北京地处黄土降尘区域,现代仍接受着大量的黄土降尘。通过北京山地不同基岩上发育土壤性质的比较发现:由于受黄土的影响,这些土壤的颗粒组成大都以粉粒为主,土体有石灰反应,pH呈微碱性,盐基饱和,与黄土的基本特性相似。证明了黄土降尘作为母质的来源之一,参与了土壤的成土过程,并对土壤性质产生了重要的影响。研究认为,在黄土降尘覆盖区,研究山地土壤,成土母质不应仅考虑下伏基岩,还应该将黄土降尘作为重要的母质因素,考虑这种动态的黄土母质对土壤形成过程和性质的影响。
Nowadays Beijing region is still receiving a great amount of loess dust from northwestern China. By studying and comparing the properties of soils developed on different bedrocks in Beijing mountainous areas, we might discover that in the influence of loess dust, the pH in mostly profile and arrangement was slightly alkaline, the soil from these areas had lime reaction and high base saturation, and its soil particles were mainly consist of silt. The soil we studied had the same essential properties with the loess, it proved that the loess dust, as one of sources of the soil parent material, had been involved in the soil-forming process and had significant impact on soil properties. This paper argued that in the loess dust areas, the underlying bedrock should not be considered as the only parent materials of mountain soils, and the loess dust had to be taken as the essential factor which was the dynamic parent material that played an important role in soil-forming process and soli properties.