Board Thread:LotR Mod Technical Support/@comment-24.18.203.226-20190619181226/@comment-25612015-20190620043516

From a storage point of view, you probably can’t because the LOTR biomes are defined in the mod’s map and the LOTR biomes variants are defined in region files but with a different NBT key than vanilla Minecraft biomes (which are still defined too). Check this page for additional info, and this tool for listing LOTR biomes and variants (and perhaps manipulate them, one day).