I swapped the Green and Brown in Blender node 3, used a drak grey instead of black in blender nodes 1 & 2 and dropped the specularity to .01 and rather like Shuy's material. I suggest playing with the colors in the blender nodes to see what sort of barks you can come up with. 

 

As for the shininess of bark, that would depend on whether or not it was wet. Moisture would of course add shininess to bark.