Biome



According to Wikipedia, biomes are climatically and geographically defined as similar climatic conditions on the Earth, such as communities of plants, animals, and soil organisms, and are often referred to as ecosystems.

In Minecraft, from the Halloween Update onwards, this means that different areas with varying heights, temperatures, humidity ratings and foliage colors are created.

Before the Halloween Update, when a map was generated it had either a Snowy or Grassy theme. But after the update, a single world includes all themes in a logical fashion determined from the biomes graph.

A demonstration can be viewed here.

Biome Types
Biome types may be easily distinguished by the differentiating grass and leaf colors in conjunction with the kind of blocks present, like cacti in deserts and pine trees in pine forests. They are randomly created during the generation of the world and are affected by the starting seed.

There are nine biomes in Minecraft 1.0 and 1.1.

Desert


A very flat biome consisting mostly of sand, dead shrubs and cacti. No rain occurs in this biome. Sugar Cane can be found sometimes next to pools of water. NPC Villages spawn mostly in this biome or near it.

Forest


A biome with many trees and a fair amount of tall grass. Birch trees can be found in this biome.

Mountain


A highly mountainous biome with dull grey-blue grass and few trees, added in the 1.8 Adventure Update. Prior to this update, mountains were found in all types of biomes, but now are very rare outside this type of land. More underground cave systems are present here than any other biome.

Mountain Edge


Acts as a fringe between mountains and most other biomes.

Ocean


A very large, flat open biome made entirely of water, with underwater reliefs such as small mountains and plains and usually includes sand and clay at its bottom. Ocean biomes can go down to 30 blocks deep and the occasional island may exist, as a small version of other biome types. Entrances to underground ravines can be also found at the bottom of the ocean, as well as Abandoned Mine Shafts (whose upper parts are mostly flooded due to the proximity of the ocean). Oceans can be larger than ten thousand blocks wide and long.

Frozen Ocean


Found near snow biomes, frozen oceans contain ice.

Beach


Generated on ocean shores, and is composed of mostly sand.

Mushroom Island


This biome consists of flat landscapes and high hills, has Mycelium instead of grass as its common surface block, and tends to appear as islands far from the spawn of a map and any significant landmass. It is the only biome where Huge Mushrooms can spawn and grow naturally, where mushrooms grow in full sunlight, and where Mooshrooms spawn.

Contrary to popular belief, trees can be grown in this biome, but not next to Mycelium which will take over the dirt square from the sapling and un-plant the sapling. A player can create a Mycelium-free zone with cobblestone and grow a tree in the middle of it on freshly placed dirt. A player is also able to place saplings on mycelium and use bonemeal on the sapling to grow it. Otherwise, it is advised to collect wood (and saplings) before settling here.

No mobs other than Mooshrooms (including hostile mobs at night) spawn in this biome. This includes caves, abandoned mines, etc... below Mushroom Biomes, meaning exploring underground is relatively safe. Dungeons with spawners will still spawn mobs, however, and caution should still be taken when exploring (as sometimes "fingers" of other biomes project into mushroom biomes).

As of 1.1.0 player made structures in this biome are not exempt from the "no mob spawn" rule: All terrain within the biome will not spawn hostile or passive mobs, even if created by the player.

The actual Mushroom Island biome represents the highly mountainous inland area of the island.

Mushroom Island Shore
This biome represents the flat shore area of the Mushroom Island.

Plains


A relatively flat biome with rolling hills and a large amount of tall grass (more than in any other type of land). The occasional tree does exist, although very rarely. Gullies are also quite common in this biome. Forests can be found within large plains.

Swampland


A flat biome with swamp-like trees with vines and shallow pools of clay, sand and dirt. The water, grass, leaves, vines and trees are much darker. The water can have floating lily pads. Mushrooms are also moderately common in swamps. There is a greenish color in the water. Trees can sometimes spawn in the water in this biome. From 1.8 to 1.0 water was very dark, but as of 1.1 the transition is smoother, making it a little harder to tell whether it is normal water or swamp water.

Taiga


A biome with many pine/spruce trees and dull grey-blue grass. Wolves are also found on this biome more commonly than others. As of 1.8, the player is most likely to spawn in one of these biomes. Snow and Ice occur in this biome after Minecraft 1.1.

Tundra


A relatively flat biome covered in snow. Lakes and rivers are mostly frozen over and trees (only regular types are spawned) are scarce. Sugar canes do spawn in this biome, but are destroyed and dropped when the chunks load because of the ice that spreads over open water sources. Tundras are often significantly larger than other biomes in the area.

Jungle


A biome added in Snapshot 12w03a. It consists of tall trees that are 2 blocks wide along with many small ones. The landscape is slightly hilly, with some small lakes of water. This biome will only generate in worlds created using or after the version 12w03a. It is the only source of ferns since their removal in Beta. Leaf "bushes" can be found near pools of water. Most trees are larger than those in other biomes. This is the only biome consisting of Jungle Wood and Jungle Leaves (Not official block names). There are large amounts of vines that can be climbed if correctly oriented, allowing the player to reach higher areas of the jungle easily. As of Snapshot 12w04a, Ocelots were added and spawn in jungles.

River


A biome that consists of water blocks that form in a curvy pattern like rivers. Rivers cut through terrain and attempt to join up with ocean on the other side, but will sometimes loop around to the same area of ocean. They have no current. Rivers have also been known to be a reliable source of Clay. Although different than other biomes, they are referred as biomes in the code.

Frozen River


Found in snow biomes, frozen rivers contain ice and snow.

Hills


Hills are generated within certain biomes: Forest, Taiga, Desert, Jungle and Tundra. Each separate area of hill biome spawns one hill in the shape of the area. Tundra biomes spawn mountains instead of hills.

Basin


Not much of a biome as it is a terrain feature. It is made mostly of Stone, but also of other blocks, such as spots of dirt. In Geology it would have come from increased erosion because they are tectonically stable areas. There is a large misconception in the community that these are errors, however they are an intended feature, and referred to as shields in the source code.

History
Biomes were added in Alpha 1.2.0, also known as the Halloween Update. In Beta 1.8, biomes got an overhaul, removing some biomes and others replaced with nine fractal-based biomes - some old, some new.

Difficulty
It can be difficult to play and gather sufficient resources if one starts in the middle of a biome with no trees, such as deserts, tundras, and especially oceans.

There have been multiple reports of players spawning on tiny islands in the middle of a vast ocean with no trees for several Minecraft days in any direction. It appears that these desert islands generate in the Ocean biome, where animals cannot spawn (on the water); sometimes the island spawns with no trees so players have to delete the world and start again, swim great distances to a landmass, or search for nearby underwater openings into abandoned mineshafts to acquire wood. Of course, this is no problem if the player uses Creative Mode.