The birch forest is a lush temperate biome that is a variant of the forest biome. It comprises mostly birch trees, but there can be some oak trees that sometimes spawn as well. If the biome is a hilly version, the birch trees can be extra tall.
Birch forests feature a vast amount of birch trees across the landscape. They generate densely, but not densely enough to cast sufficient shadows to allow hostile mobs to spawn during the daytime. Flowers such as rose bushes, lily of the valleys, lilacs, and peonies generate in these biomes quite commonly, as well as the usual dandelions and poppies. The grass and foliage color is turquoise, making them hard to distinguish from rivers, which often run across this biome, and meadows, which can form clearings when this biome generates in very hilly areas.
Birch forests are a variant biome of forests, they can be found quite easily as they generate quite commonly. They are densely populated with birch trees and most passive and hostile mobs can be found here. They don't have any unique features.
A. No, birch forests are one of the most common biomes.
A. When a birch forest is generated in a hilly landscape, birch trees grow taller than usual.
A. The birch forest biome was added to Minecraft in Beta v1.2.