Which of the following statements about tropical rainforests are correct? 1. The soils of tropical rainforests are quite infertile. 2. The vegetation is evergreen, enabling photosynthesis to take place year around. 3. They have been described as 'deserts covered by trees'. 4. They are the most productive land-based ecosystem. Select the correct answer using the code given below. Correct Answer 1, 2, 3 and 4 The correct answer is 1, 2, 3 and 4. Key Points The tropical rain forest is a forest with tall trees in a region of year-round high temperatures. In the rainforest, most of the carbon and essential nutrients are locked up in the living vegetation, dead wood, and decaying leaves. As organic material decays, it is recycled so quickly that few nutrients ever reach the soil, leaving it nearly sterile. Hence statement 1 is correct. The tropical evergreen rainforest biome provides optimum environmental conditions for the growth and development of plants and animals because it is char­acterized by high rainfall and temperature throughout the year. Two-thirds of all plant species can be found in the tropical rainforest. Some of the plants in the rainforest have vital jobs such as exchanging gas and giving oxygen in exchange. Hence statement 2 is correct.​ The atmosphere in the tropical rainforest is hot and humid as the result of high temperatures and abundance of water and therefore called 'deserts covered by trees'. Hence statement 3 is correct. On land, the maximum primary production rate is found in tropical rainforests followed by tropical deciduous forests, temperate forests, savannah, temperate grasslands and desert scrub. Hence statement 4 is correct.