Democrats on the House Foreign Affairs Committee yesterday took away the chairmanship of the Latin American subcommittee from Rep. Gus Yatron (D-Pa.) and gave it to Michael D. Barnes (D-Md.), saying there needs to be a more active chairman dealing with such a sensitive area.

When committee Democrats met in caucus to organize the majority side of the committee, Yatron bid to retain his chairmanship but was rejected, 10 to 9. The caucus then turned down an effort by Rep. Dan Mica (D-Fla.) by an identical vote before electing the second-term Barnes from Montgomery County, 14 to 5. v

There had been indications for several weeks of trouble for Yatron, a 12-year House member seldom heard from in House debate. Some junior members felt he might not give Congress proper guidance on Latin American issues or provide an adequate counterweight to conservative Sen. Jesse Helms (R-N.C.) who chairs a similar subcommittee in the Senate.

Barnes came to public attention last summer when he led a last-minute fight for an "open" national Democratic convention to find a presidential alternative to Jimmy Carter.

Rep. Howard Wolpe (D-Mich.), another second-term member, was elected chairman of the Africa subcommittee which Rep. Stephen J. Solarz (D-N.Y.) gave up to head an Asian subcommittee previously chaired by the defeated Lester Wolff (D-N.Y.). Wolpe is an African specialist, having lived two years in Nigeria and having taught a college course on African affairs.