Depth-dependent degradation of archaeological timber in an arid burial environment: a multi-indicator case study

Archaeological timber preserved in arid burial environments undergoes degradation processes distinct from those of waterlogged wood, with deterioration primarily driven by abiotic factors. This study investigates depth-dependent degradation in Larix potaninii components from a Tang Dynasty tomb using layer-by-layer sampling combined with multi-indicator analysis, including physical, chemical and microstructural measurements. Results reveal pronounced surface deterioration characterised by reduced density, increased moisture uptake, decreased cellulose crystallinity and disrupted cell wall structures, while inner regions are comparatively better preserved. Consistent trends across multiple indicators enable differentiation of degradation states within structural components. These findings provide quantitative insight into degradation gradients in arid archaeological wood and provide a preliminary basis for evaluating consolidant penetration and developing targeted conservation strategies.