内陆高山峡谷区石灰土pH异常现象及成因初探--以九寨沟景区树正、日则沟为例

Preliminary study on pH abnormality and the causes in inland high-mountain gorge——A case in Shuzhenggou and Rizegou,Jiuzaigou area

土壤酸度是研究土壤其它理化性质的基础。目前由于环境污染和大气酸雨的影响，多数岩溶区的土壤呈酸化状况。本文通过采样分析发现九寨沟岩溶沼泽土的土壤酸度变化范围在7．72～9．10之间，普遍高于已有研究的其它岩溶土壤，最大相差达4．85个单位。在26个采样点中，有17个点的pH大干8．00，占总数的65％，呈碱性或强碱性。分析这种现象产生的原因可能主要有四个方面，即地质深层大循环、土壤表层有机物质的转化过程、土壤胶体的作用及大量的钙华沉积。最后提出应多运用现代化的手段（如碳氧稳定同位素、水系沉积物区域化探等）对研究区的各种因子进行进一步分析研究，是可持续开发、利用和保护九寨沟这一世界自然文化遗产的有力保障。

The soil acidity is the foundation that we study other physical and chemical properties of soil. At present, because of environmental pollution and acid rain, the soil is going to be acidified in most karst areas. But by sampling analysis, it is found that karst swamp soil acidity in Sichuan Jiuzaigou is between 7.72 and 9.10, and this is high to other kind of karst soil. The biggest discrepancy reaches to 4.85 units. Among 26 sampling spots, there are 17 spots with pH value exceeds 8.00, about 65% of the total. There may be four reasons for this ： geological and deep layer circle ; conversion process of soil organic materials ; the action of soil colloids and deposition of a great quantity of travertines. It is also put forward in this paper that all factors should be further studied by means of modern method such as steady carbon and oxygen isotope, local chemical exploration to hydro-deposition. All the above efforts are guarantees to sustainable exploitation and utilization as well as protection to Jiuzhaigou.