Dauntless Dourbark's power and toughness are each equal to the number of Forests you control plus the number of Treefolk you control.
Dauntless Dourbark has trample as long as you control another Treefolk.
A permanent that’s both a Forest and a Treefolk will be counted twice when determining Dauntless Dourbark’s power and toughness.
Dauntless Dourbark counts itself when determining its power and toughness.