西藏山地半淋溶土壤分布与大骨节病关系研究

通过西藏大骨节病县与非病县山地耕型褐土和灰褐土各土壤亚类的对比分析表明，山地褐土和灰褐土环境是西藏大骨节病主要土壤类型。其中大骨节病县有3.2万公顷耕种褐土，占全部耕种褐土的89.4%，而非病县仅0.4万公顷，占10.6%；同样，近3.9万公顷的耕种灰褐土分布在病县，占全部耕种灰褐土的97.4%，而非病县仅0.1万公顷，占2.6%。相似的半淋溶耕型土壤环境，雅鲁藏布江南岸多为非病区，北岸多为病区，可能与北岸念青唐古拉山和南岸喜马拉雅山的岩性和成土物质来源差异有关。同时土壤水土流失也可能是影响大骨节病分布的重要因素，水土流失严重的地区多为病区，而非病区多分布在地势较平坦的地区。因此系统研究西藏典型大骨节病区的土壤分异及其土壤侵蚀程度的差异对探讨未来西藏大骨节病的分布与流行有重要意义。

Study on the Relationship Between Kaschin-Beck Diseases (KBD) Distribution and Mountain Semi-Luvisols&rsquo|Distribution in Tibet

Kaschin-Beck Disease (KBD) is an endemic osteoarthropathy distributed from North-east to South-west of China. Most disease areas are located in temperate zone and warm temperate zone with forest brown soil and cinnamon forest soil. Tibet is one of the serious and active areas of KBD now. It mainly distributes in mountain and canyon areas located in wetness and half wetness areas of plateau temperate zone. The cultivated soils are mountain brown soil, mountain cinnamon soil, mountain grey cinnamon soil and plateau shrubby steppe soil. This paper studies the relationship between the KBD distribution and the cultivated cinnamon soil and cultivated grey cinnamon soil distributions through comparison analysis of areas of different subgroups of cinnamon soil and grey cinnamon forest soil in KBD affected counties and non-KBD affected counties. The results show that: mountain cultivated Semi-Luvisols, cinnamon and grey cinnamon soils are main soil types in KBD affected area in Tibet. 89.4% of cultivated cinnamon and 97.4% of cultivated grey cinnamon soils are distributed in KBD counties. For similar cultivated Semi-Luvisols’ environment, KBD tends to distribute in South slopes of Nyainqentanglha Mountain, North bank of Brahmaputra River. While most areas in North slopes of Himalayan Mountain are KBD areas, South bank of Brahmaputra River are non-KBD areas. It indicates that the area affected by KBD is probably related with the lithology and substance’s source of soil mother materials. Further more, the severity of soil and water loss was a likely important factor impacting on KBD distribution in Tibet. Soil loss and erosion is mostly concentrated on KBD affected area, and non-KBD affected counties tend to distribute in areas with flat topography and weak soil loss and erosion. It is important to probe the relationship of KBD distribution and prevalence with the territorial differentiation of soil in typical KBD affected areas and the degree of soil loss and erosion in Tibet.