Object mtree
defines a tree with species as tips. If argument height
is NULL
, then the root of the tree will be placed at the most recent common ancestor of all species occurring in the set of plots (given in object comm
). An alternative position for the root can be given by specifying the height of the tree (argument height
). In that case, height
must be higher than the distance between tips and the most recent common ancestor of all species.
The tolerance threshold tol
is particularly important if your tree is not exactly ultrametric due to approximation problems. In that case, the distance from tip to root varies according to the tip considered, although it should not (variations are due to approximation problems). A difference smaller than tol
in the distance to root for two species will thus be considered as null.