Compute weighted AGB by strata

Assigns strata weights to circular plots and computes the weighted mean and standard deviation of above-ground biomass (AGB) and tree standard deviation based on strata sizes.

Usage

StrataAGB(
  plots,
  strata_weights = c(A = 0.22, B = 0.22, C = 0.68),
  verbose = TRUE
)

Arguments

plots

A data frame containing plot data with columns AGB_T_HA (numeric, AGB in tons per hectare), sdTree (numeric, standard deviation of tree measurements), and optionally stratum (character or factor, strata classification). If stratum is missing, it will be assigned based on the default weights.

strata_weights

A named numeric vector specifying weights for each stratum. Defaults to c("A" = 0.22, "B" = 0.22, "C" = 0.68), representing proportional areas.

verbose

Logical; if TRUE, prints the weighted mean AGB and standard deviation. Defaults to TRUE.

Value

A list containing:

wm

Weighted mean of AGB (tons per hectare).

wsd

Weighted mean of tree standard deviation.

weighted_plots

The input data frame with weights assigned in a wt column.

Examples

  # Example 1: Basic usage with synthetic data
  strata_plots <- data.frame(
    AGB_T_HA = c(100, 150, 200),
    sdTree = c(10, 15, 20),
    stratum = c("A", "B", "C")
  )
  result <- StrataAGB(strata_plots)
#> Plot AGB is 170.54 with SD 17.05 
  print(result$wm)  # Weighted mean AGB
#> [1] 170.5357
  print(result$wsd) # Weighted standard deviation
#> [1] 17.05357

  # Example 2: Custom weights and no printing
  custom_weights <- c("Low" = 0.3, "High" = 0.7)
  plots <- data.frame(
    AGB_T_HA = c(120, 180),
    sdTree = c(12, 18),
    stratum = c("Low", "High")
  )
  result <- StrataAGB(plots, strata_weights = custom_weights, verbose = FALSE)
  print(result$weighted_plots)
#>   AGB_T_HA sdTree stratum  wt
#> 1      120     12     Low 0.3
#> 2      180     18    High 0.7