Biomes

Biomes are the environment of a given planet, determining nearly everything about its usability from food production to industry. They range from idyllic Gaia-class planets to hellish Toxic or Volcanic death worlds.

Nearly all Biomes can be upgraded in one way or another, improving their habitability.

Legend

 * The cells percentage is simply the maximum amount of cells available for the relevant purpose on the given biome type. A planet's total number of cells is divided in two, half for agriculture and half for industry. The percentage shows how much of these cells are actually usable. For example, a large world has 20 cells, so it has 10 farmable cells and 10 productive cells. A terran world has 80% farmable and 70% productive, meaning 8 farmable cells and 7 productive cells. (Science cells are not limited.)
 * Terraforming and transformation projects move the planet up one class. Pollution, if not cleaned up, will degenerate a planetary biome one class down once it reaches 100% (eg. a Terran B-class planet becomes a Swamp or Arid C-class planet).
 * With the Unofficial Code Patch, pollution absorption also depends on planet size. It is 60% of given value for tiny planets, 80% for small, 100% for medium, 120% for large, and 140% for huge.