Thousands of small farmers were forced from their lands and homes by paramilitaries in Colombia's Santa Maria mountains, writes Paula Álvarez. But now as a welcome peace allows their return from involuntary exile, they find a new enemy that has come to stay - huge plantations of oil palm that have obliterated the mixed, patchwork landscape of small fields, villages, and swathes of forest on steep-sided hills that they used to inhabit.
