select_for_DAS_indicator.RdThis function does the first step(s) of the calculation of the DAS indicator, namely selecting the relevant forest reserves or plots based on the following criteria:
test for development stages: average diameter (DBH) between 200 and 700 mm
test for desired tree species: > 5 % of the proportion of the basal area should contain trees from the species groups beech, oak, ash/maple or pioneers (birch, willow, esp or rowan)
exclude homogeneous stands: basal area proportion of each tree species group < 98 %
select_for_DAS_indicator(data_to_select, grouping_vars)dataframe with at least all grouping_vars and the variables dbh_mm, species, basal_area_alive_m2_ha, and as records preferably only living trees (they are not filtered out here but they should not be in here to meet the requirements of the DAS indicator)
vector with variables that should be grouped on during the selection steps.
dataframe with the grouping vars in which records are removed that do not meet the above described criteria
if (FALSE) {
#change path before running
data_dendro <-
load_data_dendrometry("C:/MDB_BOSRES_selectieEls/FieldMapData_MDB_BOSRES_selectieEls.accdb")
select_for_DAS_indicator(data_dendro)
}