DOI: 10.16904/envidat.197
title: 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 Ecology and Evolution_.
Generalised stand descriptions are coming from the simultaneous examination of samples that are representative for a specific target area (here, Switzerland) and link available information about forest stand attributes. They combine the modelling of uni- or bimodal diameter distributions and species compositions, i.e. the shares of stems of individual species. Generalised stand descriptions may be used to interpret tree species diversity, regeneration and harvest potentials on a plot-level basis, and to initialise forest models with representative stand data.
The data stored here were derived from the fourth campaigns of the Swiss National Forest Inventory (NFI). 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).
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The file 'Data Figures 2 and 4' is publicly available and contains the data used to produce the Figures 2 and 4 published in the paper.
The files 'Data diameter modelling' and 'Data species modelling' contain all the data required to reproduce the diameter and species model building. The access to these two files is restricted as they contain raw data from the fourth Swiss NFI, submitted to the Swiss law and only accessible upon contractual agreement.
The files 'Script diameter and species modelling' and 'Functions diameter modelling' are publicly available and provide the R code used to derive the generalised stand descriptions from the Swiss NFI data.
description: Resource Title: Data Figures 2 and 4
 Size: 744 bytes
 Format: text/csv
 URL: https://www.envidat.ch/dataset/f8fe4971-0538-4d8e-b866-8d1cfd4b1584/resource/2e6a5bbe-6836-47b2-86bb-be16ba2fe81e/download/data_figures_2_4.csv
 Description: 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')
description: Resource Title: Data diameter modelling
 Size: 243750 bytes
 Format: .rds
 URL: https://www.envidat.ch/dataset/f8fe4971-0538-4d8e-b866-8d1cfd4b1584/resource/9cadbc57-7eab-4415-bf97-229d52cd412b/download/data_nfi4_diameter_modelling.rds
 Description: 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
description: Resource Title: Data species modelling
 Size: 450665 bytes
 Format: .rds
 URL: https://www.envidat.ch/dataset/f8fe4971-0538-4d8e-b866-8d1cfd4b1584/resource/03162eba-0bd2-400a-b0f7-75c7cf117269/download/data_nfi4_species_modelling.rds
 Description: 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')
description: Resource Title: Script diameter and species modelling
 Size: 16141 bytes
 Format: .r
 URL: https://www.envidat.ch/dataset/f8fe4971-0538-4d8e-b866-8d1cfd4b1584/resource/0e6e2a50-fb05-4236-b53f-a5bafaf7a069/download/script_diameter_and_species_modelling.r
 Description: 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'.
description: Resource Title: Functions diameter modelling
 Size: 20702 bytes
 Format: .r
 URL: https://www.envidat.ch/dataset/f8fe4971-0538-4d8e-b866-8d1cfd4b1584/resource/e3f02601-e820-4df9-bcc9-c21bea82dc38/download/functions_diameter_modelling.r
 Description: This R file contains the functions used to produce the generalised diameter distributions in Mey et al. 2021.