Flexible Tree Taper Curves Based on Semiparametric Mixed Models
c(person(given = "Edgar", family = "Kublin", role = "aut"),
person(given = "Johannes", family = "Breidenbach", role = c("ctb","cre"),
email = "job@nibio.no"))
Implementation of functions for fitting taper curves (a semiparametric linear mixed effects taper model) to diameter measurements along stems. Further functions are provided to estimate the uncertainty around the predicted curves, to calculate timber volume (also by sections) and marginal (e.g., upper) diameters. For cases where tree
heights are not measured, methods for estimating
additional variance in volume predictions resulting from uncertainties in
tree height models (tariffs) are provided.  The example data include the taper curve parameters for Norway spruce used in the 3rd German NFI fitted to 380 trees and a subset of section-wise diameter measurements of these trees. The functions implemented here are detailed in the following publication: Kublin, E., Breidenbach, J., Kaendler, G. (2013) A flexible stem taper and volume prediction method based on mixed-effects B-spline regression, Eur J For Res, 132:983-997.

c(person(given = "Edgar", family = "Kublin", role = "aut"),
person(given = "Johannes", family = "Breidenbach", role = c("ctb"),
email = "job@nibio.no"),
person(given = "Christian", family = "Vonderach", role = c("ctb","cre"),
email = "christian.vonderach@forst.bwl.de")
)
Implementation of functions for fitting taper curves (a semiparametric
linear mixed effects taper model) to diameter measurements along stems. Further
functions are provided to estimate the uncertainty around the predicted curves,
to calculate timber volume (also by sections) and marginal (e.g., upper) diameters.
For cases where tree heights are not measured, methods for estimating
additional variance in volume predictions resulting from uncertainties in
tree height models (tariffs) are provided.  The example data include the taper
curve parameters for Norway spruce used in the 3rd German NFI fitted to 380 trees
and a subset of section-wise diameter measurements of these trees. The functions
implemented here are detailed in Kublin, E., Breidenbach, J., Kaendler, G. (2013)
<doi:10.1007/s10342-013-0715-0>.
Edgar Kublin [aut],
Johannes Breidenbach [ctb],
Christian Vonderach [ctb, cre]