A living line of green I stand, Between two plots of careful land. I block the view, but not the breeze, Shaped by hands and buzzing bees. What am I?

It begins a race, Or stops a game A bird's call for a mate, Or a human's, on the sidewalk

Q Tongue Iceberg Finger Hint: I complement most and am kind of a synonym of the last.

Something that adorns your chest up. Rubies, diamonds, and gold, oh my!

Hold me, Spin me, Put me down. Label me, cover me, Your message, bound.