The files contain the data used in Flury et al. "Soil and climate-dependent ingrowth inference: broadleaves on their slow way to conquer Swiss forests" submitted to the scientific journal Ecography, 2023. The data stored here were derived from the Swiss NFI1-4 and the already available data of NFI5 until the end of 2022. The raw data from the Swiss NFI can be provided free of charge within the scope of a contractual agreement (http://www.lfi.ch/dienstleist/daten-en.php). The files 'Data Figure 2' to 'Data Figure 6' are publicly available and contain the data used to produce the figures from the manuscript "Soil and climate-dependent ingrowth inference: broadleaves on their slow way to conquer Swiss forests". The R code which enables the reproduction of these figures is available in 'R-source.zip'. The analysis of this data was done with the statistical software R (R version 4.2.2).