weathering. Greater integration of CZ frameworks into lateritic environments offers an important direction for future research aimed at improving landscape process understanding.