Does Elevated Nitrogen and Sulfur Deposition Lead to Net Base Cation Losses in Northern New England Forest Soils?

摘要 提案编号：DEB-9615199 经销商：费尔南德斯，RUSTAD，KAHL，NORTON 研究机构：缅因州大学 本研究的目的是继续治疗和监测的一对分水岭实验在北方缅因州的熊溪，重点是在土壤中的盐基阳离子，特别是钙的变化。 碱性阳离子耗竭是公认的一个潜在的问题，在土壤中，已受到酸性氮沉积，但很少有数据存在良好的控制，长期的实验。 自1989年秋季以来，熊溪流域定期使用硫酸铵进行处理，据信已接近氮饱和。自1993年以来，盐基阳离子和强酸阴离子之间的关系发生了变化，这样不稳定的Ca和Mg可能会耗尽在土壤中的Al损失增加。继续监测将允许测试一系列假设的控制和机制的阳离子保留和浸出在温带森林土壤。

ABSTRACT PROPOSAL # : DEB-9615199 INVESTIGATOR(S) : FERNANDEZ, RUSTAD, KAHL, NORTON INSTITUTION: UNIVERSITY OF MAINE The aims of this research are to continue treatment and monitoring of a paired watershed experiment at Bear Brook in northern Maine, with an emphasis on changes in soil base cations, particularly calcium. Base cation depletion is well-recognised as a potential problem in soils that have been subjected to acidic N deposition but few data exist from well-controlled, long-term experiments. The Bear Brook watershed has been periodically treated with ammonium sulfate since the fall of 1989 and is believed to be approaching N saturation. Since 1993 the relationship between base cations and strong acid anions has changed, such that labile Ca and Mg may be depleted in the soils as Al losses increase. Continued monitoring will allow tests of a series of hypotheses about controls and mechanisms of cation retention and leaching in temperate forest soils.