The light green regions are Eriador, the dark green and brown regions are the Northlands and Northern Taigia, (Different then snowy taigia and snowy northlands) and above Pinnith Galen is the Land of Western Gondor, a Renewed exclusive biome. (It doesnt have a page however.)

Not eriador, but ok so the lands above the regular taiga are snowy taigas and snowy tundras?

And below forochel is the casual tundra?

Also wth is below that wierd biome below ered wethrin what is the biome above erebor and why is the erebor biome green now and so thick?

The Erebor biome has not been added in Renewed yet. (Hope it does get added soon though.)

...

I love how you haven't answered a question straightfoward and they are probably deducing