I am a high school student and I am a little confused. In my textbook, while discussing the longitudinal pattern of biodiversity they say one of the reasons is that "tropical areas have more species diversity because there is more intense solar radiation which will increase vegetation and productivity which might indirectly affect the diversity of other species". There were other reasons as well, but I don't really understand this line. My teacher says, it is simple where there are more food resources species will love to live there but I think this is incorrect, species are not moved from temperate areas to tropical areas, they are always present abundantly in tropical areas. So how can more food relate to species diversity? Please explain in easy language without using many technical terms.