Fossil wood reveals climate stress and fungal decomposition in Late Triassic (Norian) forests in central Europe

Abstract

Late Triassic forests in Central Europe developed under a seasonal sub‐tropical climate while the supercontinent Pangea was breaking up. Although permineralized fossil wood from this interval is abundant, its palaeoclimatic and palaeoecological significance has so far remained largely unexplored. Here we present a detailed anatomical, taphonomic and dendrochronological study of an Agathoxylon log and associated wood remains collected from the Late Triassic Löwenstein Formation (Norian, Keuper) at the locality Neuenplos in Bavaria, southern Germany. Tree height reconstruction and longevity estimation indicate that the tree reached c . 43 m in height and may have survived for more than 500 years, placing it within an old‐growth Keuper forest. More than 20 successive growth rings, including biennial narrow rings, yield a mean sensitivity of 0.67, reflecting inter‐annual variability driven by alternating wet–dry seasons typical of a semi‐arid sub‐tropical setting; false rings record episodic water stress during the growing season. Fungal decay patterns (white rot and brown rot) demonstrate post‐mortem saproxylic activity. Together, these data reconstruct a dynamic ecosystem in which large conifer trees endured fluctuating climate stresses while providing substrate for diverse fungal decomposers, thereby shedding light on nutrient cycling processes in Triassic continental forests. Our results provide a robust palaeoclimate archive and highlight the importance of fossil wood in reconstructing ancient forest resilience, with implications for understanding vegetation dynamics under contemporary climate change.