I don't know how much you'd like to consider or look into, but these are my thoughts. I present them to thee to take as thou seest fit *kneels with hands stretched forth* They are but ideas, my liege.
I'm curious to know about the spotlights and the backdrop... Are the spotlights meant to be light filtering through the canopy? And relating both to the spotlights and to the backdrop; what time of day is it and what season?
To me (in my uneducated eyes) the filtering light gives more of an afternoon almost sunset effect or maybe a summery warmth (from the yellow). It's also a little odd to look at because it doesn't illuminate so much as it does change the color of whatever it hits. This might be just me, but when I think of light filtering in a forest, it adds more depth the whatever it touches. Bright leaves become brighter and warmer while dark shadows get deeper and cooler.
The backdrop is kind of leaving an impression of an open field, though the trees suggest that it's meant to be continuing forest thickets. Also, the strict use of green isn't really reading as any particular time of day or season to me. In any case, it might help if you use cooler colors for the shading Add a little blue or remove some yellow. I just learned about that bit myself, so I could be all wrong, but I think it might help.
I did this really quick, so it's not great, but this should help show what I'm talking about with shading with cooler colors. Compare the tree trunks to the original. (I just realized that I didn't color the trunks inside the spotlights... so... ignore those sections?)