The best replacement for biome is ecosystem.

The best alternatives to biome are rated as following:
★★★★★  ecosystem
★★★  habitat
★★  biosphere
★  an ecosystem
★  ecozone
★  aquatic life zone
  climate
  ecosystem bigger
  aquatic
  ecoregion

Your alternative for biome is not listed? Suggest!
Speaking about biome, one probably shouldn't forget about soil rich in humus.

Other search terms related to biome and their ratings are:
★★★★★ soil rich in humus
★ cone-bearing evergreen trees
You have in mind a companion for biome and it is not yet here? Propose!



Google Trends

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biome
ecosystem
habitat