Sprecher
Beschreibung
During the Late Triassic, forests in the Central European Basin developed under a seasonal subtropical climate. Although fossil wood from this interval is abundant, its paleoclimatic and paleoecological significance has so far remained largely unexplored. Here we investigate a silicified log and associated wood fragments from the Löwenstein Formation near Bayreuth in southeastern Germany. These fossils are assigned to Agathoxylon sp. based on araucarian radial tracheid pitting and araucarioid cross-field pitting, representing the first unequivocal record of this genus from the Bayreuth region. Height reconstruction using an allometric tree growth model from a trunk diameter of 0.65 m suggests that the source tree reached approximately 43 m, indicating tall, long-lived conifers and old-growth forest elements in the Norian landscape. More than 20 successive growth rings, including biennial narrow rings, yield a mean sensitivity of 0.67, reflecting interannual variability driven by alternating wet–dry seasons typical of a semi‑arid sub-tropical setting; false rings further record episodic water stress during the growing season. Anatomical evidence of both white-rot and brown-rot decay documents post-mortem saproxylic activity. Together, these data reveal 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 highlight the importance of fossil wood in reconstructing ancient forest resilience, with implications for understanding vegetation dynamics under contemporary climate change.