Quantifying Dry NH3 Deposition to an Ombrotrophic Bog from an Automated NH3 Field Release System
Quantifying Dry NH3 Deposition to an Ombrotrophic Bog from an Automated NH3 Field Release System
复制标题
量化自动化 NH3 现场释放系统向膜营养沼泽的干 NH3 沉积
DOI：
10.1007/s11267-004-3031-3
复制
发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Mark R. Sutton
中科院分区：
文献类型：
--
作者：
I. Leith;L. Sheppard;D. Fowler;J. Cape;Matt Jones;A. Crossley;K. Hargreaves;Y. S. Tang;M. Theobald;Mark R. Sutton
提供一个准确的估计氮沉降的干成分，低N背景，半自然的栖息地，如沼泽和高地沼泽为主的Calluna vulgaris是困难的，但必须与氮沉降在这些社区的影响。为了量化NH3输入到生长在沼泽地上的高沼地植被的田间规模的影响，2002年在Whim Moss（苏格兰边境）建立了一个田间释放NH3熏蒸系统。当满足气象条件（风速>2.5 m s-1，扇形风向180-215°）时，从一个线源沿着60 m的样带释放气态NH3，从而提供了一个NH3浓度随距离源的距离而降低的分布图。在一项补充研究中，使用NH3通量室系统，NH3浓度和表皮电阻之间的关系进行了量化的NH3浓度和微气象条件下的高沼地植被的范围。表皮电阻随NH3浓度的增加而增加，从3.0 μg m−3时的11 s m−1增加到30 μg m−3时的30 s m−1。NH3浓度数据和浓度依赖的冠层阻力被用来计算NH3沉积考虑到叶面湿度。使用NH3浓度依赖性表皮电阻和精炼临界负荷的重要性的影响进行了讨论。
Providing an accurate estimate of the dry component of N deposition to low N background, semi-natural habitats, such as bogs and upland moors dominated by Calluna vulgaris is difficult, but essential to relate nitrogen deposition to effects in these communities. To quantify the effects of NH3 inputs to moorland vegetation growing on a bog at a field scale, a field release NH3 fumigation system was established at Whim Moss (Scottish Borders) in 2002. Gaseous NH3 from a line source was released along of a 60 m transect, when meteorological conditions (wind speed >2.5 m s−1 and wind direction in the sector 180–215°) were met, thereby providing a profile of decreasing NH3 concentration with distance from the source. In a complementary study, using a NH3 flux chamber system, the relationships between NH3 concentrations and cuticular resistances were quantified for a range of NH3 concentrations and micrometeorological conditions for moorland vegetation. Cuticular resistances increased with NH3 concentration from 11 s m−1 at 3.0 μg m−3 to 30 s m−1 at 30 μg m−3. The NH3 concentration data and the concentration-dependent canopy resistance are used to calculate NH3 deposition taking into account leaf surface wetness. The implications of using an NH3 concentration-dependent cuticular resistance and the importance for refining critical loads are discussed.