stdTRW: stdTRW

In AgeBandDecomposition: Age Band Decomposition Method for Tree Ring Standardization

stdTRW

Description

To remove the influences of local site characteristics on tree growth, this function standardizes the tree-ring width series by dividing each tree-ring width of a particular series by the mean width of that series. In dendroclimatic studies, it is advisable to exclude the initial years or decades of growth (the first “age bands”, i.e., 1-10 and 11-20) as they are less likely to contain climatic signals rather than the influence of strong early-year growth competition within the tree stand (Mazza and Sarris, 2021; Sarris et al., 2007).

Usage

stdTRW(inTRW)

Arguments

inTRW

tibble. The first object resulting from the TRW_readExcel function.

Details

To export a tibble like the one below to an .xlsx file, you can use the writexl package:

mytibble <- stdTRW_df |>
  dplyr::group_by(year) |>
  dplyr::summarise(
    N_trees = dplyr::n(),
    mean_stdTRW = mean(stdTRW, na.rm = TRUE)
  )

writexl::write_xlsx(mytibble, path = "my_stdTRW_df.xlsx")

This will create an Excel file named my_stdTRW_df.xlsx in your current working directory. Please, check also the Examples section below for how to obtain stdTRW_df object.

Value

A tibble with the following columns: year, tree_code, TRW, meanTRW, and stdTRW. Together with additional columns of grouping variables based on age class.

References

Mazza, G., Sarris, D., 2021. Identifying the full spectrum of climatic signals controlling a tree species' growth and adaptation to climate change. Ecol. Indic. 130, 108109. https://doi.org/10.1016/j.ecolind.2021.108109.

Sarris, D., Christodoulakis, D., Körner, C., 2007. Recent decline in precipitation and tree growth in the eastern Mediterranean. Glob. Chang. Biol. 13 (6), 1187–1200. https://doi.org/10.1111/j.1365-2486.2007.01348.x.

See Also

TRW_readExcel, ABD

Other ABD functions: ABD(), TRW_readExcel()

Examples

inTRW_1 <- inTRW[[1]]

stdTRW_df <- stdTRW(inTRW_1)

stdTRW_df |>
dplyr::group_by(year) |>
dplyr::summarise(N_trees = dplyr::n(),
       mean_stdTRW = mean(stdTRW, na.rm = TRUE)) |>
       ggplot2::ggplot(ggplot2::aes(year, N_trees)) +
       ggplot2::geom_line()

AgeBandDecomposition documentation built on Aug. 8, 2025, 6:45 p.m.