  The original motivation for study for hook length polynomials was to find a
combinatorial proof for a hook length formula for binary trees given by
Postnikov, as well as a proof for a hook length polynomial formula conjectured
by Lascoux. In this paper, we define the hook length polynomial for plane
forests of a given degree sequence type and show it can be factored into a
product of linear forms. Some other enumerative results on forests are also
given.
