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以贵州茂兰一种灌丛土壤和一种农业用地土壤为研究对象 ,设置了添加和不添加有机物料处理 ,进行了岩溶作用与土壤碳转移的模拟试验。结果表明 ,土壤 CO2 呼吸排放、土壤淋滤液 HCO- 3排泄及灰岩溶蚀均响应于有机物料的添加。对于无机离子 Ca2 +、Mg2 +来说 ,在不添加有机物料情况下 ,其淋出过程表现为一个较高的活跃可迁移库的释放过程及随后较低风化淋滤的稳定释放过程。在添加有机物料条件下 ,分解释放的 Ca及 CO2 产生的 HCO- 3的排释滞后于土壤呼吸 15天以上。添加有机物料下 ,灰岩溶蚀量均有一定幅度的提高 ,但 Ca(Mg)及 HCO- 3的排释大大增强 ,这一方面表明生物可利用性的碳源的加入促进了系统中岩溶作用 ,并强烈驱动土壤中可交换 Ca、Mg的排释 ;另一方面 ,由于土壤中因呼吸增强而形成的高 CO2 在湿润条件下溶解成为 HCO- 3- C排泄 ,而大大促进土壤碳转移的汇效应。本文的研究结果说明 ,自然土壤因植被的破坏或林地转变为农地 ,可能使岩溶系统的汇效应减弱。
Taking a kind of shrub soil and an agricultural land in Maolan, Guizhou as the research object, a simulation experiment of karstification and soil carbon transfer was set up with or without adding organic materials. The results showed that soil CO2 respiration, HCO3-leaching of soil leachate and limestone dissolution all responded to the addition of organic materials. For inorganic ions Ca2 + and Mg2 +, the leaching process showed a higher release of active and migratory library and the subsequent stable release process of lower weathered leaching without adding organic materials. With the addition of organic materials, the release of HCO-3 by decomposition of released Ca and CO2 lags behind the soil for more than 15 days. Under the addition of organic materials, the dissolution rate of limestone increased to a certain extent, but the release of Ca (Mg) and HCO-3 was greatly enhanced. On the one hand, the addition of carbon source that showed bioavailability promoted karstification in the system , And strongly drives the release of exchangeable Ca and Mg in the soil. On the other hand, high CO2 due to enhanced respiration in soil dissolves into HCO-3-C excretion under humid conditions and greatly promotes soil carbon transfer Exchange effect. The results of this study show that the natural effects of soil degradation due to vegetation or the conversion of woodland to farmland may weaken the sink effect of karst system.