DendroSync: An R package to unravel synchrony patterns in tree-ring networks

• Published in: Dendrochronologia (Verona) Vol. 47; pp. 17 - 22
• Main Authors: Alday, Josu G., Shestakova, Tatiana A., Resco de Dios, Víctor, Voltas, Jordi
• Format: Journal Article
• Language: English
• Published: Elsevier GmbH 01.02.2018
• Subjects: algorithms; computer software; Dendrochronology; growth rings; heteroskedasticity; Mixed models; Spatial synchrony; temporal variation; Tree-ring networks; Spatial synchrony; Dendrochronology; Tree-ring networks; Mixed models
• ISSN: 1125-7865; 1612-0051; 1612-0051
• DOI: 10.1016/j.dendro.2017.12.003

Spatial synchrony refers to the presence of a common signal for a time-varying characteristic that, in dendrosciences, is shared among tree-ring chronologies from a particular area. Analysis and interpretation of synchrony patterns in tree-ring networks is currently limited by: (i) the requirement for flexible modelling of complex correlations and heteroscedastic errors and (ii) the availability of ready-to-use open software to fulfil this task. We present an R package (DendroSync) that facilitates estimating and plotting synchrony patterns for pre-defined groups. The package has been devised to work with traits derived from tree rings (e.g. ring-width), but other data types are also suitable. It combines variance-covariance mixed modelling with functions that quantify the degree to which tree-ring chronologies contain a common signal over a fixed time period. It also estimates temporal changes in synchrony using a moving window algorithm. The functionality and usage of DendroSync are illustrated using a simple example.