1) select - color range - (pick dark area) fuzzyness 100
2) select - modify - contract - 3pixels (varies, this is the size for this small image)
3) New layer - levels - adjust as wanted to change forground info (input 0,1.22,90 ... utput 11,255)
4) (with adjustment layer selected) filter, blur, gausian blur 3 pixels (varies, but usualy the same number as in step 2) - this smooths the adjustment
using this same technique, and playing with color balance, I also 'tweaked' the sky.
changed picture below