Geography – Tropical environments | e-Consult

Tropical rainforests are predominantly found in the equatorial regions of South America, Africa, and Asia. While human activity has significantly impacted their extent, physical factors remain crucial in determining their distribution. Temperature is a primary driver, with consistently high temperatures (averaging 20-29°C) and minimal seasonal variation essential for the rapid growth and decomposition characteristic of rainforests. High annual rainfall (typically exceeding 2000mm) is equally vital, supporting the dense vegetation and high biodiversity. High levels of solar radiation contribute to evapotranspiration, further fueling rainfall. Nutrient-poor soils, often derived from heavily weathered bedrock, are a significant constraint on plant growth, necessitating rapid nutrient cycling through decomposition. Relief, while not a primary driver, can influence rainfall patterns (e.g., orographic rainfall on mountain slopes) and soil drainage, indirectly affecting rainforest distribution.

However, it's important to acknowledge the role of other factors. Latitude is a fundamental determinant, as rainforests are concentrated within the equatorial zone. Altitude can also play a role, with montane rainforests found on high-elevation slopes. Distance from the coast can influence humidity levels.

While physical factors provide the fundamental requirements, the distribution of rainforests is not solely determined by them. Historical factors, such as continental drift and the breakup of Gondwana, have played a long-term role. Human activities like deforestation are increasingly overriding these natural constraints. Therefore, while physical factors are essential, they do not fully explain the distribution of tropical rainforests.