About the Tundra Biome Edit
Tundra biomes are somewhat common and have very unique attributes. Each Tundra biome has a chance of being either mountainous or relatively flat. Both versions of this biome have grass but lack trees. The mountainous version comes with the addition of snow-capped peaks, while the flat version includes sand and water.
The grass is a variant of the 'Grass' block called 'Grass Tundra'.
It's a rather bad choice to start a colony here because of it's lack of wood, leaves, and saplings. A tundra colony will likely need to invest in some foresters early on to have a steady source of wood.