%0 Research Notes %T A comparison of ash dating and moss-increment dating in Sphagnum hummocks %A Eustis, Deborah S. %A Tolonen, Kimmo %D 1990 %J Suo - Mires and peat %V 41 %N 2 %U http://suo.fi/article/9672 %X A comparison of two methods for dating recent ombrotrophic peat hummocks was made at three mires. For depths approximately below 10 cm, acid insoluble ash dating gave greater ages than moss-increment dating; for depths above 10 cm, the methods showed more similar ages. The moss-increment dates were assumed to be generally correct since there was a good correlation between several independent dating results and moss-increment ages at one of the study sites. Despite the declining accuracy of moss-increment dating with depth, it should be the method chosen for dating recent peat in areas where the assumption of constant acid insoluble ash deposition is invalid. Increment dating is practically useful only in the moss hummocks, except for when the moss stems have been compressed into a horizontal position. Keywords: Dating, mineral dust, peatlands, Sphagnum, surface peats