Divergent herb communities in drier and chronically disturbed areas of the Brazilian Caatinga

•Caatinga dry forests are becoming increasingly drier and chronically disturbed.•Herb communities negatively respond to rainfall reduction and increase disturbance.•Responses may be mediated by the local density of woody plants.•Multiple successional pathways should emerge with the new environmental conditions.•Management and conservation actions are urgent to protect Caatinga herb diversity.