Browns and highlights
When you remove all of the green foliage, the ground is essentially shades of brown (to state the obvious). If I were to redo this painting, perhaps I would have added more brown/orange color in the underpainting. All is not lost, however, as reddish-browns were added to break up the greens. I softened the browns by cross-hatching a dark green hard Nupastel.
Here's the updated version of the painting (almost time to pick a name for it).