The Redwood Biome Has redwood trees in it. The new horsetails spawn in it.
chickens can spawn in it.
with redwood wood you can make any tool but No crafting table or sticks.
The mangrove biome has lots of water in it and no new other blocks apart from Mangrove
Nothing can be made with mangrove wood.
Only 2 mobs can spawn in this biome, cod and salmon
Mangroves will always spawn next to oceans