This is how I play it, capo on 4 Picking in chorus and intro Am Am C G
e ---------------------------------------------------------|
B ----1---1------1----1--------1---1----------0----0-------|
G ------2-------2---2------------0-----------0---0---------|
D ---------------------------------------------------------|
A --0----------0-------------3-----------------------------|
E ------------------------------------------3--------------|
Am |C G| (5x) Am C G trees, oh trees Am C G do you remember me? (2x) G G Am C from before (4x) G G Am C G and birds, oh birds Am C G can you recall my songs? (2x) G G Am C from before (4x) G G Am C G fire, oh fire Am C G i can still feel your warmth (2x) G G Am C from before (4x) G G Am* like before
Source: http://www.guitartabs.cc/tabs/i/i_am_oak/on_trees_and_birds_and_fire_crd.html