Sheppard Lucy J, Leith Ian D, Crossley A, Van Dijk N, Fowler D, Sutton M A, Woods C
Centre of Ecology and Hydrology, Bush Estate, Penicuik, EH26 0QB, UK.
Environ Pollut. 2008 Aug;154(3):404-13. doi: 10.1016/j.envpol.2007.10.040. Epub 2008 Jan 4.
Effects and implications of reduced and oxidised N, applied under 'real world' conditions, since May 2002, are reported for Calluna growing on an ombrotrophic bog. Ammonia has been released from a 10 m line source generating monthly concentrations of 180-6 microg m(-3), while ammonium chloride and sodium nitrate are applied in rainwater at nitrate and ammonium concentrations below 4mM and providing up to 56 kg N ha(-1) year(-1) above a background deposition of 10 kg N ha(-1) year(-1). Ammonia concentrations, >8 microg m(-3) have significantly enhanced foliar N concentrations, increased sensitivity to drought, frost and winter desiccation, spring frost damage and increased the incidence of pathogen outbreaks. The mature Calluna bushes nearest the NH3 source have turned bleached and moribund. By comparison the Calluna receiving reduced and oxidised N in rain has shown no significant visible or stress related effects with no significant increase in N status.
报告了自2002年5月以来，在“现实世界”条件下，向生长在雨养泥炭沼泽上的石南属植物施加还原态氮和氧化态氮的效果及影响。氨气从一个10米长的线源释放，产生的月浓度为180 - 6微克/立方米，而氯化铵和硝酸钠以低于4毫摩尔的硝酸盐和铵盐浓度施用于雨水中，在10千克氮/公顷·年的背景沉积量之上，每年提供高达56千克氮/公顷。氨气浓度>8微克/立方米显著提高了叶片氮浓度，增加了对干旱、霜冻和冬季干燥的敏感性、春季霜冻损害，并增加了病原体爆发的发生率。最靠近氨气源的成熟石南属灌木丛已变白并奄奄一息。相比之下，在雨中接受还原态氮和氧化态氮的石南属植物没有表现出明显的可见或与胁迫相关的影响，氮含量也没有显著增加。
