survey_overview: Generate an Overview of the Surveys of an fe_stand Object

In ForestElementsR: Data Structures and Functions for Working with Forest Data

Generate an Overview of the Surveys of an fe_stand Object

Description

The tree data frame of an fe_stand object is evaluated in order to get survey and species specific meta information about these data.

Usage

survey_overview(x, tree_filter = TRUE)

Arguments

x	An object of class fe_stand
tree_filter	A data-masking expression that applies to the data.frame x$trees. It must return a logical value, and is defined in terms of the variables in x$trees. In this function, it is used internally in order to define the cohort of trees which is to be evaluated by this function (within a call to dplyr::filter()). For this function, tree_filter should almost never be something else than TRUE (default)

Details

This function provides meta information that is useful for evaluations that can be complex on the detail level, e.g. increment calculations from subsequent surveys. In such contexts, the column n_species_occurence of the output data frame can be of special interest. If a species is present for a number of consecutive surveys, all these surveys get the same integer number in this column. If the same species vanishes, but occurs again later, the next block of surveys gets the subsequent number, and so on. So, all consecutive blocks of a species' occurrence are numbered as 1, 2, 3, etc. At surveys where the species is not present n_species_occurrence has the value 1.

Value

A data frame (tibble) that gives an overview of the surveys represented in the input object x. It is basically an evaluation of the data frame x$trees. It provides information about how many trees were present in each survey, how many dbh and heights were measured, and if the dbh and height measurements cover all trees, For dbh this must be always true, because this is a requirement for a valid fe_stand object. In addition, we are informed whether a species that has been documented in the object is represented in a specific survey or not. As a basis for advanced evaluations, species occurences are numbered in the columen n_species_occurrence (see Details). In case an object of class fe_ccircle_spatial_notrees (which is a special child of fe_stand) is provided as input x, the function returns an empty data frame.

Examples

  # Example data: Mixed mountain forest plot with several surveys
  mm_forest_1_fe_stand_spatial |> survey_overview()

ForestElementsR documentation built on April 3, 2025, 7:47 p.m.