R4Mcubage (Version 0.5-5) is an R package designed to make easier and faster processing data from “tree rigourous cubature”. Tree rigorous cubature should be understood as the measuration of invividual tree stems and/or branches along their length, taking the stem/branch diameter outside bark and the stem/branch inside bark (optionally) at several fixed positions along the stem/branch length.

The package takes into account two types of crown shapes: excurrent and decurrent. For excurrent trees the basic unit for the measurement of the tree wood content (wood volume) is the stem, because branch wood content is considered negligible. For decurrent trees the branch is the basic unit for the measurement of the tree wood volume and it is assumed that one single stem might have multiples branches.

The packages has functions to perform the following operations:

• computation of the total volume of stems;
• interpolation of stem measures such as:
  • diameter at a given height/position of the stem, and
  • height/position at the stem for a given diameter.
• computation of merchantable volume as:
  • merchantable volume up to a given merchantable diameter of the stem,
  • merchantable volume up to a given merchantable height at the stem,
  • merchantable volume for wood use classes defined as combinations of a minimum log diameter and a log length.
• computation of ratio of the merchantable volume to the total volume of the stem.
• computation of form factor (empirical form factor) and form indices for the stem as a whole and for stem sections.

For decurrent trees data, some of the above computations can not be performed. The package also has some utility and plotting functions to help manage and analyse data from tree cubature.

The objective of R4Mcubage is to make easy the computation of tree stem measurements in order to obtain data tables needed for the Forest Biometrics modelling of the trees. Particularly, the package's goal is to turn raw field measurements into proper data tables of

• any diameter and/or height along the stem;
• stem volume for given diameters and/or heights along the stem; and
• volume and number of logs for given combinations of log diameter-length.

Which are the basic data needed for fitting models of:

• volume equations (total and merchantable);
• taper equations; and
• merchantable volume ratio index equations.

R4Mcubage is provided under GNU General Public License in a as-it-is basis, with NO support and NO service included.

Download, install and use at your own risk:

• Package under development as a .tar.gz file.
• Tutorial PDF.

E-mail in insilvaarbores.com.br.