Step 1: Understanding the Concept
A biome is a very large regional unit marked by its climate (temperature and rainfall) and its typical dominant vegetation and animals.
Step 2: Apply
Arctic tundra, coniferous (taiga) forest and grassland are each such major terrestrial units.
Step 3: Compare the options
A population is one species in an area, a community is all interacting populations of an area and a niche is the functional role of a species.
Final Answer:
These are examples of biomes.
\[ \boxed{\text{(C) }\text{Biomes}} \]