PUU: an Excel macro

Tree ring data provide detailed information on arboreal growth variability and reactions to management and environmental changes. Such dendrochronological datasets may be quite large containing timeseries from tens to hundreds or thousands of trees and require software or programmed script to be processed and analyzed. This paper presents an Excel macro designed for production of age-standardized (i.e. detrended) tree-ring data from ‘raw’ measurement series. The macro is globally applicable to cross-dated tree-ring data. The modules included in the macro focus on methods retaining the long-timescale growth variability and the original scale of raw growth measurements, which may both be lost when the traditional tree-ring standardization methods are applied to dendrochronological datasets. The macro allows to combine the methods transforming the raw data into dimensionless indices (including the family of regional-curve-standardization, power-transformation or signal-free methods) with age-standardization and back-transformation methods resulting in processed tree-ring datasets with original growth units. These methods are anticipated to be beneficial for forest research where estimation of absolute rather than relative change in growth is commonly demanded. Familiarity of Excel by the researchers and students is expected to allow wide accessibility to the macro.