Ecologists use similarities between terrestrial ecosystems to classify them into larger categories called ...

A. Littoral Zones

B. Climatographs

C. Biomes

D. Limnetic Zones

The answer is Biomes.

Biomes are very large ecological areas on the earth’s surface, with fauna and flora (animals and plants) adapting to their environment. Biomes are often defined by abiotic factors such as climate, relief, geology, soils and vegetation. A biome is NOT an ecosystem, although in a way it can look like a massive ecosystem. If you take a closer look, you will notice that plants or animals in any of the biomes have special adaptations that make it possible for them to exist in that area. You may find many units of ecosystems within one biome.