Really cool faction, with a nice flow of spreading spores and using them to build and recruit! I like that you can spread the spores anywhere but it's more costly if you don't rule the clearing. And the Death Burst seems like a cool way to mitigate your damage if you know you're going to be losing you warriors anyway.
I think you can probably simplify some of the wording relating to the spore chamber. Since there are no bonuses or points related to placing them you can probably remove the directions on how to place them in the track. And since you always add 3 in Birdsong and discard any excess above 6 you might be able to get rid of the 2nd phase in Evening as well. Unless there's a way you can use spores outside of your turn that I missed. If you had 6 and discard down to 3 at the end of your turn, you'll be back up to 6 at the start of your next turn anyway.