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DendroTools : R package for studying linear and nonlinear responses between tree-rings and daily environmental dataJernej Jevšenak,
Tom Levanič, original scientific article
Abstract: We introduce in this paper the dendroTools R package for studying the statistical relationships between tree-ring parameters and daily environmental data. The core function of the package is daily_response(), which works by sliding a moving window through daily environmental data and calculating statistical metrics with one or more tree ring proxies. Possible metrics are correlation coefficient, coefficient of determination and adjusted coeffi- cient of determination. In addition to linear regression, it is possible to use a nonlinear artificial neural network with the Bayesian regularization training algorithm (brnn). dendroTools provides the opportunity to use daily climate data and robust nonlinear functions for the analysis of climate-growth relationships. Models should thus be better adapted to the real (continuous) growth of trees and should gain in predictive capabilities. The dendroTools R package is freely available in the CRAN repository. The functionality of the package is demonstrated on two examples, one using a mean vessel area (MVA) chronology and one a traditional tree-ring width (TRW).
Keywords: dendroclimatology, daily climate data, running window, nonlinear modelling, tree-ring proxies, climate reconstruction
Published in DiRROS: 16.04.2018; Views: 2994; Downloads: 1874
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