Great shot! But don't you mean "Trees and moon"? You can't leave out that small one in the distance. It looks like the larger tree is protecting it as if it were a child.
You could do a selection on the sky and then invert it to adjust just the ground. Interesting thing is, this seemed to have more visual impact in the thumbnail. I think it was because with the lack of detail in the thumb, the lines stood out more. but, that probably why you want to adjust the contrast, anyway.
The dirt needs more contrast, but posterization is evident in the sky
and increasing contrast will not help, toning might cover it up some. Your running out of data.
Make your b&w conversions in 16 bit even if you are starting with an 8 bit jpeg.
It's a matter of taste, I would go for a little bit more but that just me. A way to increase constrast especialy in b&w is to sharpen the image with small amount and big radius. I'm in a laptop now and I use gimp under linux, usualy use an amount of .50 and radius of 50 in a second layer and then adjust opacity accordingly (ditto about the equivalent in ps).
btw. the small moon, the big tree and the small tree create a quite an antithesis in this picture. great framing.