Relation Between Success Rate and Sample Quantity in Dendrochronological Dating of Building Materials

Abstract

Optimizing sample quantity and quality improves cost-effective and less invasive dendrochronological investigations. Our study examined 3,831 trees, including 2,921 pine, 404 spruce, and 506 oak trees. Pine had a 79.2% success rate for dating, spruce 46.5%, and oak 67.8%. Success rates increased with more trees analysed, notably in the case of spruce. When 1–3 spruce trees were analysed, only 44% yielded dating, while 8 or more trees achieved a 91.6% success rate. For pine, success rates ranged from 89% to 98%, and oak achieved success rates between 64% and 100%, depending on the number of trees analysed. The number of annual rings also had a significant impact. For spruce with 31–60 rings, only 33% could be dated, while pine and oak had higher dateability percentages at 60.1% and 48.6%, respectively. With 91–120 rings, dateability improved to 87.7% for pine, 75% for spruce, and 72.6% for oak. We observed temporal variations in dated material availability, likely due to shifts in building material usage over centuries. This study enhances our understanding of factors affecting sample requirements for successful dendrochronological analysis. While specific results have local relevance, the underlying principles and challenges apply globally, encouraging meaningful discussions between clients and dendrochronologists.