Abstract
In this paper, we show that the group of all tame automorphisms of the free metabelian Lie algebra [Formula: see text] of rank [Formula: see text] over a field is an amalgamated free product of its subgroups. Moreover, we prove that the group of all almost tame automorphisms — that is, the subgroup generated by all Chein automorphisms (or one row transformations) of [Formula: see text] — also admits an amalgamated free product structure. By using these results, we provide simpler proofs of the wildness of certain automorphisms.