Environmental Data: Generalised stand descriptions in Switzerland

Description

The files refer to the data and R code used in Mey et al. "From small forest samples to generalised uni- and bimodal stand descriptions" (2021) _Methods in...

Citation

Mey, R., Stadelmann, G., Thürig, E., Bugmann, H., Zell, J. (2020). Generalised stand descriptions in Switzerland. EnviDat. https://www.doi.org/10.16904/envidat.197.

Resources

• Data Figures 2 and 4

  This csv file contains the data required to reproduce Figure 2 and Figure 4. * 'stand_type' states whether a row corresponds to NFI4 average summary statistics describing a generalised beech-dominated, spruce-dominated or an unspecified forest stand in Switzerland in its unimodal or bimodal form (e.g. 'beech.uni' refers to a generalised unimodal beech-dominated stand) * 'md' refers to the mean diameter * 'dq10' refers to the 10% quantile of the diameter * 'dq90' refers to the 90% quantile of the diameter * 'spr' refers to the spread between minimal and maximal diameter * 'nph' refers to the number of stems per hectare * 'o.qmd' refers to the overstorey quadratic mean diameter * 'rho.emp' refers to proportion parameter (rho) determined by breakpoint setting * 'ba' refers to the basal area per hectare * 'drel' refers to the relative diameter ('drel' = (d - min(d)) / (max(d) - min(d))) * 'temp' refers to the mean winter temperature (1988-2017, Dec-Feb) * 'dev' refers to the development stage of the stand (e.g. 'Young growth') * 'ftyp' refers to the potential climax forest type (e.g. 'Beech' refers to a beech-dominated stand) * 'str' refers to the stand structure * 'tillering' indicates whether the observed tree species on the NFI plot correspond to 'ftyp' ('TRUE') or not ('FALSE') * 'prodreg' refers to the Swiss production region (ecoregion) * 'fowner' refers to the forest ownership ('Public' or ' Private')

  Data Figures 2 and 4

• Data diameter modelling

  This rds file contains a list of 5085 data frames required to reproduce the uni- and bimodal diameter model. Each data frame comprises single-tree diameters ('dbh') and assigned representation factors ('repfa') at a single Swiss NFI4 plot. * 'dbh' refers to the diameter at breast height (130 cm) * 'repfa' refers to the representation factor used to scale up to one hectare

  Data diameter modelling

• Data species modelling

  This rds file contains a data frame with single-tree and stand data required to reproduce the species composition model: * 'clnr' refers to the plot number * 'spec' refers to the main tree species group (12 groups) * 'ba' refers to the basal area per hectare * 'nph' refers to the number of stems per hectare * 'drel' refers to the relative diameter ('drel' = (d - min(d)) / (max(d) - min(d))) * 'temp' refers to the mean winter temperature (1988-2017, Dec-Feb) * 'dev' refers to the development stage of the stand (e.g. 'Young growth') * 'ftyp' refers to the potential climax forest type (e.g. 'Beech' refers to a beech-dominated stand) * 'str' refers to the stand structure * 'tillering' indicates whether the observed tree species on the NFI plot correspond to 'ftyp' ('TRUE') or not ('FALSE') * 'prodreg' refers to the Swiss production region (ecoregion) * 'fowner' refers to the forest ownership ('Public' or ' Private')

  Data species modelling

• Script diameter and species modelling

  This R script can be used to derive the uni- and bimodal Weibull log-likelihood regression models (in short: uni- and bimodal model), the species composition model and the main results presented in Mey et al. 2021 using data from the fourth Swiss NFI ('data_NFI4_diameter_modelling.rds' and 'data_NFI4_species_modelling.rds') and the R functions stored in 'functions_diameter_modelling.R'.

  Script diameter and species modelling

• Functions diameter modelling

  This R file contains the functions used to produce the generalised diameter distributions in Mey et al. 2021.

  Functions diameter modelling