what are the worlds rainforests
By Amanda Briney, Contributing Writer. A rainforest is a forest differentiated by high levels of precipitation-normally a minimum of at least 68-78 inches (172-198 cm) annually. Rainforests tend to have fairly mild and/or warm climates and feature the highest levels of biodiversity in the world.he largest in tact tropical rainforest in the world is in the Amazon River Basin. Tropical rainforests form in these locations because they are within the ITCZ, which provides the warm temperatures common in the forests. Due to the temperatures and plant growth, transpiration rates are high.