土壤化學物對濕潤亞熱帶表層岩溶的影響－野外監測與實驗室模擬

以桂林附近岩溶水文地毬化學試驗場為基點研究了土壤化學條件對岩溶的影響。分別用砂濾琯法，便捷式pH計及CO2濃度計及水化學簡易測定在野外監測了岩石試片的溶解，土壤復蓋條件下土壤及岩溶水pH、CO2濃度及HCO3-濃度。用淋溶柱法實驗室模擬了不同土壤復蓋下岩石試片的溶解。此外，岩溶系統中對植物－凋落物－土壤有機質－土壤CO2－岩溶水HCO3^-－鈣華－岩石的13C進行了採樣和分析。結果表明，土壤pH，土壤有機質（由此影響CO2濃度）及Ca^(2+)飽和度構成影響岩溶活動的土壤化學場、岩溶水HCO3^-和鈣華CaCO3中的C與土壤CO2－C密切相關。因此，岩溶過程涉及土壤發生性碳的作用，它通過大氣－植物－有機質－土壤CO2－岩溶水而在系統中轉移，岩溶水文地毬化學流中存在土壤Ca^(2+)和HCO3在岩溶水的界面交換。據此提出了研究區表層岩溶碳轉移模式。

關鍵字

表層岩溶；土壤化學物；土壤碳

並列摘要

The influence of pedochemical field on karstification was studied in the Karst Hydro-geochemical Experiment Site near Guilin. The dissolution of limestone under soil conditions regarded with pH, CO2 and HCO3^(-1) concentration in the karst system was depicted by means of sand filters, port able pH meter and CO2 gas meter as well as simple hydrochemical measurments. The dissolution was also traced in laboratory under different treatments of soil covers. Futhermore, the different pools of carbon was sampled and analyzed in the karst system of plant-litter-SOC-soil CO2 - karst HCO3^(-1)-traverine-rock. The results showed that SOC (in turn, soil CO2), soil pH and Ca^(2+) saturation constituted a pedochemical field influencing epikarstification and the carbon in karst spring and tuff was closely related with soil CO2 on origin. Therefore, carbon of soil origin was involved in karstification and transferred through the pathway of air-plant-SOC-soil CO2-karst water in the system. Consequently, a model of carbon transfer in the epikarst system of the area was proposed.

並列關鍵字

epikarst ； pedochemical field ； soil carbon

國際替代計量

土壤化學物對濕潤亞熱帶表層岩溶的影響－野外監測與實驗室模擬

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