Here's a breakdown:
Classification:
* Climate: The most important factor for biome classification is climate, specifically temperature and precipitation. Biomes with similar climates will share similar plant and animal life.
* Vegetation: The dominant plant life of a biome is a key characteristic used for classification. For example, forests have dense tree cover, grasslands have grasses, and deserts have sparse vegetation.
* Animal Life: The animal life adapted to a particular biome is another important factor.
* Other factors: Factors like soil type, elevation, and latitude also play a role.
Counting:
While there isn't an official "count" of biomes, scientists typically recognize 8-14 major terrestrial biomes. Some common biomes include:
* Forests: Tropical rainforests, temperate deciduous forests, boreal forests (taiga)
* Grasslands: Savannas, temperate grasslands, steppes
* Deserts: Hot deserts, cold deserts
* Tundra: Arctic tundra, alpine tundra
* Aquatic biomes: Oceans, lakes, rivers, wetlands
It's important to note that:
* Biomes are not discrete units: They often blend into each other, forming ecotones (transition zones).
* Biomes are dynamic: They can change over time due to factors like climate change, human activities, and natural disasters.
Overall: Biomes are classified based on their unique combination of climate, vegetation, and animal life, and scientists typically recognize a certain number of major biomes.
