桂林会仙岩溶作用对石灰土壤水锌离子浓度的影响

Effect of Karstification on Concentration of Zn^(2+) in Lime Soil Water at Huixian Guilin

本文通过建立野外观测点,对土壤水锌离子[Zn2+]浓度和岩溶动力系统部分化学参数进行长期监测,探究土壤锌的时空变化规律及其与岩溶作用化学参数之间的关系。结果表明:土壤水Zn2+浓度随土层深度增大而增高,Zn2+浓度在0~30cm处(0.08mg/L)小于30~60cm(0.15 mg/L),且小于60~90cm(0.20mg/L)。在时间变化上,土壤水Zn2+浓度在夏季高于冬季,雨季高于旱季。Zn2+浓度和土壤水pH呈极显著负相关,与降雨量、水量分别呈极显著和显著正相关,与土壤CO2浓度呈显著正相关,与扣除降雨量影响的Zn2+和Ca2+呈极显著正相关。因此,在土壤环境下,强岩溶作用有助于促进岩石或土壤固相中的Zn溶解于水中。岩溶动力作用在驱动碳-水-钙循环的同时,也驱动着微量元素Zn的运移。

In order to understanding the temporal and spatial variation of Zn in lime soil and the relationship between Zn and chemical parameters of karst dynamic system, a fixed position observation have been carried out in Huixian experimental base since June 2008. The results showed that Zn^2＋ concentration increase with the depth of the soil. The average concentration of Zn^2＋ at 0-30cm depth （0.08 mg/L） is lower than that at 30-60cm depth （0.15 mg/L）, and lower than that at 60-90cm depth （0.20mg/L）. The Zn^2＋ concentration of soil water in summer is higher than winter, and that is higher in wet seasons than dry seasons. Zn^2＋ concentration have a significant negative correlation at 0.01 level with soil water pH value, have extremely significant positive and significant positive correlation with rainfall and water respectively, and have significant positive correlation with CO2 in soil air, and have extremely significant positive correlation with Zn^2＋and Ca^2＋ concentration excluding the influence of rainfall. In a word, karstification make more zn in rock and soil dissolved in water under the soil environment, karstification drive the circle of carbon-water-calcium, as well as ruination of soil zn.