The Ecological niche is the total amount of life an ecosystem of a planet can support. The amount of "free spaces" in the niche depends largely on the Terrascore of the planet. When the Ecological niche is full, any plants and animals you try to add will instantly become extinct. On Tier One (T1) planets, plants must be placed before herbivores, because the herbivores would starve without plants. Carnivores must be placed after two herbivores are placed, because it would starve if there weren't any herbivore species to hunt. If a carnivore is introduced to a planet with only one herbivore, the herbivore will be overhunted and become extinct. Once that happens, the carnivore starves to death and become extinct. On higher Terrascore 2 planets, another set of plants and animals are allowed, and another set on Terrascore 3 planets. By using the Staff of Life all niches get filled automatically.
- Although omnivores can supposedly be both herbivores and carnivores, they only count as a carnivore. This may be because they have a tendency to hunt.