BAI BAI bias – uncertainty in basal area increment estimates

Basal area increment (BAI) is increasingly used in tree-ring studies, whereby BAI is mostly estimated based on increment cores while assuming circular growth patterns. In reality, however, tree stems are mostly characterized by a certain degree of eccentricity, posing the question how accurate BAI estimates from cores are. In a recent study, to which Marieke van der Maaten-Theunissen and Ernst van der Maaten contributed, and which was published in Dendrochronologia, the accuracy of BAI calculation methods was evaluated using a simulation approach. It was found that bias in calculated BAI values is strongly influenced by the number of cores taken, with a dramatic decrease from one to four cores.