Board Game Arena

I've discovered Living Forest very recently. This game seems to have 2 versions, because on my last game there was something I had never saw before: it looks like a kind of chinese sign. Im not really sure what's the purpose of it or what it changes in the game. I also noticed new cards with this sign on...

Can someone explain to me all what I have to know about this, please!

Read the rules of the Kodama expansion and all will be clear