Answer:
Eco-region
Step-by-step explanation:
An eco-region, also known as ecozone, is an ecological area defined by environmental conditions and natural features. An eco-region is defined by conditions such as soil type, temperature etc. Eco-regions have features like soil, that defines its boundaries. Eco-regions can be classified into biomes.
Hence, according to this question, an area defined by environmental conditions and natural features is known as ECO-REGION