howto exclude a subtree in pdf generation?

Hi,

I wonder whether there is an easy way to exclude a part of
the
documentation that is still generated for html-output for
the wholesite.pdf?

In my particular case I put a doxygen-generated html-tree to
forrest
which itself generates a lot of output and it is much easier
to take the
latex-output from doxygen to generate a pdf than using the
wholesite.pdf
in this case.
And in this case as I generate a lot of dependency graph
forrest will
just fail to create the wholesite.pdf file since it
encouters the bug in
fo(?) that prevents to add pictures to tall to pdf.
(No flow in page-sequence)

Kind regards

Thomas