R/site_litter_isotopes.r

In Z10: Simple Ecological Statistics from the NEON Network

############################################################################################
#' @title Return Mean Delta Values of Stable Isotopes in Litterfall

#' @author Robert Lee \email{rhlee@@colorado.edu}\cr

#' @description This function calculates the mean delta values for
#' nitrogen-15 and carbon-13 isotopes over the period of record at a site.
#'
#' @param site Parameter of class character.
#' The NEON site data should be downloaded for.

#' @return A list of min, mean and max net solar radiation
#' values at the site, in watts per meter squared
#'
#' @examples
#' \dontrun{
#' cper=Z10::site.litter.isotopes(site = "SCBI")
#' }
#' @export

#' @seealso Currently none

# changelog and author contributions / copyrights
#   Robert Lee (2018-10-29)
#     original creation
#
##############################################################################################

site.litter.isotopes=function(site){

    dp.id="DP1.10101.001"

    litter.sites=dp.avail(dp.id)

    if(!(site %in% litter.sites$site)){stop(paste0("Litter stable isotope data are not available at ", site))}

    all=lapply(litter.sites$months[litter.sites$site==site],
           function(m)
               get.data(site = site,
                        dp.id = dp.id,
                        month = m
               )
    )
    flat=unlist(all, recursive = FALSE)

    iso.df=data.frame(do.call(rbind, .common.fields(flat)), row.names = NULL)

    out=list(
    d15N=mean(iso.df$d15N, na.rm = T),
    d13C=mean(iso.df$d13C, na.rm = T)
    )

    return(out)
}