苏北砂姜黑土与白浆土的形成与生态环境演变的关系

本文试从生态系统的观点,对比研究了苏北剥蚀平原区砂姜黑土与白浆土的发生特征。从研究铁锰结核和石灰结核的成因着手,探讨两种土壤的组合特点及其与生态环境演变的关系。结果表明,季节性氧化还原交替形成大量铁锰结核是这两种土壤的共同特征;石灰结核的组成物质来源于地下水,它是区域性地球化学沉积过程的产物。砂姜黑土与白浆土的组合在该区出现,是在生态环境演变的条件下,又受地形因素与区域性地球化学沉积作用共同影响的结果。

THE RELATIONSHIP BETWEEN GENESES OF LIME CONCRETION BLACK SOIL AND ALBIC SOIL AND ECOLOGICAL ENVIRONMENT

The paper deals with the genetic characteristics of lime concretion black soil and albic soil in North Jiangsu Plain, the features of association of the soils and their relation to ecological environment. This work was made through studying formation of lime and Fe-Mn concretions in the two soils. The results showed that the genesis of the two soils were deeply influenced by ancient ecological environment. It was a common characteristic of the two soils that periodical alternation of oxidation-reduction resulted in the leaching of Fe and Mn and the formation of Fe-Mn concretions. The formation mechanism of the small Fe-Mn concretions (less than 2-3 mm) was different from that of large ones(greater than 5-7 mm). Lime concretions originated from the ground water were the result of regional geochemical sediutenration. So, they occured not only in the two soils but also in the buried palesols of the Quaterary deposits in the region. Finally, the soil association existed in this region was affected by both recent and ancient enmronments.