褐色土是在森林草原气候条件下形成的。这种气候应比较温暖,而且稍微湿润或有明显的干湿季节的变化,地表上以生长草原植物为主,并有旱生森林和灌木丛林的分布。由于森林草原的褐色土型的土壤的形成代表气候的比较温湿阶段,那么就可以推知黄土沉积时其气候条件当更为干燥和寒冷一些。并根据过去在黄土中所发现的脊椎动物化石以 Brown earth is formed in the forest prairie climatic conditions. This climate should be relatively warm, and slightly wet or have obvious changes in the wet and dry season, mainly on the surface of grassland plants, and the distribution of xerophytic forests and shrubbery. As the formation of brown soil in the forest steppes represents a relatively warm and humid phase of the climate, it can be inferred that the climatic conditions of the loess deposits are somewhat drier and colder. And based on the fossils of vertebrates found in loess in the past