Biodiversity refers to the numbers and kinds of living things that exist in an area. About 1.5 million species have been identified. Scientists believe that there are manga millions more species that have get to be discovered. The largest group of known species is insects. Earth has three times more insects than plants. Some areas are more diverse than others. An area is more diverse if it has a great variety of niches. Which has more niche diversity, a desert or a rain forest? You are correct if you said rain forest. Deserts are usually the same from area to area. A rain forest has lagers upon layers of places to hide, hunt, eat, reproduce, and build nests. Earth's most diverse ecosystems are along the actuator. One of the reasons for this is that the climate is similar there all year long. Species have plenty of food, rainfall, and shelter. Plants are always growing and never shed their leaves. Organisms there don't have to survive liars} winter conditions.