Negative impact of nitrogen deposition on soil buffering capacity
Negative impact of nitrogen deposition on soil buffering capacity
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DOI：
10.1038/ngeo339
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发表时间：
2008-11-01
影响因子：
18.3
通讯作者：
Baron, Jill S.
中科院分区：
文献类型：
--
作者：
Bowman, William D.;Cleveland, Cory C.;Baron, Jill S.
过去半个世纪的人为氮沉积对欧洲和北美的温带生态系统产生了不利影响，导致土壤酸化和植物生物多样性减少(1，2)。在酸化过程中，土壤释放出钙和镁等盐基阳离子，中和酸度的增加。一旦这些碱性阳离子被耗尽，铝就会从土壤中释放出来，通常会达到有毒的水平。在这里，我们展示了氮沉积实验的结果，该实验表明，斯洛伐克西部塔特拉山脉长期的酸沉积将土壤酸化推向了一个新的酸化门槛，通常与酸性矿山排水土壤有关。我们发现，该地区氮沉积的增加导致盐基阳离子和可溶性铝的枯竭，以及可提取铁浓度的增加。同时，我们观察到氮沉积诱导的维管植物生物量的减少，与地上部钙和镁浓度的下降有关。我们认为，这个地点，以及可能在中欧的其他地点，已经达到了一个新的、可能更具毒性的土壤酸化水平，即铝的释放被进入土壤水中的铁的释放所取代。
Anthropogenic nitrogen deposition over the past half century has had a detrimental impact on temperate ecosystems in Europe and North America, resulting in soil acidification and a reduction in plant biodiversity(1,2). During the acidification process, soils release base cations, such as calcium and magnesium, neutralizing the increase in acidity. Once these base cations have been depleted, aluminium is released from the soils, often reaching toxic levels. Here, we present results from a nitrogen deposition experiment that suggests that a long legacy of acid deposition in the Western Tatra Mountains of Slovakia has pushed soils to a new threshold of acidification usually associated with acid mine drainage soils. We show that increases in nitrogen deposition in the region result in a depletion of both base cations and soluble aluminium, and an increase in extractable iron concentrations. In conjunction with this, we observe a nitrogen-deposition-induced reduction in the biomass of vascular plants, associated with a decrease in shoot calcium and magnesium concentrations. We suggest that this site, and potentially others in central Europe, have reached a new and potentially more toxic level of soil acidification in which aluminium release is superseded by iron release into soil water.