1. Climate: This is the most important factor, as it determines the types of plants and animals that can survive in a particular area. Climate includes average temperature, precipitation, and seasonal variations. For example, tropical rainforests have consistently high temperatures and rainfall, while deserts have low rainfall and extreme temperature fluctuations.
2. Plant Life: The dominant plant life forms within a biome are a direct result of the climate. For example, the presence of tall trees indicates an area with sufficient rainfall and sunlight. The types of plants present also influence the animal life that can thrive there.
By combining these two factors, scientists can categorize the Earth's diverse environments into distinct biomes, such as grasslands, forests, deserts, and tundra.