Cycle trip Yangshuo

Love the photograph(s) and would like to know more about your impressions of the scenery and geology. For as long as I can remember I've seen these mysterious looking hillocks on travelogues about China and been impressed by how spooky and alien they make the countryside seem. Do the locals use these hills? They always look covered in plant life but is it a monoculture? Do they support a complex or simple ecosystem? I suppose I should look up Wikipedia but if you happen to be interested yourself, your impressions would be much appreciated.