Is there a Minecraft command for changing biomes?
Solution 1:
Short answer:
No, there isn't, and I don't think any mod can do this.
The biomes are generated by the world seed and the current generation rules. So to re-generate a chunk delete the exact save file, then go to a old version (like 1.3), open the world, generate the deleted chunks and then switch to 1.9
The other way is to make the biome look like another biome by replacing the dirt by sand or oak wood to some other wood.
Example of "changing" a forest to a desert:
/fill ~-25 ~-5 ~-25 ~+25 ~+5 ~+25 minecraft:sand 0 replace minecraft:dirt
/fill ~-25 ~-5 ~-25 ~+25 ~+5 ~+25 minecraft:sand 0 replace minecraft:grass
/fill ~-25 ~-5 ~-25 ~+25 ~+5 ~+25 minecraft:air 0 replace minecraft:leaves
/fill ~-25 ~-5 ~-25 ~+25 ~+5 ~+25 minecraft:cactus 0 replace minecraft:wood
Example of "changing" a desert biome to plains:
/fill ~-25 ~-5 ~-25 ~+25 ~+5 ~+25 minecraft:grass 0 replace minecraft:sand
/fill ~-25 ~-5 ~-25 ~+25 ~+5 ~+25 minecraft:stone 0 replace minecraft:sandstone
/fill ~-25 ~-5 ~-25 ~+25 ~+5 ~+25 minecraft:air 0 replace minecraft:cactus
/fill ~-25 ~-5 ~-25 ~+25 ~+5 ~+25 minecraft:air 0 replace minecraft:dead_bush
These commands will, if executed, "replace" the surrounding biome with another. You can fiddle with the numbers to get a bigger part filled, and you can set up command blocks getting activated every ~10 seconds (~40 Repeaters) with these commands:
/execute @a ~ ~ ~ fill <yourFillCommand>
Solution 2:
If you are on a server, you can use WorldEdit (the plugin).
SPC, short for Single Player Commands, is a mod that allows you to use WorldEdit on singleplayer and LAN.
When you do //biome with WorldEdit, all other articles will be explained.
Solution 3:
You can change the biome in super-flat worlds in single player but I don't think you can change biomes in Minecraft.
Changing biome in super-flat world: -Create a new world -More world options -World type super-flat -Customize -Presets
There should be a long command at the top. It should like something like this: minecraft:bedrock,2*minecraft:dirt,minecraft:grass_block;minecraft:plains
You can type in another biome in place of the plains:
for example:
minecraft:bedrock,2*minecraft:dirt,minecraft:grass_block;minecraft:jungle
This will make your super-flat world have a jungle biome. Make sure you spell the biome type correctly and if it consists of multiple words (mushroom fields) that it has an underscore where the space would be(mushroom_fields)
Solution 4:
There is a way but it is a bit convoluted. You have to go into the worlds chunk files. I recommend using NBTExplorer.
Inside of the region folder in the save file there will be a bunch of .mca files. The name of each file represents each region and a region is 32x32 chunks. Find the file name that includes the chunk coordinate for the chunk you are looking for then open it in NBTExplorer.
When you find the chunk you would like to edit, press the plus next to it. Then press the plus next to Level. This will drop down a lot of info but you are looking for Biomes. This is a set of 1024 integers that represent each column's biome. Each number represents a different biome.
I do not know which numbers represent each biome so you will have to find that out on your own. Once you replace all the numbers with the ones that you want, then the biome will be changed.
Sorry that this is so hard. I don't know any better way of doing this right now. Hopefully this is helpful. If you need help just reach out to me and I'll help how I can.
This is also a bit late now I realize. Oh well.