pg_dumping schemes (not schema)

Although I group my data topically in databases, most
of the data is integrated on the client side
(MSAccess). That is, tables from different databases
are often joined together during analysis.

I'm thinking of simplifying analysis and
administration by consolidating the databases and
separating the tables into topics using schemes.
Unfortunately, the resulting data dumps would be huge.
The alternative, pg_dumping individual tables, would
result in a very high number of backup files to
manage.

Is there a way to pg_dump a scheme at a time?

Thanks,

Andrew Gould