fellingdater: Tree-ring dating and estimating felling dates of historical timbersThe fellingdater package provides a suite of functions for
dendrochronological and dendroarchaeological analysis, covering a
workflow from tree-ring data processing and crossdating, up to
the estimation and reporting of felling dates. Originally designed
to assist dendrochronologists in inferring felling dates from dated
tree-ring series with partially preserved sapwood, the package has been
expanded to include a workflow for tree-ring dating, analysis, and
visualization.
You can install the latest release of fellingdater from
GitHub or
R-universe:
# install.packages("pak")
pak::pak("ropensci/fellingdater")
or
# install.packages("remotes")
remotes::install_github("ropensci/fellingdater")
trs_* functions):Data generation and preparation: Create synthetic datasets with
trs_pseudo_rwl(), or read and prepare real data with read_fh(),
trs_select(), trs_remove() and trs_trim().
Crossdating analysis: Perform crossdating with trs_crossdate()
and set end dates for the tree-ring series with trs_date_end().
The statistical measures in the crossdating procedure include:
t-values according to Hollstein
(1980) and Baillie
& Pilcher (1973) transformation
procedures (trs_tho()and trs_tbp())
percentage of parallel variation, including (Semi-)Synchronous
Growth Changes (SGC and SSGC, Visser
2020), and Gleichläufigkeit
(Buras & Wilmking
2015, Eckstein &
Bauch 1969, Huber
1943) and associated
significance level (Jansma
1995) (trs_pv())
correlation measures, r Pearson and t-values (trs_tSt())
Visualization: Display crossdating results with
trs_plot_dated(), or individual series with trs_plot_rwl()
sw_* functions):The package’s primary focus is estimating felling dates from accurately dated tree-ring series with preserved sapwood (sw). When the bark/cambial zone (waney edge) is absent, the preserved sapwood rings can be used to establish a date range for the felling event, allowing researchers to report an interval in which the actual felling date (fd) likely falls.
This procedure can be applied to individual series as well as to a collection of related timbers.
Individual series: Estimate felling date ranges from tree-ring series with preserved sapwood.
Group analysis: Combine multiple samples assumed to be felled simultaneously for enhanced precision.
Probability densities: Work with sapwood probability distributions and create summed probability densities that reflect dynamics in felling date intensity.
The package workflow progresses logically through:
In the following example the combined felling date range for a set of five dated tree-ring series is computed:
library(fellingdater)
## a data set where all series have partially preserved sapwood:
sw_example1
#> series last n_sapwood waneyedge
#> 1 trs_01 1000 5 FALSE
#> 2 trs_02 1009 10 FALSE
#> 3 trs_03 1007 15 FALSE
#> 4 trs_04 1005 16 FALSE
#> 5 trs_05 1010 8 FALSE
sw_combine(sw_example1, plot = TRUE)
The light grey distributions shows felling date probability densities for each individual series, while the dark grey distribution represents the combined estimate for a common felling date.
The sapwood model used in the example above to estimate the felling date range, was published by Hollstein (1980):
sw_model("Hollstein_1980", plot = TRUE)
The package provides comprehensive tools for the tree-ring analysis workflow:
set.seed(1234)
trs <- trs_pseudo_rwl(n_series = 5, series_length = c(100, 150),
end_date = c(2000, 2025), related = TRUE,
prefix = "series_")
trs_plot_rwl(trs,
color = c("tomato3", "navyblue", "forestgreen", "purple", "orange")
)
series <- trs |> trs_select("series_1", trim = TRUE)
reference <- trs |> trs_select("series_2")
cd_results <- trs_crossdate(series, reference, min_overlap = 50,
sliding = TRUE, top_n = 5, rank_by = "t_Ho")
#> | | | 0% | | | 1% | |= | 1% | |= | 2% | |== | 3% | |=== | 4% | |=== | 5% | |==== | 6% | |===== | 7% | |===== | 8% | |====== | 8% | |====== | 9% | |======= | 10% | |======== | 11% | |======== | 12% | |========= | 13% | |========== | 14% | |========== | 15% | |=========== | 15% | |=========== | 16% | |============ | 17% | |============= | 18% | |============= | 19% | |============== | 20% | |=============== | 21% | |=============== | 22% | |================ | 22% | |================ | 23% | |================= | 24% | |================== | 25% | |================== | 26% | |=================== | 27% | |==================== | 28% | |==================== | 29% | |===================== | 29% | |===================== | 30% | |====================== | 31% | |======================= | 32% | |======================= | 33% | |======================= | 34% | |======================== | 34% | |======================== | 35% | |========================= | 36% | |========================== | 37% | 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#>
#> Processing crossdate results...
cd_results
#> series length first last reference ref_first ref_last overlap r_pearson
#> 1 series_1 127 1888 2014 series_2 1894 2008 115 0.77404006
#> 2 series_1 127 1831 1957 series_2 1894 2008 64 0.18945685
#> 3 series_1 127 1876 2002 series_2 1894 2008 109 0.04366101
#> 4 series_1 127 1861 1987 series_2 1894 2008 94 0.14617934
#> 5 series_1 127 1850 1976 series_2 1894 2008 83 0.11888267
#> t_St t_BP t_Ho sgc ssgc sgc_p glk glk_p
#> 1 13.00 9.39 10.41 64.0 11.4 0.002610835 69.7 2.305114e-05
#> 2 1.52 1.94 2.22 47.6 15.9 1.296761417 55.6 3.740628e-01
#> 3 0.45 2.43 1.93 50.0 11.1 1.000000000 55.6 2.460349e-01
#> 4 1.42 1.17 1.85 50.5 10.8 0.916970020 55.9 2.514796e-01
#> 5 1.08 2.01 1.81 54.9 12.2 0.374098327 61.0 4.551633e-02
series_dated <- trs_end_date(series, 2014)
trs_plot_dated(series_dated, reference,
zscore = TRUE, pv_highlight = TRUE)
Explore the package capabilities through our documentation:
Get started
vignette
This package was developed during the analysis of a large data set of tree-ring series originating from medieval timber constructions in Bruges (Belgium). The results of this study were published in Dendrochronologia.
Please cite these papers when using the fellingdater package:
Kristof HANECA
2024. fellingdater: a toolkit to estimate, report and combine felling dates derived from historical tree-ring series. Journal of Open Source Software, 9(97), 6716. https://doi.org/10.21105/joss.06716
Kristof HANECA
https://doi.org/10.1016/j.dendro.2020.125773
The fellingdater package builds on established crossdating algorithms
from dendrochronology literature. It also draws inspiration from
established R-apackages like dplR.
fellingdater
Gmińska-Nowak B., Raczkowski J., Chlebus E. & Heussner K.-U. 2025: Cistercian heritage in Pelplin, Poland. Dendrochronological dating of the covers of medieval codices, Dendrochronologia 94, 126439.https://doi.org/10.1016/j.dendro.2025.126439
Weitz A., Haneca K. & Hoffsummer P. 2025: Estimating sapwood counts for historical oak timbers from Brussels, Belgium (13th–18th century), International Journal of Wood Culture 5, 1–16. https://doi.org/10.1163/27723194-bja10038
Altman J., Altmanova N., Fibich P., Korznikov K. & Fonti P. 2025: Advancing dendrochronology with R: an overview of packages and future perspectives, Frontiers in Ecology and Evolution 13, 1593675. https://doi.org/10.3389/fevo.2025.1593675
Haneca K., Debonne V., Davies D., McCarroll D. & Loader N.J. 2025: Oxygen isotope dendrochronology allows dating of historical timbers across a wide geographical region, Dendrochronologia 89, 126283. https://doi.org/10.1016/j.dendro.2024.126283
Haneca K. 2024: fellingdater: a toolkit to estimate, report and combine felling dates derived from historical tree-ring series, Journal of Open Source Software 9.97, 6716. https://doi.org/doi.org/10.21105/joss.06716
Haneca K. & De Groote K. 2024: Ieper - De Meersen. Deel 5. Houten grafkisten, tonnen en gebruiksvoorwerpen: dendrochronologie, typologie en houtonderzoek, Onderzoeksrapporten agentschap Onroerend Erfgoed 330, Brussel. https://doi.org/10.55465/CNJU8492
Domínguez-Delmás M., Schroeder H., Kuitems M., Haneca K., Archangel S., van Duin P. & Piena H. 2023: A stepwise multidisciplinary approach to determine the date and provenance of historical wooden objects, Journal of Cultural Heritage 62, 430–440. https://doi.org/10.1016/j.culher.2023.06.023
Haneca K., Debonne V. & Hoffsummer P. 2020: The ups and downs of the building trade in a medieval city: Tree-ring data as proxies for economic, social and demographic dynamics in Bruges (c. 1200–1500), Dendrochronologia 64, 125773. https://doi.org/10.1016/j.dendro.2020.125773
Please report any issues or bugs here: https://github.com/ropensci/fellingdater/issues.
Get citation information for fellingdater in R typing
citation(package = 'fellingdater').
Please note that the fellingdater package is released with a
Contributor Code of
Conduct.
By contributing to this project, you agree to abide by its terms.