The researchers studied how different types of plants change with altitude on Mt. Taibai in China. They looked at 83 plots on the mountain and found that temperature and humidity were the main factors affecting plant diversity. As altitude increased, the number of plant species decreased, especially in the tree and shrub layers. Plants on the southern slope had more diversity than those on the northern slope. The type of plants also changed with elevation, with more turnover in plant species at lower elevations. Overall, temperature and humidity were the main factors influencing plant diversity on the mountain.