The study looked at how different types of vegetation in the mid-mountain area of Hainan Island in South China changed over time. They found that as the vegetation evolved from grassland to primary forest, the number of different species increased. The researchers used different indexes to measure species diversity and found that certain indexes were good at showing how diverse the species were and how evenly they were distributed. They also found that the types of species changed as the vegetation evolved, with the most turnover happening between the shrub and secondary forest stages.