Barb,
As Susan has pointed out, "The Pine Planters" is accentual dimeter. Other, more famous examples include Edna St. Vincent Millay's "
Moriturus" and Elizabeth Bishop's "
Sonnet (1979)".
Gregory is correct about the paucity of amphibrachs ("de DUM de") in poetry but modern song has provided two conspicuous examples: Gordon Lightfoot's "
Wreck of the Edmund Fitzgerald" (amphibrachs throughout) and Leonard Cohen's "
Famous Blue Raincoat" (which begins and ends in amphibrachs).
HTH,
Colin