What factor primarily influences the distribution of terrestrial biomes?

The distribution of terrestrial biomes is primarily influenced by water availability and temperature because these two factors determine the climate conditions that support different types of vegetation and animal life.

Water availability is crucial because it influences the types of plants that can grow in an area. For example, deserts have very low water availability, which limits the types of organisms that can survive there, leading to biome characteristics distinct from those found in tropical rainforests, where high moisture levels support diverse and abundant plant life.

Temperature plays a significant role as well, affecting the metabolic rates of organisms, the rates of evaporation, and ultimately the types of ecosystems that can exist in a specific region. In colder regions, certain species may not survive, whereas warmer temperatures can support a wider range of biodiversity.

While latitude and altitude variations do have an impact on climate and therefore indirectly affect biomes, water availability and temperature are the more direct factors that define the primary biotic and abiotic characteristics of each biome. Soil type and pH level influence local ecosystem dynamics but are considered secondary influences compared to the overarching effects of water and temperature. Similarly, while species interactions like predation can shape community structure, they do not determine the overarching biome types which are primarily dictated by climatic factors.