Abstract:

Based on the problems about the ambiguity of soil genesis, character differentiation and soil distribution in subtropical mountainous areas, this paper takes mountain soil in Zhejiang as an example, and discusses the complexity of vertical variation of genetic characteristics from multidimensional manifestation of desilication, main factors affecting the occurrence of soil reddening and yellowing, and the possible effects of the soil-forming environment change with time on soil genesis. Although there are obvious vertical differentiation in the biological climate and vegetation in subtropical mountainous areas at present, the changes of soil properties and soil types are more complex in the vertical direction because soil formation is comprehensively influenced by both vertical variation of modern climate associated with elevation and temporal and spatial differences of relative soil age caused by topographic evolution. Some of the genetic characteristics affected by the present soil-forming environment could change regularly with altitude, but many of them do not change regularly with altitude due to the influence of paleoenvironment or paleotopography. There is no obvious distinction in the genetic characteristics between red soil group and yellow soil group in the vertical band spectrum. It is concluded that the formation process of red soil subgroup in the subtropical vertical basal zone may be different from those of yellow red soil subgroup and yellow soil group in the upper part of the mountain. Soil color, which is affected not only by the history of soil formation, but also by the current status of soil moisture and vegetation cover, is not necessarily related to weathering intensity. It is difficult to fully understand soil distribution law and soil formation in the subtropical vertical zone by only analyzing the difference of the current soil-forming environments.

Key words: subtropical zone, mountain soil, vertical differentiation, soil-forming characteristics, environmental change, relative age